NREL is a national laboratory of the U.S. Department of Energy

Office of Energy Efficiency & Renewable Energy

Operated by the Alliance for Sustainable Energy, LLC

This report is available at no cost from the National Renewable Energy

Laboratory (NREL) at www.nrel.gov/publications.

Contract No. DE-AC36-08GO28308

National Renewable Energy Laboratory

15013 Denver West Parkway

Golden, CO 80401

303-275-3000 • www.nrel.gov

Technical Report

NREL/TP-5000-76849

June 2020

Offshore Wind Electrical Safety Standards 

Harmonization: Workshop Proceedings

Walter Musial,

1 Chloe Constant,1 Aubryn Cooperman,1

Michelle Fogarty,1 Emily J. Chambers,2 Brandon W. Burke,2 

Edgar DeMeo3

1 National Renewable Energy Laboratory 

2 Business Network for Offshore Wind

3 Renewable Energy Consulting Services, Inc.
NREL is a national laboratory of the U.S. Department of Energy

Office of Energy Efficiency & Renewable Energy

Operated by the Alliance for Sustainable Energy, LLC

This report is available at no cost from the National Renewable Energy

Laboratory (NREL) at www.nrel.gov/publications.

Contract No. DE-AC36-08GO28308

National Renewable Energy Laboratory

15013 Denver West Parkway

Golden, CO 80401

303-275-3000 • www.nrel.gov

Technical Report

NREL/TP-5000-76849

June 2020

Offshore Wind Electrical Safety 

Standards Harmonization: Workshop 

Proceedings 

Walt Musial,1 Chloe Constant,1 Aubryn Cooperman,1

Michelle Fogarty,1 Emily J. Chambers,2 Brandon W. 

Burke,2 Edgar DeMeo3

1 National Renewable Energy Laboratory 

2 Business Network for Offshore Wind

3 Renewable Energy Consulting Services, Inc. 

Suggested Citation

Musial, Walter, Chloe Constant, Aubryn Cooperman, Michelle Fogarty, Emily J. 

Chambers, Brandon W. Burke, Edgar DeMeo. 2020. Offshore Wind Electrical Safety 

Standards Harmonization. Golden, CO: National Renewable Energy Laboratory. 

NREL/TP-5000-76849. https://www.nrel.gov/docs/fy20osti/76849.pdf. 
NOTICE

This work was authored [in part] by the National Renewable Energy Laboratory, operated by Alliance for 

Sustainable Energy, LLC, for the U.S. Department of Energy (DOE) under Contract No. DE-AC36-

08GO28308. Funding provided by the U.S. Department of Energy Office of Energy Efficiency and 

Renewable Energy Wind Energy Technologies Office. The views expressed herein do not necessarily 

represent the views of the DOE or the U.S. Government.

This report is available at no cost from the National 

Renewable Energy Laboratory (NREL) at 

www.nrel.gov/publications. 

U.S. Department of Energy (DOE) reports produced 

after 1991 and a growing number of pre-1991 

documents are available free via www.OSTI.gov. 

Cover Photo courtesy of George Nichol, GE Renewable Energy

NREL prints on paper that contains recycled content. 
iv

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Acknowledgments

This study was funded by the U.S. Department of the Interior, Bureau of Safety and 

Environmental Enforcement (BSEE), and the Bureau of Ocean Energy Management (BOEM) 

through interagency agreement number M19PG00026 with the U.S. Department of Energy 

National Renewable Energy Laboratory (NREL). The authors would like to thank the many 

people who contributed to the content of this report, including Cheri Hunter (BSEE), David 

Nedorostek (BSEE), John Cushing (BSEE), Darryl Francois (BOEM), and Sid Falk (BOEM), as 

well as other Bureau team members for their thoughtful reviews, comments, and suggestions. 

We also want to thank the NREL contributors including Tiffany Byrne, who coordinated the 

project schedule and deliverables, and Rebecca Green, who was instrumental in up-front 

planning and coordination. Cyndi Edgley coordinated the logistics for the workshop and 

provided support throughout the project. Technical editing was provided by Sheri Anstedt. Any 

errors or omissions are the sole responsibility of the authors. 

Lastly, we would like to thank all the workshop participants who took time from their busy 

schedules to participate. The list of these participants is contained in Appendix A.
v 

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List of Acronyms

AC alternating current 

AEIC Association of Edison Illuminating Companies 

ANSI American National Standards Institute

API American Petroleum Institute

ASTM American Society of Testing Materials

ATS Acceptance Testing Specifications

AWEA American Wind Energy Association

BOEM Bureau of Ocean Energy Management

BS British Standard

BSEE Bureau of Safety and Environmental Enforcement 

CFR Code of Federal Regulations 

CIGRE Conseil International des Grands Réseaux Électriques (International 

Council for Large Electric Systems) 

CSA Canadian Standards Association

CVA certified verification agent 

DC direct current 

DNV GL Det Norske Veritas – Germanischer Lloyd 

DOE U.S. Department of Energy

EMSR Renewables Electrical and Mechanical Safety Rules (Avangrid internal) 

EPRI Electric Power Research Institute

EN European norm

EMC electromagnetic compatibility

GFCI ground fault circuit interrupter 

GIS gas-insulated switchgear

GW gigawatt

HVDC high-voltage direct current 

ICEA Insulated Cable Engineers Association 

IEC International Electrotechnical Commission

IECRE IEC System for Certification to Standards Relating to Equipment for Use 

in Renewable Energy Applications 

IEEE Institute of Electrical and Electronics Engineers

IP ingress protection

ISO International Organization for Standardization 

ISO independent system operator

kV kilovolt 

LCOE levelized cost of energy 

MW megawatt

NEC National Electric Code (U.S.)

NESC National Electrical Safety Code

NERC North American Electrical Reliability Corporation 

NETA International Electrical Testing Association

NEMA National Electrical Manufacturers Association

NFPA National Fire Protection Association (United States) 

NREL National Renewable Energy Laboratory (United States) 
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NRTL nationally recognized testing laboratory (U.S. Department of 

Labor/Occupational Safety and Health Administration) 

OCRP Offshore Compliance Recommended Practices

OEM original equipment manufacturer

OSHA Occupational Safety and Health Administration (U.S. Department of 

Labor) 

PES Power & Energy Society (part of IEEE) 

PPE personal protective equipment 

PSCCC Technical Committee on Power System Communications and 

Cybersecurity (part of IEEE PES)

RCD residual current device

RSSI Renewables System Safety Instructions 

SDO standards developing organization

SGRE Siemens Gamesa Renewable Energy

SMS safety management system 

S0 IEEE PES PSCCC Cybersecurity Subcommittee 

UL Underwriters Laboratories 

UPS uninterruptable power supplies 

USCG United States Coast Guard

V volt 

VAC volt alternating current 

VDC volt direct current 
vii 

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Table of Contents

Acknowledgments ..................................................................................................................................... iv

List of Acronyms......................................................................................................................................... v

Table of Contents...................................................................................................................................... vii

List of Tables ............................................................................................................................................ viii

Introduction ................................................................................................................................................. 1

1.1 Caveats.......................................................................................................................................... 2

2 Key Findings ......................................................................................................................................... 4

2.1 General .......................................................................................................................................... 4

2.2 Turbines ......................................................................................................................................... 5

2.3 Substations .................................................................................................................................... 6

2.4 Submarine Cables.......................................................................................................................... 7

3 Summary of Plenary Session.............................................................................................................. 8

3.1 BSEE Perspective on U.S. Offshore Wind Electrical Safety Issues ............................................. 8

3.2 Overview of Offshore Wind National Standards Initiative ........................................................... 9

3.3 U.S. Offshore Wind Recommended Practices Status .................................................................. 11

3.4 Original Equipment Manufacturer Approach to Electrical Safety Standards ............................. 11

3.5 Assessment of Secondary System Issues .................................................................................... 12

3.6 Offshore Substations and Equipment Standards and Lessons Learned ....................................... 13

3.7 Overview of Electrical Safety at RWE Windfarms During Construction and Commissioning .. 14

3.8 Assessment of U.S. Electrical Safety Regulations ...................................................................... 14

3.9 Status of AWEA Working Group 5 Recommended Practices for Submarine Cables ................ 15

4 Assessment of Relevant Electrical Safety Standards for Offshore Wind Turbines .................... 17

4.1 A. Safety Design ......................................................................................................................... 18

4.2 B. Safety Procedures ................................................................................................................... 24

4.3 C. Reliability Design ................................................................................................................... 25

4.4 General Comments and Recommendations................................................................................. 28

5 Assessment of Relevant Electrical Safety Standards for Offshore Substations............................................ 30

5.1 A. Safety Design (e.g., Lightning Protection, Switchgear, and Transformers) ........................... 30

5.2 B. Safety Procedures (e.g., Personal Protective Equipment, Lockout/Tagout Procedures, and 

Equipment Guarding) .................................................................................................................. 30

5.3 C. Reliability Design (e.g., Marine Cables and Uninterruptable Power Supplies) ..................... 31

5.4 General Discussion ...................................................................................................................... 31

5.5 A. Safety Design ......................................................................................................................... 32

5.6 B. Safety Procedures ................................................................................................................... 41

5.7 C. Reliability Design ................................................................................................................... 42

6 Assessment of Relevant Electrical Safety Standards for Submarine Cables.............................. 51

6.1 Scope ........................................................................................................................................... 51

6.2 Submarine Cable Route Planning................................................................................................ 51

6.3 Submarine Cable Design, Manufacturing, and Testing ............................................................... 52

6.4 Submarine Cable Installation ...................................................................................................... 54

6.5 Submarine Cable Flammability ................................................................................................... 55

6.6 Operation and Maintenance......................................................................................................... 55

6.7 Decommissioning ........................................................................................................................ 56

7 Next Steps ........................................................................................................................................... 57

8 References .......................................................................................................................................... 58

9 List of Primary Standards.................................................................................................................. 59

Appendix A. Attendee Information ................................................................................................... 66

Appendix B. Workshop Agendas...................................................................................................... 68

Appendix C. Workshop Presentation Materials .............................................................................. 71

Appendix D. Standards Comparison Table ................................................................................... 109
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List of Tables

Table 1. List of Primary Standards Referenced in Report .................................................................... 59

Table A-1. Workshop Attendee List ........................................................................................................ 66

Table B-1. Day 1 – Plenary Session (February 11, 2020) ...................................................................... 68

Table B-2. Day 2 – Breakout Group Discussions (February 12, 2020) ................................................ 70

Table D-1. U.S. and International Offshore Wind Electrical Safety Standards Comparison Table . 110
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Introduction

Offshore wind development activity is accelerating in the United States, with over 10 gigawatts 

(GW) of capacity likely to be installed on the Atlantic Coast before 2030. In addition, states have 

made commitments to procure over 29 GW of offshore wind. Experienced European offshore 

wind energy developers are beginning to make large investments in offshore wind projects in 

American waters, and some U.S. developers have submitted key design documents for regulatory 

review. European offshore wind developers possess extensive experience in other geographic 

markets, which greatly increases confidence that the U.S. offshore wind industry will be 

successful. Nonetheless, existing U.S. electrical standards and European electrical standards are 

significantly different. If not addressed, these differences could impact worker safety. 

To date, there has not been a comprehensive effort to compare U.S. electrical standards to 

European electrical standards in the offshore wind context. The Bureau of Ocean Energy 

Management (BOEM) and the Bureau of Safety and Environmental Enforcement (BSEE), both 

part of the U.S. Department of the Interior, are obligated to address these differences as part of a 

safe and efficient project approval process. 

The federal regulations governing the development of offshore wind facilities, 30 Code of 

Federal Regulations (CFR) § 585, were published in 2009. These regulations outline the 

development process for an offshore wind project in U.S. waters. However, because the U.S. 

offshore wind industry was less mature in 2009, adequate U.S. standards did not exist. For this 

reason, no specific standards were incorporated by reference into 30 CFR § 585. Rather, the 

regulations prescribe that “best practices” be used, with the expectation that these practices 

would evolve as the U.S. offshore wind industry gained experience. 

The formal process of defining “best practices” for the U.S. offshore wind industry has been 

undertaken by the U.S. wind industry (sponsored jointly by the U.S. Department of Energy 

(DOE), BOEM, and BSEE) through the development of recommended practices under a 

standards development process established by the American Wind Energy Association (AWEA), 

pursuant to an agreement with the American National Standards Institute (ANSI). This formal 

AWEA/ANSI approval process is critical for the acceptance of standards by the regulators. U.S. 

ANSI-approved consensus standards and guidelines include vital procedural safeguards that 

guide regulators with respect to project design and approval. These consensus standards can also 

be referenced in potential future revisions to 30 CFR § 585. If appropriate, they can also be 

explicitly quoted by BOEM/BSEE in 30 CFR § 585 or other regulations. 

This AWEA/ANSI U.S. offshore wind standards initiative began in September 2017. The 

AWEA Wind Standards Committee formed an offshore wind subcommittee to oversee the 

development of five working groups to address deficiencies in the current suite of U.S. offshore 

wind standards, including electrical safety. This new suite of recommended practices will (a) 

help clarify design requirements for developers, and (b) enable BOEM/BSEE to create 

regulations that better reflect industry best practices; but publication is not expected until late 

2021. For the near term, there is insufficient guidance in the public domain to establish best 

practices for U.S. offshore projects. 
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The electrical infrastructure of an offshore wind power plant is extremely complex. To 

adequately cover all the electrical subsystems, a broad range of skills from varying disciplines is 

required. In the interest of minimizing delays to offshore wind project approvals, BOEM/BSEE 

commissioned the National Renewable Energy Laboratory (NREL) to convene a group of

technical experts and conduct a workshop to help identify relevant issues. The workshop 

proceedings (this report) are intended to document these matters, such that regulators can use this 

report as guidance while the formal consensus recommended practices are being developed 

through the AWEA/ANSI U.S. Standards Initiative. 

To execute the workshop and write these proceedings, NREL formed a team including internal 

staff, technical staff from the Business Network for Offshore Wind, and NREL consultant Ed 

DeMeo, who is an experienced wind technology expert. The NREL team identified the world’s 

most qualified subject matter experts possessing specific skills vital to our understanding of 

offshore wind facility electrical design and safety, and the harmonization of European and U.S. 

standards. These experts were drawn from the membership of the AWEA/ANSI Offshore 

Compliance Recommended Practice (OCRP) working groups, relevant AWEA wind standards 

committees, recommendations from BOEM and BSEE, and the U.S. offshore wind supply chain 

and developer community. More than 50 technical experts from a diverse range of organizations 

gathered on February 11―12, 2020, at NREL’s Flatirons Campus near Boulder, Colorado. 

During the course of the workshop, these experts shared their knowledge of the constituent 

electric systems that together comprise an offshore wind power plant from the turbines and

offshore substations (i.e., electric service platform) to the subsea electric cables and grid 

connections. 

The workshop organizers compiled input received from workshop presentations and verbal 

discussions into this set of proceedings, with the primary goal of publishing these proceedings as 

a near-term reference to inform project design and approvals. In addition, we envision that these 

proceedings may help inform U.S. industry recommended practices, which are under 

development by the AWEA Wind Technical Standards subcommittee.

1.1 Caveats

This document represents the viewpoints of a wide variety of subject matter experts on the topics 

of electric safety in offshore wind plant design, installation, and operation. Although the authors 

made every attempt to document and translate the views expressed during the workshop and peer 

review process, the interpretations are those of the authors and may not convey the intentions of 

the attendees in all cases. 

The complexity of the design and operation of the electrical systems of an offshore wind farm 

are immense, requiring the application of dozens of standards. Therefore, the recommendations 

made herein represent a first step toward reducing the conflicts that may arise during these 

processes; however, the authors make no claim that these recommendations will eliminate 

conflicts or safety concerns. All projects must engage certified verification agents as required by 

BOEM and BSEE to oversee project development, and, where appropriate, retain the services of 

a third-party owner’s engineer. 

It is important to note that there are several instances in which more than one group at the 

workshop addressed the same topic but may not have identical guidance. In some instances, the 
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recommendations may conflict. In these cases, we attempted to provide both viewpoints to allow 

for the possibility that there may be multiple pathways to achieving the necessary levels of 

safety. In other cases, these viewpoints may not be conflicting but may address separate issues 

on the same topic. For the full scope of the workshop proceedings on a specific topic, reference 

the topic within each of the sections for the corresponding discussion and recommendations from 

the turbine, cables, and substations groups, respectively. In all cases where two different 

viewpoints were offered, we recommend considering both opinions and the developer and its 

certified verification agent (CVA) conduct their own thorough investigation of the issue. 
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2 Key Findings

The workshop’s presentations and discussions benefitted from the extensive breadth and depth of 

expertise of the workshop participants. Major findings and key insights from the workshop 

include the following, which are organized into four categories that parallel the section headings: 

General, Wind Turbines, Substations, and Subsea Cables. 

2.1 General

• The U.S. offshore wind industry is progressing toward construction and operations sooner 

than the availability of supporting standards, guidelines, and regulatory frameworks. For that 

reason, interim regulatory guidelines are needed until comprehensive consensus standards 

can be finalized. The Offshore Wind Electrical Safety Standards Harmonization workshop 

delivered informed input to provide this preliminary guidance. Workshop attendees 

commended BOEM/BSEE for convening this meeting and recommended continuing 

interactions among BOEM, BSEE, the industry, and those pursuing standards harmonization. 

Ongoing engagement is important, as guidelines and best practices will need to be updated 

and refined as the domestic offshore wind sector advances. Recognizing that more formal 

guidance for U.S. projects may not be available until late 2021, the overall aim is to provide 

guidance to help proposed offshore wind projects move forward in the absence of definitive 

U.S. standards. 

• A standards comparison table provided to participants in advance of the workshop helped 

focus workshop discussions. This table was drafted by BSEE technical staff and reviewed by 

several members of the offshore industry prior to the workshop. The table, along with initial 

feedback from the industry, gave rise to a number of questions considered by the workshop 

participants both during and after the workshop. Through discussion of the table, a number of 

standards—both U.S. and European—were added or deleted, and appropriate commentary 

was added to offer interim guidance. That table, amended to reflect the workshop 

deliberations, is included in Appendix D (Table D-1). 

• An initial objective of the workshop was to identify and resolve inconsistencies 

(harmonizing) among U.S. and European standards addressing similar topics. However, the 

workshop discussions generally revealed differences rather than inconsistencies. In many 

cases, the differing standards may achieve essentially the same objective (i.e., a similar level 

of personnel and equipment safety). See Section 2.2 for further discussion. 

• Strong support was broadly expressed for performance-based as opposed to prescriptive 

standards. The attendees generally felt that applying prescriptive standards may impose costs 

without increasing safety. 

• Workshop participants were highly qualified in the topical areas being considered, ranging 

from experts in equipment and safety to certification, with a variety of technical and cultural 

workplace perspectives. 

• In general, worker safety protocols and technical design decisions inform each other; they 

cannot be separated without compromising one or the other. Therefore, we recommend 

ongoing and expanded communication between technical design engineers and safety 

cultures. Both perspectives need to be well-represented and considered together in 

deliberations on project economics. 

• In general, a consensus emerged that U.S. standards, if or where applicable, should be 

applied. However, if adherence to an International Electrotechnical Commission (IEC) 
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standard results in the same level of safety, then the IEC standard should also be acceptable. 

Code mixing should be avoided and ensuring consistency in the use of codes, standards, and 

practices across the complete electrical system (e.g., the onshore substation, offshore 

substation, and wind turbine electrical interface) is paramount. It will be incumbent upon 

project developers to demonstrate to the CVA and regulatory bodies that an adequate level of 

safety will be achieved. Workshop participants indicated that the use of an IEC standard in 

place of a corresponding U.S. standard is more likely to occur in the case of wind turbines 

that already have IEC-type certification, or for submarine cable systems, for which no U.S. 

standard exists, than for substations, which are project-specific, custom-designed 

installations. 

• Competition among standards organizations (e.g., Institute of Electrical and Electronics 

Engineers [IEEE], IEC, AWEA) impedes standards harmonization. These standards 

developing organizations (SDOs) appear increasingly reluctant to defer to similar standards 

developed by another SDO. In the past, standards bodies collaborated on producing 

standards, but this has become less common. Workshop participants would welcome greater 

cooperation and less competition. 

• The terms “high,” “medium,” and “low” voltage are subjective and prone to 

misinterpretation. The terms refer to different voltage ranges in various standards and can 

also vary across jurisdictions. Workshop participants emphasized that when referencing a 

standard or procedure, it is important to verify that the range of voltages covered by that 

standard or procedure is appropriate. 

• Wiring systems and nonsubmarine cables should not be overlooked. BOEM/BSEE or AWEA 

should identify a group to be responsible for reviewing wiring and cabling topics and 

determining which standards are most applicable.

• Although grid integration was not the focus of this meeting and is itself a separate and 

significant topic, it is important to realize that, with injections of 1 GW or more at the landbased point of interconnection, offshore wind power plants will be subject to the North 

American Electric Reliability Corporation’s (NERC’s) jurisdiction. Offshore wind facilities 

will impact system reliability of the land-based receiving independent system operator (ISO) 

or utility. As a result, additional requirements and regulatory standards on offshore wind

systems may be imposed because Federal Energy Regulatory Commission/NERC and 

regional organizations like the Northeast Power Coordinating Council define regulatory 

requirements focused on the bulk energy system and bulk power system, reliability, and 

cybersecurity. 

• The industry should move away from IEC 61400-22, which is superseded by IEC System for 

Certification to Standards Relating to Equipment for Use in Renewable Energy Applications 

(IECRE) OD-501 and -502. Many turbine suppliers have already adopted the new IECRE 

system, and it is expected that most offshore turbines will be required to have IECRE 

certificates going forward. Therefore, IEC 61400-22 is an outdated standard. IECRE OD-501 

and –502 are referenced in Section 2.2 and Section 2.3. 

2.2 Turbines

The following statements summarize the notable, key findings from the turbines group workshop 

discussions: 
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• Turbines are generally purchased “off the shelf,” with a suite of components based on IECtype certification. Replacing components to meet U.S. standards is a design undertaking for 

each model and imposes costs for manufacturers. This practice of replacing components for 

compliance should not be required if the project developer provides justification that the 

turbine, as currently designed, meets the requisite level of safety. Some participants in the 

turbine group were more inclined to favor international standards, whereas others advocated 

for U.S. standards, as done in land-based wind. Participants also expressed that, if a 

component or subsystem has already been certified by a nationally recognized testing 

laboratory (NRTL) in the United States or as part of an IEC-type-certification process, it 

should not be required to undergo repeated evaluation and testing. 

• To illustrate the previous finding, consider spacing of equipment cabinets with dangerous 

interior voltages. In the United States, the Occupational Safety and Health Administration 

(OSHA)under the assumption that dangerous voltages are exposed when the cabinet is 

openedrequires clearances around cabinets. This requirement generally dictates larger 

clearances to aid maneuverability of service personnel. However, IEC standards do not allow 

dangerous voltages to be exposed within cabinets. For example, exposed voltages can be 

accessed with a suitable probe, but not with a finger. As a result, the hazard that is addressed 

by the OSHA standard does not exist in a system designed pursuant to IEC standards, so the 

spacing requirement can be relaxed.

• As a corollary to the two previous findings, applying an IEC standard rather than a 

corresponding U.S. standard simply to reduce costs should only be acceptable if it can be

demonstrated that safety of personnel and equipment are not compromised. 

• Offshore turbine technicians will require a higher level of training to enter and perform work 

on an offshore turbine than technicians that are trained for land-based turbines. This 

additional training should anticipate and cover specific differences between the offshore 

wind power plant’s electrical design and the base training received by U.S. electrical 

workers. 

2.3 Substations

The following statements summarize the notable, key findings from the substations group 

workshop discussions: 

• Because of the similarity between offshore wind substations and offshore oil and gas 

platforms, on most issues, the substation group defaulted to American Petroleum Institute 

(API), ANSI, and IEEE standards. The rationale is that technicians involved in the 

construction and operation of substations will primarily have U.S. backgrounds, training, and 

experience. Also, major suppliers of electrical components are generally able to meet most 

global standards for multiple scenarios. Each substation is a custom product, so sourcing 

components that comply with U.S. standards should not impose undue hardship or costs. 

• API Recommended Practice14F, “Design and Installation of Electrical Systems for Offshore 

Production Platforms” (see 30 CFR § 250.114(c)), was frequently identified as an applicable 

U.S. standard because specific electrical safety requirements for electrical installations

located offshore are covered. These include recommendations for low- and medium-voltage 

switchgear, heliports, weather decks, lighting, transformers, and all types of electrical 

equipment and installations for offshore applications. Other participants observed that the 

API electrical standards are relevant for some aspects of the offshore wind substation, but 

that they were originally intended for offshore oil extraction platforms, which may have 
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different electrical design requirements than offshore wind substation platforms. Reference 

was also made to API RP 14C, “Analysis, Design, Installation, and Testing of Basic Surface 

Safety Systems for Offshore Production Platforms” (see 30 CFR § 250.1628(c)). 

• Different approaches emerged concerning workforce utilization. Some companies use the 

same technicians to service land-based and offshore equipment, whereas others have separate 

specialized land-based and offshore workforces. A prescriptive standard may not be required 

in these instances, as this is more a question of operational strategy. However, it was 

emphasized during the workshop that inconsistencies (code mixing) across codes and 

standards can result in unintended safety-related consequences during 

operation/maintenance.

• U.S. and international standards differ on the need for visual confirmation of contact status 

(i.e., open or closed) for switchgear. This difference needs to be addressed to inform

substation design and construction. In general, offshore wind electrical installations and 

switching equipment must be designed and installed with the appropriate arc flash protection 

and facilities to comply with OSHA lockout/tagout requirements.

2.4 Submarine Cables

The following statements summarize the notable, key findings from the cables group workshop 

discussions: 

• Submarine cables for voltages up to 60 kilovolts (kV) are covered by IEC 63026, which was 

recently published. 

• Existing U.S. standards apply to components of submarine cables, but there is no 

comprehensive U.S. standard for the entire submarine cable system. IEC standards describe 

methods for testing and type-certifying complete cable systems but need to be combined with 

Conseil International des Grands Réseaux Électriques (CIGRE) recommendations for 

electrical and mechanical testing of submarine cables. Acceptance of the relevant IEC 

standards is recommended. 
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3 Summary of Plenary Session

This section summarizes the information exchanged during the plenary session of the workshop, 

which took place on February 11, 2020. The purpose of the plenary session was to provide 

background on the workshop objectives, and to allow members from the industry to present their 

unique, and sometimes divergent, perspectives on the issues. During the plenary session, eight 

speakers presented their viewpoints on issues relevant to electrical design and safety standards 

for offshore wind facilities, and how they are adapting and attempting to comply with U.S. 

market conditions. 

3.1 BSEE Perspective on U.S. Offshore Wind Electrical Safety Issues

A presentation was made by Cheri Hunter, BSEE renewable energy program coordinator, Darryl 

Francois, BOEM Office of Renewable Energy Programs, and David Nedorostek, BSEE senior 

electrical engineer. The purpose of this introductory presentation was to set the stage for the 

workshop, and to explain why it was not only necessary but urgent to develop interim regulatory 

guidelines for U.S. offshore wind installations. The presentation covered the federal regulatory 

background, noting that the Department of the Interior is the federal agency that will be

principally responsible for regulating and enforcing safety and health requirements for renewable 

energy projects located on the Outer Continental Shelf.

Offshore wind projects traditionally follow international standards, but conflicts may arise if 

consideration is not given to the prevailing national and local standards. BSEE and BOEM have 

a due diligence requirement to ensure that the safest standards are used, and the public expects 

these agencies to conduct a robust comparison of U.S. standards with a focus on safety. 

BOEM and BSEE are separate entities but work closely together to review industry submissions, 

such as construction and operation plans, facility design reports (FDRs), and fabrication and 

installation reports related to offshore wind project development within the approval process. 

They noted that U.S. offshore wind recommended practices are currently under development 

through AWEA’s Offshore Wind Standards Initiative, but it is expected that these ANSIapproved recommended practices will not be available until the end of 2021. As such, BSEE 

created a comparison of U.S. versus international electrical safety standards to assist 

BSEE/BOEM engineers in performing a comprehensive assessment of project electrical designs 

for the first U.S. offshore wind projects. This resulted in the creation of the Electrical Safety 

Standards Comparison Table (hereafter “the table”), which included a list of standards that was 

edited and distributed by the NREL team prior to the February 2020 workshop. The original 

table was intended to be a starting point for establishing U.S.-specific expectations for offshore 

wind electrical safety. BSEE indicated that the table will continue to evolve through the feedback 

received from the February 2020 workshop proceedings and as BSEE, BOEM, and the offshore 

wind industry identify best practices through experience. As such, the table was updated by the 

authors of this report based on the feedback received through this workshop and is presented in 

Appendix D. 

The table identifies available standards from the United States, Europe, Canada, and harmonized 

standards that may incorporate international- and U.S-specific requirements. It focuses on what 
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BSEE and BOEM have initially identified to be the most safety-critical electrical equipment and 

procedures. The table is subdivided into the following three categories: 

• Safety Design (e.g., arc flash, switchgear, and transformers) 

• Safety Procedures (e.g., personal protective equipment, lockout/tagout procedures, and 

equipment guarding) 

• Reliability Design (e.g., marine cables and uninterruptable power supplies). 

Workshop participants reviewed the table and considered the following sample questions 

including, but not limited to:

• Does the list of standards focus on most safety critical electrical equipment? 

• Is critical electrical equipment categorized properly? 

• Are all the applicable electrical safety standards for each electrical component captured? 

• Should certification be done by a NRTL for functionality and performance? 

This initial BSEE/BOEM presentation helped frame the discussions throughout the remainder of 

the workshop. The presentation concluded that the next steps were to continue a peer review of 

international and U.S. electrical standards by the experts in attendance and to document these 

discussions. In this manner, these workshop proceedings can inform near-term U.S. project 

development and the ongoing development of ANSI-approved recommended practices for U.S. 

offshore wind. 

3.2 Overview of Offshore Wind National Standards Initiative

Walter Musial is a principal engineer at NREL and is the chairman of the AWEA Offshore Wind 

Standards Subcommittee, which is also known as the Offshore Wind Technical Advisory Panel 

(OWTAP). He presented an overview of the history of U.S. offshore wind recommended 

practices and the current efforts to develop new ones under the AWEA/ANSI rules. The U.S. 

offshore wind standards development effort is jointly sponsored by BOEM and DOE and is 

further supported by the efforts of the Business Network for Offshore Wind and AWEA. 

From 2009 to 2012, the U.S. offshore wind industry, in collaboration with BOEM, NREL, DOE, 

and AWEA, developed a roadmap from existing standards to facilitate the development of “best 

practices” for U.S. offshore wind installations, known as the AWEA OCRP 2012. Over 50 

members of the offshore wind industry participated in the development of AWEA OCRP 2012, 

which covers all aspects of fixed-bottom offshore wind facility development, from design 

through to decommissioning (American Wind Energy Association. 2012). OCRP refers to over 

100 standards, guidelines, and technical specifications. After its publication in October 2012, it 

became the de facto reference for offshore wind development in the United States and has been 

used as an informative framework for regulators, developers, and CVAs. 

However, for several reasons, AWEA OCRP 2012 no longer satisfies the regulatory 

requirements for BOEM/BSEE and the offshore wind development community. First, when it 

was written, the formal process for review and approval by ANSI had not yet been adopted by 

AWEA; this approval process is critical for the acceptance of standards by the regulators, and 

allows the standards documents to be referenced by BOEM/BSEE if appropriate. In addition, the 

scope of AWEA OCRP 2012 was too narrow. It did not cover key aspects of the current U.S. 

offshore wind industry such as floating wind turbines. Finally, in addition to the noted missing 

elements in AWEA OCRP 2012, the document is over 8 years old and does not adequately 
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reflect the knowledge gained through the installation of over 27 GW of offshore wind globally, 

and does not capture the extensive U.S. project development experience that has occurred since it 

was written. 

The AWEA Offshore Wind Standards Subcommittee was formed in 2017 to oversee the 

initiative to upgrade the U.S. offshore wind recommended practices. On October 23, 2017, the 

AWEA Offshore Wind Standards Subcommittee met for the first time, formed five working 

groups, and assigned two conveners to each working group. These groups and their conveners 

are:

• OCRP 1 - Working Group 1: AWEA OCRP Edition 2, under the leadership of Rain Byars 

and Graham Cranston

• OCRP 2 - Working Group 2: AWEA U.S. Floating Wind Systems Recommended Practices, 

under the leadership of Lars Samuelsson and Leif Delp 

• OCRP 3 - Working Group 3: AWEA U.S. Offshore Wind Metocean Conditions 

Characterization Recommended Practices, under the leadership of Mike Drunsic and Lorry 

Wagner

• OCRP 4 - Working Group 4: AWEA U.S. Recommended Practices for Geotechnical and 

Geophysical Investigations and Design, under the leadership of Matt Palmer and Mathieu 

Guinard 

• OCRP 5 - Working Group 5: AWEA Recommended Practices for Submarine Cables, under 

the leadership of Georg Engelmann and Bob Hobson. 

Each recommended practice will provide a roadmap for U.S. offshore wind development in its 

respective area, with a view toward adding transparency and consistency to the regulatory 

approval process, as this can provide benefits to developers, regulators, and the general public. 

These nationally focused recommend practice documents will account for the unique offshore 

conditions on the U.S. Outer Continental Shelf, but they will also be applicable to potential 

offshore wind installations in state waterways (e.g., the Great Lakes). They will provide 

reasonable requirements for commercial offshore development and will cover a range of project 

development activitiesproject design, construction, and deployment practices; operations; 

safety; inspection; and decommissioningwhile anticipating the new and quickly evolving 

nature of offshore wind technology. This suite of offshore recommended practices will help 

clarify the requirements for developers beyond what was provided by AWEA OCRP 2012 and 

will enable BOEM and BSEE to adopt regulatory requirements that better reflect industry best 

practices.

The recommended practice documents that will result from this effort will clarify the 

requirements for offshore wind in the United States. However, they will not be publicly available 

for reference or citation until late 2021. Therefore, the results of this workshop will serve, in part, 

as interim guidance until these OCRP documents are published. OCRP-1 and OCRP-5 cover 

particularly relevant parts of this offshore electrical safety compliance and were described in the 

plenary session later by members of those committees: Albert Fisas and Bob Hobson, 

respectively. 
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3.3 U.S. Offshore Wind Recommended Practices Status 

Albert Fisas, advanced technologies manager for offshore wind at GE Renewable Energy, 

presented an overview of the electrical content in the draft “Offshore Compliance Recommended 

Practices (OCRP)” maintenance document, which will be the second edition that supersedes and 

replaces AWEA OCRP 2012. This revision is currently underway, with over 100 members from 

the international offshore wind community contributing. Albert is a key member of the 

development team and was representing the working group in the absence of its conveners. The 

working group plans to release a draft for public review later this year. A draft of the current 

version of this OCRP-1 RP was distributed among the participants of the workshop for review. 

Albert pointed out that electrical design and safety standards are covered in several parts of the 

revised draft OCRP document, including in some of the general sections (i.e., introductory 

content, design basis, standards hierarchy, terms and definitions, references). Additionally, major 

references reside in the design sections of Chapter 5, including: 

• Section 5.6 (Design of Offshore Wind Turbine) 

o Section 5.6.4 (Electrical Design) 

o Section 5.6.5 (Design for Occupational Health and Safety) 

• Section 5.7 (Design of Offshore Substation) 

o Section 5.7.4 (Electrical Design) 

o Section 5.7.5 (Design for Occupational Health and Safety). 

Note that submarine cables are addressed in OCRP-5, which is currently being developed by 

working group 5. 

The intent of the OCRP-1 working group and the participants of the electrical safety standards 

harmonization workshop was to collectively align with the recommendations within OCRP-1. 

However, workshop participants were not constrained by the content of the OCRP-1 edition 2 

draft, which is still under development. As such, the OCRP-1 working group may potentially 

benefit from the additional insights revealed during the 2-day workshop. We suggest that the 

ORCP-1 consider new references to documents recommended by workshop participants as 

appropriate for offshore wind facility installations.

3.4 Original Equipment Manufacturer Approach to Electrical Safety 

Standards 

Samuel Hawkins, chief engineer for offshore wind emerging markets at Siemens Gamesa 

Renewable Energy (SGRE), gave a presentation titled, “OEM Approach to Electrical Safety 

Standards.” SGRE is the world’s offshore wind turbine leader in terms of total installed offshore 

capacity. A brief company overview was provided, which included a description of their new

turbine, the SG 11.0-193 DD, which is scheduled for commercial deployment in 2022. 

Samuel introduced the methods that SGRE uses for selecting design standards, which includes 

the definition of the company’s global design basis, and a formal evaluation and adaptation for 

the U.S. market. The process commences early in the design phase, to develop and document the 
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design basis for each module of the system. SGRE incorporates best practices from previous 

designs, and regularly updates the process to account for fleet performance, reliability, safety, 

changes and improvements in technology, and revisions and updates to design standards. They 

have a listing of standards applied to each product, which is used during the type certification

process. These standards cover a wide range of topics, including electrical design and safety. 

Health, safety, and environmental design requirements are created, reviewed, and distributed to 

design teams.

In summary, for general global supply, SGRE takes the following actions for offshore wind 

turbines: 

• Turbine designs comply with international codes and standards 

• Turbine models are type certified against this design basis, in accordance with IECRE OD

501. 

Additional actions taken for offshore wind turbines in the United States include: 

• Evaluating the design basis relative to OSHA regulations, United States Coast Guard 

(USCG) regulations, and leading standards from IEEE, National Fire Protection Association 

(NFPA), and others to meet safety objectives

• Evaluating the gaps between the global design basis and U.S. codes and standards on a caseby-case basis. If safety can be improved with reasonable effort, design modifications are 

made. 

The type certificate serves as confirmation that the turbine design is compliant with its design 

basis. 

3.5 Assessment of Secondary System Issues 

Steven Kunsman, director of product management and applications at ABB, delivered two 

presentations during the plenary session. This is a general summary of both. 

ABB is a major global supplier of large electrical hardware components that are used in multiple 

parts of offshore wind farms. As a global supplier, they can comply with any standards 

requirement. In ABB’s view, it is more important to have a transparent specification than to align 

with a given set of standards. 

Steve covered several topics that are relevant to the offshore wind industry as it enters the U.S. 

market. Some of the key points indicated were: 

• Offshore wind farms will need to comply with NERC critical infrastructure protection

regulations. The design impacts of this necessity should be considered. 

• Offshore substations will likely be maintained by U.S.-trained electricians and high-voltage 

electrical workers, the same as for land-based substations. As such, there is a strong need to 

standardize equipment and training around U.S.-based standards (e.g., National Electric Code 

[NEC]) to avoid possible safety concerns. 

• From ABB’s experience, BSEE will likely use OSHA standards first if applicable. BSEE will 

consider international standards and codes if they are more applicable. 
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• IEC 60255 series have been harmonized with IEEE C37.90 series standards, which is a 

positive step. However, this IEC/IEEE cooperation does not appear to be continuing in the 

future. IEC and IEEE are competing more, which is leading to less harmonization and more 

potential conflicts. 

• Steve also chairs the IEEE Power & Energy Society Technical Committee on Power System 

Communications and Cybersecurity (PSCCC) Cybersecurity Subcommittee (S0). He 

indicated that cybersecurity standards, such as CIP-013-1, will be enforceable commencing

July 2020; he cautioned the group not to overlook or downplay the importance of this 

growing issue. 

In 2015, Moffatt & Nichol published a report (https://www.boem.gov/723AA), funded by 

BOEM, that recommended standards to be used for offshore substations. Prior to this workshop, 

there was considerable interest in understanding whether this report had merit and should be used 

as a guide. The presentation by Steve Kunsman and subsequent discussion indicated that this 

report contained a collection of lessons learned from the Cape Wind offshore substation 

development process. Although the report captured all of the standards that were (or should have 

been) used for Cape Wind, the general group discussion indicated that the report may be biased 

toward structural design elements, and that some portions pertaining to electrical design and 

safety may be outdated.

3.6 Offshore Substations and Equipment Standards and Lessons 

Learned 

George Nichol, project director, Grid Solutions for GE Renewable Energy, gave a presentation 

focused on his experience with substation design and implementation, totaling 4.7 GW of 

offshore wind grid connections. His presentation provided background information related 

specifically to offshore wind substations that GE has deployed in recent years in the United 

Kingdom. He elaborated on the project development steps, and provided an overview of the 

Galloper substation, a 336-megawatt (MW), 33/132-kV, offshore substation. This substation and 

land-based delivery system features a state-of-the-art dynamic reactive compensation system 

located at the land-based substation near Leiston, Suffolk, in the United Kingdom, which is 

representative of new project experience. The benefits of this system include appropriate voltage 

control and reactive power support for the Galloper Wind Farm in compliance with U.K. grid 

code requirements. 

Although the substation represented only a fraction of the project’s overall capital cost, the 

presentation stressed the importance of lowering cost to achieve competitive levelized cost of 

energy (LCOE) strike prices in the $50/megawatt-hour range. Going forward, the research 

indicates that standards will continue to evolve as more offshore wind is connected to the grid. 

Grid codes will reflect changing requirements resulting from modeling, testing, and 

demonstrating the technology. Developers will need to pay more attention to the specification of 

nonstandard items and focus on efforts to continuously lower LCOE. In all cases, however, 

safety is essential and has the highest priority. 
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3.7 Overview of Electrical Safety at RWE Windfarms During 

Construction and Commissioning 

Hendrik Berends, senior electrical engineer at RWE, gave an overview about the electrotechnical 

project structure used for installation and commissioning of some selected RWE wind farms 

according to German electrical safety rules. He first provided some background on the recent 

merger between EoN and Innogy to form RWE, which is now the fourth largest developer of 

renewable energy projects worldwide. He reviewed RWE’s internal commitments to health and

safety. Henrik reviewed RWE’s experience with two German offshore wind installations: 

Arkona, a 385-MW wind farm commissioned in 2019 using 6.0-MW Siemens turbines and 

located in the Baltic Sea; and Amrumbank offshore wind farm, which was commissioned in 

2015, using Siemens 3.6-MW turbines and located in the North Sea. He noted that all substations 

are normally unmanned in accordance with DNV GL OS J-201/ST-0145 and were fully 

commissioned in the harbor prior to load-out. 

3.8 Assessment of U.S. Electrical Safety Regulations 

Joseph Cunningham, health & safety compliance manager for ScottishPower (part of Avangrid 

Renewables), presented an overview of Avangrid’s internal Renewables Electrical and 

Mechanical Safety Rules (EMSR), which were established in the United Kingdom, and then 

outlined the challenges for U.S. implementation. He began by describing their safety rules, 

which enable Avangrid to meet minimum legal obligations, but did note that the EMSR often 

exceed minimum legal requirements. These rules are mandatory for all work conducted on sites 

where voltage exceeds 1,000 volts (V) alternating current (VAC), or 1,500 volts direct current 

(VDC). The EMSR are applied to ensure persons working on or near electrical/mechanical 

equipment are safeguarded from inherent dangers arising from those systems. The EMSR 

provide an overarching “philosophy” handbook and are supported by renewables system safety 

instructions. The EMSR may have some parallels with the emerging U.S. federal regulatory 

system, but further comparisons are not made in this report. 

Joseph’s presentation identified the following challenges to U.S. implementation: 

• Safety control boundaries between the developer and the contractor may vary. In the United 

States, The NEC classifies any use of electrical service less than 1,000 V as low voltage. 

• Potential conflicts may arise between a developer’s or operator’s established EMSR and 

wind turbine contractor’s safety system of work/safety rules. This may be especially true if 

BOEM/BSEE establish different requirements for their safety management system (SMS) as 

part of the permitting and approval process. 

• Some conflicts might also be expected in establishing Safety Control Boundaries with a 

turbine supplier. 

• Evaluation of competencies, training, and certification is needed for safety team members 

managing the developer’s safety management system and should consider any union 

requirements. 

• U.S. license requirements for high-voltage switching in offshore wind farms (including landbased assets) and time required to obtain them may present some conflicts.

• Compatibility issues may arise with the “host” ISO’s safety rules at the connection boundary. 
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• Other potential issues may arise as a result of differences in the regulations, such as the use 

of U.S. ground fault circuit interrupters (GFCI), which are more sensitive than the European 

residual current devices (RCDs).

3.9 Status of AWEA Working Group 5 Recommended Practices for 

Submarine Cables 

Bob Hobson, principal designer at NKT HV Solutions and a co-convener of the AWEA Offshore 

Wind Working Group on submarine cables, gave a presentation on the progress and content of 

the draft recommended practices document, titled “Recommended Practices for Design, 

Deployment, and Operation of Submarine Cables in the United States (OCRP-5).” 

Bob recognized his co-convener Georg Engelmann, chief operating Officer at Excipio Energy, 

and Darin Lawton from Burns and McDonnell, who is the secretary for the OCRP-5 working 

group. The working group has deliberated over the correct framework to specify best practices 

for power cable systems in offshore wind farms. Cables are a critical part of an offshore wind 

installation; accordingly, they require proper attention over the entire lifecycle of the power 

plant, from conception to decommissioning. 

Bob acknowledged that the OCRP-5 working group does not need to “reinvent the wheel,” as 

there are ample existing global standards covering the relevant technical requirements. The 

working group need not write new standards but must simply provide a roadmap for the existing 

standards. The short-term approach of the working group is to adhere to functional performancebased standards. 

For the following reasons, the working group has concluded that IEC standards should be 

preferred: 

• IEC-based standards are based on performance and test the complete cable system.

• IEC requires prequalification testing of the entire cable system, and type testing of the entire 

cable system, both electrical and mechanical.

• IEC standards have an established track record of success in Europe for both submarine and 

offshore wind industries. 

• IEEE and other U.S. standards are more prescriptive, and component-based, especially for 

power cables.

• The philosophy of U.S.-based standards is to allow interchangeability of components and 

manufacturers in a cable system. 

• IEC standards are applicable for low-, medium-, and high-voltage systems based on years of 

development and implementation experience. 

The OCRP-5 working group will provide a roadmap to best practices for export cables and 

interarray submarine cable systems. The working group identified more than 34 standards 

organizations and more than 127 standards that may apply to submarine power cables. The goal 

for the OCRP-5 recommended practice is to provide a roadmap, or reference, that leads the 

reader to the appropriate recommended standard. For example, “Cable Ampacity in Duct” 

designers should go to this standard as described by the OCRP-5 for details on how it should be 

applied. The OCRP-5 recommended practice will provide a list of standards with definitive 

useful information that can be directly referenced. It will also provide a list of standards that 
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reference other standards containing instructive information. The recommended practice has 

approximately 100 subject headings related to the “cradle to grave” of an offshore wind facility’s 

submarine power cable system. The OCRP-5 working group has more than 100 members 

contributing from a diverse group of users, of which approximately 20 attend their biweekly 

calls. 

The working group expects to have a draft for AWEA Offshore Wind Technical Advisory Panel

internal review by summer of 2020, with the final document ready to go out for public comment 

later in 2020 following the AWEA/ANSI consensus standard development approach. 

Bob then discussed more general trends and challenges associated with offshore wind submarine 

power cables. He noted that offshore wind project sizes are growing at a rapid rate and the cable 

system designs will be challenged to keep up. For example, the Block Island Wind Farm, the 

only operating offshore wind project in the United States, is a 30-MW project. Projects are now 

being bid between 800 and 1,100 MW. Even larger projects are being planned, with the world’s 

largest offshore wind farm being Dominion Energy’s 2,640-MW proposed array. In addition, 

bigger turbines, 12 MW and larger, are being developed; these machines will challenge 

conventional array cable systems. Floating wind turbines with dynamic cables and deeper water 

are also on the horizon and require additional testing and development. Higher-voltage AC array 

cables are moving quickly to market at 66 kV currently. Future DC array cables are possible at

even higher voltages. As distances from shore continue to increase, we will need longer export 

cables. New high-voltage alternating current and high-voltage direct current (HVDC) offshore 

transmission grid systems will also be needed. We will need standards that work for both the 

developer and U.S. regulators, like BSEE and BOEM. 

With over 29 GW of U.S. state-level offshore wind commitments, U.S. demand in 2030 is 

predicted to be 691 km/year (430 miles/year) to 1,113 km/year (692 miles/year). European 

demand for offshore cables in 2030 is estimated at 1,800 to 2,000 km/year. Lloyd Warwick 

International Claims Database (2002―2019) reports that 83% of the total value of offshore wind

insurance claims concern cable failures, so it was stressed that the U.S. offshore wind regulatory 

system take steps to ensure this record of cable failures is improved upon for U.S. installations. 
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4 Assessment of Relevant Electrical Safety Standards 

for Offshore Wind Turbines

The Turbines Breakout group’s (hereinafter, “the group”) approach was to discuss selected 

topics in depth. Because of time constraints, only topics A-1, A-3, A-6, A-13, C-1, and C-6 were 

addressed during the Turbines Breakout session. Group members were willing to provide 

insights where they felt competent, but some were generally hesitant to endorse or exclude 

specific standards. Postworkshop individual correspondence between Turbine Breakout session 

members and the Turbine Breakout session chair yielded additional feedback on already-covered 

topics and additional topics. 

This section details the topics from the Electrical Safety Standards Comparison Table 

(hereinafter “the table”) that were discussed either: (a) during the Turbines Breakout session of 

the February 2020 workshop, or (b) via postworkshop correspondence between a session 

participant and the session chair. 

Note that in the text boxes associated with each of the upcoming subsections, when the word 

“add” appears next to a particular standard it indicates that the standard was added to the table

found in Appendix D (Table D-1). When “remove” appears in a text box, it indicates that the 

standard in question was removed from the table and is no longer recommended. 

Please also note that the questions and discussion issues raised herein may not always represent 

the most pertinent issues for a given topic and may not characterize the remaining issue(s) 

completely. Nevertheless, they are addressed in the section to best reflect the discussion as it was 

recorded and interpreted. The topics considered are as follows: 

• A. Safety Design (e.g., arc flash, switchgear, and transformers) 

o A-1, Arc Flash/Arc Blast Analysis 

o A-3, Spaces Around Cabinets and Compartments and Equipment 

o A-5, Adjustable Speed Drives 

o A-6, Switchgear (High Voltage) 

o A-7, Switchgear (Medium Voltage) 

o A-9, Transformers 

o A-10, Safety of Machinery 

o A-13, Wind Turbine Electrical Systems 

o A-15, Converter/Inverter 

o A-16, Fixed ladder inside wind turbine. 

 

• B. Safety Procedures (e.g., personal protective equipment, lockout/tagout procedures, and 

equipment guarding) 
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o B-1, Working on or near live equipment 

o B-3, Lockout/Tagout. 

• C. Reliability Design (e.g., wiring methods and uninterruptable power supplies) 

o C-1, Safety (Testing/Fit for purpose) – Acceptance Testing 

o C-6, Cable Flammability Testing 

o C-10, Slip Rings 

o C-11, Alternators, Generators, and Motors 

o C-13, Wiring Within the Turbine 

o C-15, Pitch, Yaw, Other Control Panels 

o C-19, Lighting. 

4.1 A. Safety Design

A-1 Arc Flash/Arc Blast Analysis, Arc Flash Labeling

The Turbines Breakout group indicated IEEE 1584 and NFPA 70E are the most appropriate 

standards for the U.S. market. NFPA 70E and Canadian Standards Association (CSA) Z462 are 

essentially the same document (CSA is the Canadian standard and is harmonized with NFPA 

70E). The group suggested that there was no harm in retaining CSA Z462 in the table since it is 

harmonized with NFPA 70E. 

Discussion Issue: “Arc flash labeling requirements are new in the U.S.” 

Clarification was provided to indicate this labeling effort is standard for U.S. land-based wind 

but may be new to offshore vendors with more experience in other markets. For example, in 

European markets, hazards are addressed in design, lockout/tagout, or via instructions. 

Application of an arc flash sticker is not standard practice in those markets. The suggested 

solution is to rephrase as follows: “Since IEC standards will yield the same safety, use of IEC 

standards should constitute compliance; in addition, the arc flash label can be applied per IEEE 

1584/NFPA 70E.” 

Discussion Issue: “What is needed to have a compliant Safety Management System?” 

The developer shall establish an SMS that complies with 30 CFR 585 and is approved by 

BOEM/BSEE. 

Discussion Issue: “Should BSEE recommend that developers utilize NFPA 70E or IEEE 

approaches on arc flash labeling requirements?” 

The group reviewed the draft of OCRP Working Group 1 (OCRP-1) “5.6.4.7 Arc Flash” and 

agreed with the manner in which arc flash is addressed. BSEE should use the draft as guidance 

on this topic until the OCRP-1 process is completed through ANSI. 
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Discussion Issue: “Are the following approaches for switchgear sufficient?” 

The group concluded that the issue concerns switchgear design and suggested that it be 

addressed in A-6 switchgear (high voltage).

Discussion Issue: “Should the IEC standards listed in the A-1 section of the table in Appendix 

D, IEC 61482-2, IEC TR 61641, IEC 62271-200, IEC 60909-0, be followed for wind 

applications?” 

The suggested solution is to rephrase as follows, “With proper justification, these IEC standards 

could be followed for wind applications.” 

It should be noted that some participants believe that the IEC standards will yield the same level 

of safety as the U.S. standards. Others believe this statement is too broad and that it has not been 

shown that the arc flash requirements and definitions of the two standards approaches are the 

same at all levels. If a sticker is used on IEC-tested and rated equipment, the boundary statement 

and other critical details should correlate to the IEC-defined levels. While either system could be 

acceptable for safety, the boundary or class definitions should not be mixed. Mixing of 

requirements from various IEC and U.S. standards should not be allowed. 

The following questions, although discussed, still remain open issues: 

• Regarding NFPA 70E, which is addressed in OCRP-1, will this standard still be an issue if 

OCRP-1 interpretation is utilized?

• Does using IEEE 1584 for the topic of arc flash conflict with the use of this standard in the 

OCRP-1 document? 

 

4.1.1 A-3 Spaces Around Cabinets and Compartments and Equipment

The group indicated IEC 60364-7-729 is less stringent than OSHA. IEC 62271-200 does not 

cover working spaces around cabinets and is perhaps irrelevant to this section. 

Discussion Issue: “Requirements from IEC 60364, IEC 60204-1, IEC 60204-11, and IEC 

61936-1 require measures to protect from electric shock, such as isolation of hazardous energy 

and the use of protective barriers. Are these the best standard to eliminate the shock hazard?” 

These standards are more relevant to A-13 and do not need to be included in the list for A-3. 

However, if they are used, the hazard is eliminated. 

The group thought it important to clarify that exposed live voltage is not necessary in turbine 

cabinet design. In fact, IEC standards prohibit exposed live voltage, whereas OSHA and 

A-1

Standards addressed: 

• Recommended standards: IEEE 1584, NFPA 70E, OCRP-1 “5.6.4.7 Arc Flash” 

• IEEE 1584: arc flash analysis and methodology for calculating arc flash boundary 

• NFPA 70E: arc flash safety guidance procedure. 
20 

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IEEE/National Electrical Safety Code (NESC) standards require increased space around 

electrical cabinets based on the possibility of exposed live voltages. 

It is suggested that BSEE ask the turbine original equipment manufacturer (OEM) if the turbine 

cabinets have exposed voltage. If yes, then A-3 should be pursued in detail; if not, these 

standards may not be as important or relevant. 

It is also suggested that BSEE consider the safety ensured by the IEC standard to be equal to or 

greater than the IEEE standard. The group reviewed OPRC-1 draft, “5.6.4.6 Working Space 

around cabinets with exposed live voltages,” and found it addresses only cabinets with exposed 

live voltages. The group agreed the minimum distance requirements should only be relevant to 

cabinets with exposed voltage. 

A-5 Adjustable Speed Drives

This topic was not addressed by the group; the individual that provided feedback indicated that 

the standard Underwriters Laboratories (UL) 508C should be removed and replaced by UL 

61800-5-1. 

A-3

Standards addressed: 

• Recommended standards: none explicitly identified

• IEC 60364-7-729 is less stringent than OSHA 

• IEC 62271-200 does not cover working spaces around cabinets and is perhaps 

irrelevant to this section

• IEC 60364, IEC 60204-1, 60204-11, and IEC 61936-1 are more relevant to A-13 and 

do not need to be included in the list for A-3. However, if they are used, the hazard 

should be eliminated.

A-5

Standards addressed:

• Remove UL 508C and replace with UL 61800-5-1. 
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A-6 Switchgear (High Voltage)

The group suggested adding “turbines” to the ‘relevance’ column, adding IEC 62271-203 

because it addresses > 52 kV, and noting that IEEE 1547 refers to grid code compliance and is 

not specific to switchgear design. 

A-9 Transformers

Discussion Issue: “Which standards are acceptable?” 

The original standards table listed NFPA 70B. A turbine-group member with extensive 

certification experience indicates that this is not a product certification standard. Therefore, 

NFPA 70B has been removed from the table. 

Discussion Issue: “When installed inside the tower or nacelle, should a dry transformer with 

nonflammable liquid be used? Should a transformer with “less-flammable” liquid rather than 

“nonflammable” liquid be used?” 

The term “less flammable” appears to be subjective. However, as defined in NEC 450.23, a 

liquid is considered less flammable if its ignition point is 300 °C or higher. This is equivalent to 

a Class K liquid according to IEC 61039. 

A-13 Wind Turbine Electrical Systems

The group suggested adding IEC 61936-1 and UL 6141, and that EN 61400-3 is outdated and 

should be replaced by IEC 61400-3-1 and IEC 61400-3-2. 

The following clarifications were provided: 

• IEC 61400-1 covers the initial design to be type certified 

• IEC 61400-3-1 covers fixed offshore turbines and is used to assess the suitability of the type 

certificate 

A-9

Standards addressed: 

• Recommended standards: none explicitly identified. 

A-6

Standards addressed: 

• Recommended standards: none explicitly identified

• Add IEC 62271-203 because it addresses > 52 kV 

• IEEE 1547 refers to grid code compliance and is not specific to switchgear design. 
22 

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• IEC 61400-3-2 covers floating turbines and is used to assess the suitability of the type 

certificate 

• IECRE OD-502 is an operational document describing a method of approving a design for a 

particular project (i.e., similar to the CVA process) 

• CAN/CSA-C22.2 No. 272 is similar to UL 6141 

• CAN/CSA-C61400-3 is harmonized to an older version of IEC 61400-3 and is not updated to 

harmonize with the 2019 version of IEC 61400-3 that includes 61400-3-1 and 61400-3-2. 

The group suggested this section should list preferred U.S. standards and international standards 

with a caveat that “these international standards may be used with justification.” 

Discussion Issue: “Are the following standards acceptable: CAN/CSA C61400-3, UL 6141, and 

CAN/CSA-C22.2 No. 272?” 

The group provided a response and justification for each: 

• CAN/CSA C61400-3 is redundant with the outdated version of the IEC 61400-3 and is not 

acceptable. 

• UL 6141 is acceptable and should be added. 

• CAN/CSA-C22.2 No. 272 is similar to UL 6141 and therefore is acceptable. 

Discussion Issue: “How should EN 61400-3 be used? Significant revision and expansion of the 

Electrical Systems section is included in the 2019 revision of the 61400-01 wind turbine design 

standard.” 

It is recommended that in general a European norm (EN) version should not be used when an 

IEC version exists. 

Discussion Issue: “Regarding certification, should there be no requirement for repeated 

evaluation and testing by an NRTL? Wind turbine electrical system is type tested and certified as 

part of the type certification process (IECRE OD-501).” 

The suggested solution is to rephrase as follows: “Regarding certification, there should be no 

requirement for repeated evaluation. Wind turbine electrical system is type tested and certified as 

part of the type certification process (IECRE OD-501 or e.g., UL 6141).” If something is 

certified, no reevaluation is needed unless it changes or if there are details beyond what is 

certified.
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The group reviewed the draft of OCRP-1 “5.6.4.1 General Requirements” and finds the 

statements acceptable, although not necessarily complete. 

A-15 Converter/Inverter

Discussion Issue: “Should a low-voltage converter comply with IEC 62477-1 and a mediumvoltage converter with IEC 62477-2?” 

The terms low voltage and medium voltage need to be quantified. IEC 62477-1 is suitable for 

voltages no greater than 1,000 VAC or 1,500 VDC. IEC 62477-2 is suitable for voltages from 

1,000 VAC or 1,500 VDC up to 36 kV AC or 54 kV DC. 

A-16 – Fixed Ladder Inside Wind Turbine

An offshore industry safety manager offers this recommendation: fixed ladders should comply 

with OSHA standards inside the United States and its waters. European standards have not 

provided enough clearances for personnel and in the land-based industry, and OSHA will not 

give a variance for noncompliant ladders from Europe. AWEA has lobbied on this point for 

years and OSHA will not budge. The fixed ladder standard in OSHA is well-established and 

should be utilized in the United States. A participant from a different breakout group also 

expressed support for this recommendation. 

A-13

Standards addressed: 

• Recommended standards: IEC 61400-3-1, IEC 61400-3-2, IEC 61936-1, UL 6141, 

CAN/CSA-C22.2 No. 272, and OCRP-1 “5.6.4.1 General Requirements” 

• Add IEC 61936-1 and UL 6141 

• CAN/CSA C61400-3 is redundant with the outdated version of IEC 61400-3 and 

should be removed 

• EN 61400-3 is outdated and should be replaced by IEC 61400-3-1 and IEC 61400-3-2 

• An EN version should not be used when an IEC version exists. 

A-15

Standards addressed: 

• Recommended standards: none explicitly identified.
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Additional input from an OEM suggested the following: OSHA requirements are prescriptive 

and must accommodate general industry, where the level of personal protective equipment (PPE) 

is not consistent. OSHA’s reluctance to provide a variance on their rules for land-based wind was 

necessary to maintain a precedent that rules, as written, must be adhered to for workplaces where 

OSHA is the agency having jurisdiction. OSHA has not, to date, adopted a performance-based 

approach to safety regulation that permits the use of additional risk-reduction measures to 

achieve a desired safety level. For offshore wind, a developer’s SMS should include basic PPE 

guidance and the use of a helmet when working in a wind turbine, especially when traversing 

fixed ladders. The mandatory use of a helmet significantly lowers the risk of harm as a result of

encroachment into the area around the fixed ladder. It is recognized that the clearance 

requirements from ISO standards are less than those prescribed by OSHA. However, when the 

application of the ISO standards is combined with appropriate PPE, the level of safety meets or 

exceeds what would be accomplished through the OSHA requirements alone. 

4.2 B. Safety Procedures

B-1 Working on or Near Live Equipment

An offshore industry safety manager offers this recommendation: OSHA and NFPA 70E should 

be the only allowable standards for the U.S. market. American technicians and personnel across 

all industries are already trained to, and familiar with, these regulations. These are wellestablished in the United States and manufacturers should not be allowed to dictate safety 

procedures. A participant from a different breakout group also expressed support for this 

recommendation. 

Additional input from an OEM suggested the following: work on live equipment is generally 

prohibited in offshore wind. Instead, written isolation procedures are put in place to ensure that 

hazardous energy is removed from a system before work commences. Technicians are duly 

trained and evaluated on their competence in understanding these energy isolation procedures 

and the application of isolations. This training is a mandatory component of becoming a 

qualified person capable of performing work in an offshore wind turbine. The regime for 

evaluating and enforcing this competency is a necessary part of a developer’s SMS. IEC and ISO 

design standards include strict requirements on the provision of energy isolation points for both 

electrical and fluid power systems, so that such energy isolation procedures may be created and 

followed. 

A-16

Standards addressed: 

• Recommended standards: OSHA 29 CFR 1910.23, OSHA 29 CFR 1910.269(h), ISO 

14122-1, and ISO 14122-4. 
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B-3 Lockout/Tagout

An offshore industry safety manager offers this recommendation: only U.S. lockout/tagout 

standards and practices should be followed. Project owners will not allow anyone who does not 

follow NFPA 70 E and OSHA standards for control of hazardous energies and lockout/tagout to 

work on a project site. A participant from a different breakout group also expressed support for 

this recommendation. 

Additional input from an OEM suggested the following: international standards include 

requirements for the design of equipment for lockout/tagout, which should be considered 

compatible with the process requirements from OSHA and NFPA 70E. These standards include 

IEC 60204-1 (e.g., Section 5.4) for electrical installations, as well as ISO 12100 (e.g., Section 

6.2.11.1) for general machine safety and ISO 4413 (e.g., Section 5.4.7.2.1) for fluid power 

systems (hydraulics). The expression “isolation of hazardous energy” is a commonly used 

reference to lockout/tagout internationally. 

4.3 C. Reliability Design

C-1 Safety (Testing/Fit for Purpose) – Acceptance Testing

The group suggested: 

• IEC 61400-22 be replaced with IECRE OD-501 

• ‘BS’ (British Standard) be removed from EN 61400-22 

• BS PD IEC WT 01 be removed from the table 

• ISO 9001 be added to the table.

Clarification was provided that IEC 61400-1 and IEC 61400-3-1 include commissioning testing 

requirements, whereas other standards include (such as IEC 60204-1) verification and testing 

requirements. CSA SPE-1000-13 is used for field evaluation of electrical equipment. 

Discussion Issue: “Are the following standards most acceptable? DNV GL, CSA, or 

ANSI/International Electrical Testing Association (NETA) standards?” 

B-3

Standards addressed: 

• Recommended standards: NFPA 70E, NFPA 70B, NFPA 70, and OSHA 29 CFR 

1910.

B-1

Standards addressed: 

• Recommended standards: OSHA 29 CFR 1926.960, OSHA 29 CFR 1910 Subparts 

R,S, and NFPA 70 E Ch1 Art.100-130. 
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The group was not familiar enough with the DNV GL, CSA, or ANSI/NETA standards to 

determine which are most acceptable.

Discussion Issue: “Should BSEE recommend that developers conduct tests on electrical 

equipment to determine if it is fit for service before going live?”

The group suggests acknowledging this is already being done. 

C-6 Cable Flammability Testing

The group suggests adding smoke visibility EN 61034-2 (e.g., IEC document 61034-2-2005) to 

the table, and suspects additional relevant standards need to be added to the table as well.

The distinction was made that the United States and Europe prioritize different hazards. The 

United States is more concerned about smoke than the toxicity of the emissions, so it makes 

cables with halogen. By contrast, Europe prioritizes reduction of the toxicity of emissions and 

requires a halogen-free design.

Discussion Issue: “Are all listed standards acceptable?” 

The group noted the standards are not equivalent. The group’s understanding from conversation 

with BSEE is that if OEMs use the U.S. standard, that will be acceptable. Alternately, if OEMs 

elect to use the IEC standard instead, the OEM must justify it. 

The following question, although discussed, is still an open issue: The group’s understanding 

from conversation with BSEE is that if OEMs use the U.S. standard, that will be acceptable. 

Alternately, if OEMs elect to use the IEC standard instead, the OEM must justify it. 

C-1

Standards addressed: 

• Recommended standards: IECRE OD-501 and ISO 9001 

• Replace IEC 61400-22 with IECRE OD-501 

• Remove ‘BS’ from EN 61400-22 

• Remove BS PD IEC WT 01 

• Add ISO 9001. 

C-6

Standards addressed: 

• Recommended standards: none explicitly identified

• Add EN 61034-2 (e.g., IEC document 61034-2-2005). 
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C-10 Slip Rings

The table states that UL 6141 references IEC 60204-1 as compatible. However, the word 

“compatible” could oversimplify the issue, because equipment evaluated to the separate 

standards is not certain to be compatible. UL 6141 explains that testing of the slip ring must 

consider the ratings and certifications of upstream overcurrent protection. A slip ring evaluated 

to UL508 may not be compatible with upstream equipment evaluated to IEC 60204-1. 

UL 6141 states: Typical U.S. overcurrent devices have a 135% overload rating, and IEC 

overcurrent devices often have a 1.45 overload rating. The maximum clearing time permitted for 

most overcurrent protective devices is commonly 1 or 2 hours and depends upon the device type, 

current rating, and applicable standard. 

It is suggested the table comment be changed from “The UL 6141 standard references these as 

compatible” to “The UL 6141 standard accepts either IEC 60204-1 or UL 508 compliance.” 

C-11 Alternators, Generators, and Motors

Similar to C-10, the original standards table states that UL 6141 references the IEC series as 

compatible. Again, the word “compatible” is misleading. 

It is suggested the table comment should be changed to: “UL 6141 accepts compliance with 

either the UL 1004 series or the IEC 60034 series.” 

C-13 Wiring Within the Turbine

Although both IEC and U.S. standards are acceptable, a preference was expressed for use of the 

NFPA standards because U.S. technicians will be trained to those standards. 

In the initial review of this report, another participant suggested there be consistency across the 

turbine, land-based and offshore substation electrical system because the electrical technician 

could work in all areas. Lack of consistency across the entire electrical system could result in 

safety issues. For example, the color coding of wires is inconsistent between IEC wiring tables 

and IEEE wiring diagrams. 

Additional input from an OEM suggested the following: the developer’s SMS should include 

requirements for minimum levels of training for technicians to be considered as qualified persons 

C-11

Standards addressed: 

• Recommended standards: none explicitly identified. 

C-10

Standards addressed: 

• Recommended standards: none explicitly identified. 
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and competent to carry out work on electrical systems. This training must include the ability to 

read and interpret wind turbine manufacturer electrical diagrams and follow written electrical 

isolation procedures. This basic level of training can be used to ensure that wind turbine designs 

that include the use of international standards can be safely installed and maintained. To 

reinforce this, it is necessary that the electrical systems of the wind turbines are fully 

documented, including electrical schematics that match the specific designs installed at a project.

An additional participant emphasized U.S. wind turbine technicians know that wind turbine 

wiring can be in accordance with international standards and consistency, good training, and 

documentation are essential. 

4.3.1 C-19 Lighting

It is suggested the U.S. safety certification standard for luminaires, UL 1598, be added to the 

table. 

4.4 General Comments and Recommendations

Regarding the turbine standards overall, if an offshore wind project is following codes and 

regulations that require NRTL testing, an NRTL should be used. Likewise, if using IEC 

standards, testing should be done with an accredited lab appropriate for those standards. This was 

the general sense of the group’s breakout discussion, but additional input received after the 

workshop indicated differing views on the degree of required testing by an NRTL. These views 

are reflected in the following italicized statement, which, with appropriate variations, has been 

added to a number of the items in the Appendix D Standards Comparison Table: regarding 

certification, components normally come with type-testing documentation from the supplier. 

Some participants recommend against a requirement for repeated testing by an NRTL. However, 

others recommend the following approach: if using U.S. codes and regulations that require 

NRTL certification, then an NRTL should be used to certify. If using IEC standards, then tests 

with alternative accredited labs for those standards may be acceptable.

In general, the group encourages the use of performance-based, rather than prescriptive, 

standards. This common-sense approach will facilitate achieving the shared goal of project and 

worker safety. 

C-13

Standards addressed: 

• Recommended standards: NFPA 70 (NEC) and NFPA 79. 

C-19

Standards addressed: 

• Add UL 1598. 
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It should be expected that deviations from a standard are permissible, but deviations need to be 

justified to BOEM/BSEE. When an OEM deviates from a standard, there should be a mechanism 

to justify the deviation and explain why it achieves an equivalent or better result. 

The group cautions against using vague “high,” “medium,” and “low” terms for voltage (e.g., in 

A-3, A-6, A-7). These terms are subjective and are often defined differently. The group 

recommends that standards be designed for a clearly stated voltage. Regardless of the 

terminology used (low, medium, high), a standard should be applied only when it is applicable 

for the actual voltage range of a component, subsystem, system, or technology in question. 

The group suggests changing the statement in the “Certification” column in A-10, A-13, A-15, 

and C-15 from “Intertek certifies wind turbines to the listed UL and CAN/CSA standards” to 

“There are organizations to evaluate wind turbines to the listed UL and CAN/CSA standards.” 

This change removes identifying a specific company, and uses proper terminology, as these 

organizations “evaluate” rather than “certify.” 

Regarding the development of BSEE’s guidelines for electrical safety, the group provided 

several suggestions to accelerate progress. The original Electrical Safety Standards Comparison 

Table, which was disseminated in advance of the conference, included irrelevant standards, and 

was missing relevant standards. The group expressed that, while the February 2020 workshop 

was a productive exercise, there was not enough time to conduct a complete review of the table. 

Therefore, BSEE should consider all input to make the table as complete as possible. 

Because the U.S. offshore wind industry is moving quickly, the group recommends that 

BOEM/BSEE support more workshops like this one while OCRP recommendations are being 

finalized. Additionally, BOEM/BSEE should engage with the land-based wind community and 

NRTLs to incorporate their experience integrating the international land-based wind industry 

into the U.S. market. 

Finally, BOEM/BSEE should engage in face-to-face meetings with individual 

industry/stakeholder representatives to learn more and gather information. These face-to-face 

events will facilitate a more effective and efficient transfer of knowledge than emails and 

documents. They are also likely to yield more candid sharing of information than in a group 

setting. Once BOEM/BSEE collect information in individual meetings and identify common 

concerns, a group meeting should be convened to achieve consensus within the OSW industry. 

A question for BSEE: Do the turbines and substations groups need to come to consensus on the 

standards? The philosophy of OCRP is that turbines are generally mass-produced and consistent 

with IEC-type certifications, whereas substations are project-specific custom designs. 

Consequently, standards language regarding turbines uses more permissive suggestions (i.e., 

“should”), whereas standards language relevant to substations employs more prescriptive 

requirements (i.e., “shall”).

One OEM indicated it is following the same process for their offshore work as for their landbased work in the United States and uses an IEC-type certificate + NEC-UL base design. 
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5 Assessment of Relevant Electrical Safety Standards for 

Offshore Substations

The following topics from the Electrical Safety Standards Comparison Table (hereinafter “the 

table”), found in Appendix D (Table D-1), were discussed during the substations breakout 

session of the February 2020 workshop. Additional input from the substations breakout group 

(hereinafter ‘the group’) was sought via correspondence subsequent to the workshop. 

Note that in the text boxes below, when the word “add” appears next to a particular standard it 

indicates that the standard was added to the table. When “remove” appears in a text box it 

indicates that the standard in question was removed from the table.

Please also note that the questions and discussion issues raised herein may not always represent 

the most pertinent issues for a given topic and may not characterize the remaining issue(s) 

completely. Nevertheless, they are addressed in the section to best reflect the discussion that was

recorded. The topics considered are listed as follows. 

5.1 A. Safety Design (e.g., Lightning Protection, Switchgear, and 

Transformers) 

• A-1, Arc Flash/Arc Blast Analysis 

• A-2, Emergency Stop – Design

• A-3, Spaces Around Cabinets and Compartments and Equipment 

• A-4, Electrical Safety Equipment (GFCI – RCD)

• A-6, Switchgear (High Voltage) 

• A-7, Switchgear (Medium Voltage) 

• A-8, Switchgear (Low Voltage) 

• A-9, Transformers

• A-10, Safety of Machinery 

• A-11, Lightning Protection 

• A-12, Electrical Enclosures/Control Panel (Degrees of Protection) 

• A-14, Fire Prevention and Fire Protection 

• A-15, Converter/Inverter 

• A-16, Fixed Ladder Insider Wind Turbine. 

5.2 B. Safety Procedures (e.g., Personal Protective Equipment, 

Lockout/Tagout Procedures, and Equipment Guarding) 

• B-1, Working on or Near Live Equipment 

• B-2, PPE 

• B-3, Lockout/Tagout

• B-4, Equipment Guarding (Energized Component).
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5.3 C. Reliability Design (e.g., Marine Cables and Uninterruptable 

Power Supplies)

• C-1, Safety (Testing/Fit for purpose) – Acceptance Testing 

• C-2, Wiring Methods (High Voltage) 

• C-3, Wiring Methods (Medium Voltage) 

• C-4, Wiring Methods (Low Voltage) 

• C-5, Wiring Methods 

• C-7, Harmonics 

• C-9, Uninterruptable Power Supplies (UPS) 

• C-11, Alternators, Generators, and Motors 

• C-14, Surge Protection/Suppression Component 

• C-19, Lighting 

• C-20, Illumination Levels for Emergency Evacuation 

• C-21, Emergency and Standby Power Systems 

• C-22, Power Sockets and Plugs 

• C-23, Cable Trays 

• C-24, Cable Cleats for Electrical Installations

• C-25, Cathodic Protection 

• C-26, Grounding and Bonding. 

5.4 General Discussion

The substations breakout group began by identifying topics that group members deemed most 

pressing, or controversial, regarding offshore substations. The group identified the following 

topics as most pressing: 

1. IEC vs. IEEE

2. A-1: Arc flash/arc blast

3. A-3: Space around equipment (low voltage) and working online equipment 

4. Standards for drawings/schematics and associated worker training 

5. A-6: High-voltage and low-voltage switchgear (personnel and equipment) 

6. NRTL certification for offshore substations. 

After identifying the previously mentioned key topics, the substations breakout group discussed 

all standards applicable to substations in the Electrical Safety Standards Comparison table. A 

total of 32 standards were discussed. Remaining standards were not addressed for different 

reasons, some because they were more appropriately considered by the turbines or cables 

breakout groups, and some because more clarification or information was necessary to 

comprehensively address the applicable standards. For example, the category name for that 

standard may have been too vague or broad to be able to determine which standards are 

applicable for that topic. 

Standards C-3, C-4, and C-5, regarding wiring methods, were one exception to this process. 
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At the outset of the workshop, the substations group delegated these standards to the cables 

group for consideration. After the cables group reviewed C-3, C-4, and C-5, it was determined 

that the substation group was better suited to address these topics. 

The requirements for NRTL certifications were discussed frequently during the workshop. 

References to these discussions can be found in greater detail in the upcoming discussions for 

each topic. However, one participant commented that, in general, NRTL certifications do does 

not appear to be a requirement for engineered systems, such as fire protection systems, or for 

some components within the system (e.g., the regulators). The following recommendations were

noted but further discussion may be required: 

• NRTL certification of individual components shall be required only if there is a 

commonly used certification standard for that component. 

• The entire system does not need to be NRTL certified, only the individual components. 

• Systems can be comprised of components certified by different NRTLs. 

Note that in general, the substations breakout group defaulted to answer the question: “Are the 

standards listed in the Standards Comparison Table (Appendix D) applicable and or acceptable 

for this topic?” (in terms of substation electrical safety), but other discussion issues were 

considered on a case-by-case basis, especially if an issue was specifically listed in the table. 

5.5 A. Safety Design

A-1 Arc Flash/Arc Blast Analysis

The group agreed that arc flash is a critical issue. There was consensus that the small spaces in 

offshore substations make arc flash challenging to address. The group agreed that the substation 

design must account for the arc flash boundary for worker safety. It was noted that the arc flash 

boundary would be lower for offshore substations because of the space constraints.

The appropriate PPE would be dictated by the equipment used and space needed, which is 

unique to each substation design. Some participants recommended that land-based standards for 

arc flash should be used; universal agreement on this point could not be reached. 

The group expressed that IEEE 1584 has already addressed this issue in the OCRP document. 

Some members of the substation group expressed concern that relying upon IEEE 1584, for arc 

flash in particular, may conflict with the revised OCRP document. This still remains an open 

issue. 

The group also recommended referring to the general requirements for NFPA 70E and ANSI 

specifications for both equipment and PPE. Additionally, it was noted that within NFPA 70E, 

IEEE 1584 is referenced for the calculation of arc flash/blast risks. It is important to note the 

distinction that IEEE 1584 is the evaluation and calculation methodology for arc flash, whereas

the practice of arc flash mitigation and personnel protection is in NFPA 70E. 

Additionally, other participants recommended that API RP 14F be utilized for the working 

clearances around electrical equipment as defined in this standard. 
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The group was in agreement that the purpose of this standard is for arc flash safety guidance 

procedure and workplace safety guidance. There was agreement that the outlined 

procedure should be followed, as it directs the user toward ANSI standards. 

There was no discussion regarding CSA Z462, other than the fact that it remains applicable to 

this topic.

A-2 Emergency Stop — Design

The group debated the precise definition of emergency stop, and how far this process may 

extend. It was agreed that emergency stop can be defined as de-energizing the system. Some 

participants from this group went so far as to recommend that “emergency stop” be replaced by 

“remote de-energization,” stating that a system should be in place to open all the line-side 

breakers in an offshore substation from a land-based location. Additionally, it was noted that the 

resolution to the definition of “emergency stop” has already been addressed in DNV GL 

standards; although, these standards were not specified by the group discussion. 

It was also debated whether or not an emergency stop system includes emergency evacuation 

systems, and if manned or unmanned facilities should be addressed. This discussion did not 

reach a clear resolution. 

The group agreed that every facility must have an emergency stop system in place. Although the 

issue was not fully resolved, the group made progress in asking questions to help define what an

emergency stop means, such as: 

• What equipment in the offshore substation needs to be shut down to maximize safety for the

personnel and the environment? 

• When personnel return to the substation facility, what equipment needs to be de-energized to 

ensure safety? 

Overall, there was general agreement that the purpose of an emergency stop system is for the 

protection of the environment and personnel. No standards were specifically recommended to be 

added or removed from the list in Table D-1. 

A-1

Standards addressed: 

• Recommended standards: IEEE 1584, NFPA 70E, and CSA Z462 

• IEEE 1584: arc flash analysis and methodology for calculating arc flash boundary 

• NFPA 70E: arc flash safety guidance procedure and personal protection guidance 

• Add: API RP 14F: working clearances around electrical equipment.

A-2

No standards were explicitly addressed during the discussion. Appendix D applies. 
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A-3 Spaces Around Cabinets and Compartments and Equipment

The group decided it was necessary to agree on a definition for low, medium, and high voltage. 

The group agreed with the NEC definition, which defines voltage classes as follows: 

• Low voltage: < 1 kV 

• Medium voltage: 1–52 kV 

• High voltage: 52+ kV. 

All participants in the electrical safety standards workshop generally agreed that the voltage for 

equipment should always be specified, rather than relying on subjective low-, medium-, or highvoltage language. 

Upon addressing the voltage classification, the substation group also discussed the difference 

between troubleshooting exposed versus unexposed live (i.e., energized) parts. There was a 

difference of opinion regarding troubleshooting of live system components. A participant argued 

that one cannot troubleshoot a de-energized component, whereas others agreed that the part must 

be de-energized and grounded when troubleshooting for safety. Another participant 

recommended that in either case, whether energized or de-energized, the electrical equipment 

should be tested per the manufacturer’s recommendations. 

The group generally agreed that spaces around cabinets, compartments, and equipment are 

primarily an issue for low-voltage panels. This is because high-voltage components are typically 

not exposed. Regarding egress and ingress, the group recommended that the offshore substation 

health, safety, and environmental plan should address the voltage class. There was general 

agreement that, during the design phase, the full lifecycle of the project and equipment should be 

considered, including the location for installing the switchgear. 

A concern was raised about whether the battery room would be considered a classified zone if 

API 14F is mandated, knowing that classifying the battery room would greatly increase costs. 

The question still remains as to which standard should be used for calculating acceptable 

hydrogen levels without leading to a classified zone. 

The group did not fully address which standards are applicable for medium voltage. 

A-3

Standards addressed: 

• Recommended standards: NEC NFPA 70E Articles 110.26, 110.34 

• Low-voltage NEC (NFPA 70) 

o NFPA 70: national electric code for low-voltage and high-voltage gear

o NEC: smaller distances. 

• Add: API RP 14F, as this allows smaller distances for low and medium voltages than

required by NFPA
35 

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A-4 Electrical Safety Equipment (GFCI – RCD) 

The group acknowledged that offshore locations are not formally within OSHA’s jurisdiction (as 

a result of earlier agreements made bilaterally between BSEE and OSHA) but that BSEE will 

enforce OSHA regulations offshore to ensure personnel safety. With respect to using GFCI 

versus RCD, it was recommended that the NEC requirements be followed. It was noted that 

additionally, NEC could also be used for PPE. Another participant recommended that NEC be 

applied to all electrical systems in the offshore substation of 600 V or less.

A-6 Switchgear (High Voltage)

The group reinforced the need to precisely define the low-, medium-, and high-voltage classes 

before discussing high-voltage switchgear because various jurisdictions where offshore wind 

turbines might be installed often define voltage classes differently. Some countries have different 

voltage specification brackets for these voltage terms, whereas other countries do not distinguish 

the voltage with the terms low, medium, and high at all. 

The group ultimately reached a general agreement that, from a safety perspective, low and high 

voltage is recognized. By contrast, for operating equipment, the terms low, medium, and high 

voltage are recognized. It was not clear to the substations group whether this “safety vs. 

equipment” distinction exists only in the United States. 

There was some alignment among the substation participants to accept IEC standards for 

switchgear and associated equipment. It was, however, noted that U.S. and European standards 

differ regarding the need for visual confirmation of contact status (i.e., open or closed) for 

switchgear. This difference needs to be addressed relative to substation design and construction. 

However, one participant disagreed and stated that ANSI and UL switchgear and Merchant 

Category Code standards are preferred over IEC standards. 

There was additional conversation regarding using IEC’s gas-insulated switchgear (GIS) (e.g., 

viewing windows). It was noted that the IEEE C37.122 standard does not appear to be fully 

implemented by any vendors of GIS above 52 kV. All available GIS at the high voltages 

required for an offshore substation are built and tested to IEC 62271. Therefore, vendors can 

customize IEC’s GIS to meet additional requirements of IEEE but the Factory Acceptance Tests

are performed according to IEC and the tests are different from IEEE. 

One participant noted that there are gaps in IEEE C37.122 and recommended using this standard 

in conjunction with IEEE C37.21. It was suggested to allow the use of fully IEC- compliant local 

control cabinets or hybrid local control cabinet designs that are built to IEC standards, but that 

they should also meet all of the practical requirements of IEEE C37.21. 

A-4

Standards addressed: 

• Recommended standards: NFPA 70E 

• NFPA 70E: for low voltage and safety

• Add: API RP 14F. 
36 

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Additionally, it was suggested by one participant that if LCCs are fully IEC compliant, then IEC 

cables should be used between GIS and LCCs. If a hybrid IEC/IEEE LCC is used, then 

type/colors of cables used will ensure a consistent design. 

Finally, there was discussion of NRTL testing of switchgear. Two participants of the substations 

group provided input on NRTL testing as follows: for systems at 600 V or less, the NEC should 

be followed. Higher than 600 V, the NESC should be followed. NRTL testing is not required. 

The basis for this is that NRTL testing for components above 34.5 kV does not appear to exist. 

NESC does not require NRTL certification. There are limited manufacturers of components up to 

34.5 kV, so adding this additional requirement would be too restrictive for substation designers 

and may have negative unintended consequences on cost and safety. At 600 V and below, NRTL 

certified components are common, and NRTL certification demonstrates compliance with NEC. 

One can also use components that are not NRTL certified, but in these cases demonstration of 

NEC compliance must be made.

A-7 Switchgear (Medium Voltage) 

The group’s consideration of medium voltage switchgear was brief, and mainly led to a NRTL 

discussion. The substations group concluded that, if IEC standards are used, the equipment must 

still be NRTL certified. 

Similar to the argument made in A-7, the same comment on NRTL certification was made for 

MV switchgear. For systems at 600 V or less, the NEC should be followed. Higher than 600 V, 

the NESC should be followed but NRTL testing is not required. At 600 V and below, NRTLcertified components are common, and NRTL certification demonstrates compliance with NEC. 

One can also use components that are not NRTL certified, but then demonstration of NEC 

compliance must be made.

One participant noted that as the tests for IEC-type switchgear are different, the previous IECtype tests may be not applicable and the National Electrical Manufacturers Association 

A-6

Standards addressed: 

• Recommended standards: IEEE C37.122 

• Add: IEEE C37.122, for gas-insulated switch gear, specific to high voltage

• Add: IEC 62271 

• Remove: IEEE C37.20.2: for medium voltage only. 

A-7

Standards addressed: 

• Add: IEEE C37.20.2, IEEE C37.20.09: for ANSI MV 

• Add: IEEE C37.20.7: if using arc gear for LV and MV; must be NRTL certified as well. 
37 

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(NEMA)/ANSI tests will need to be performed to comply with the requirements of the ANSI, 

IEEE, and UL standards. 

A-8 Switchgear (Low Voltage)

The low-voltage switchgear conversation led to questions about the scope of the term. For 

example, should motor control equipment and exhaust fans be considered low-voltage 

switchgear? Some participants stated that motor control equipment is covered by the UL 845 

standard and is not switchgear, and that it does not have the same requirements as ANSI 

C37.20.1 (i.e., it does not have a short time short circuit withstand rating, wherein low-voltage 

switchgear requires a 1-second withstand rating.) At the conclusion, there was still some 

question about whether motor control equipment should be classified as low-voltage switchgear. 

It remains unclear whether switchgear for exhaust fans should be included in this category. 

The group came to a consensus that NEMA standards will be included with the other 

recommended standards. However, a path should be made for acceptance of IEC standards as 

well, as it was noted that IEC low voltage takes up considerably less space, and conserving space 

is important for offshore substations in particular. Additionally, the group acknowledged that UL 

has adopted many of the IEC standards, specifically IEC 947. 

A-9 Transformers

The group first agreed on the scope of what equipment and accessories would be considered 

within the term “transformers” for the purpose of addressing this standard. From this discussion, 

there was alignment that the transformer and its accessories including reactors, circuit breakers, 

GIS equipment, and lightning protection would be considered. It was not unclear if shunt 

reactors should also be included in this list of transformer accessories. Although, it was 

recommended by one participant that the use of IEC transformers and shunt reactors, including 

IEC control cabinets, should be permitted. 

The group came to a general agreement that the consideration of flammable liquids, open or 

closed systems, and other issues depends upon the substation design specifications. There was 

agreement that most offshore components are located in enclosed indoor spaces, though some 

transformers are outside. This is a function of the “semiclosed” versus “semiopen” design, which 

is often country-specific. Structural design of the transformer was discussed. All of the design 

A-8

Standards addressed: 

• Recommended standards: UL 891 (for low-voltage switchboard) 

• Add UL 508: enclosed protection systems and enclosed cabinets 

• Add UL 845: motor control 

• Add UL 1558 

• Add UL 1053: safety covering ground fault protection

• Remove: IEEE C37 series—all does not apply.
38 

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questions are left to the developer to address as design specifications, including the 

“nonflammable” or “less flammable” liquid issue. 

One participant recommended that if IEEE transformers are specified, special attention must be 

given to the following: a) plug-in bushings b) oil-SF6 bushings (if used), and c) control cabinet 

interfaces. 

Additionally, another participant recommended using IEC 62271-211 for interfaces between a 

gas-insulated busbar and transformer bushing (oil-SF6), and that special attention is required 

when using IEEE transformers to ensure there are no IEC/IEEE interface issues. 

Other participants addressed the standardization between European and U.S. standards regarding 

transformers. One participant added that until harmonized standards between IEC and IEEE 

become available, n-load tap changers should be designed and tested to meet IEC standards. Yet 

another participant noted that until there are more U.S. suppliers of high-voltage transformers 

accessories, compliance with European standards should be permitted. 

A-10 Safety of Machinery

For the purposes of this workshop, the group limited the term “machinery” to substations only, 

and specifically excluded turbines from the discussion. The group agreed that it would be 

beneficial to classify machinery as either necessary or backup systems. There was alignment that 

backup systems include air compressors; heating, ventilation, and air conditioning systems and 

ventilation systems; backup generators (diesel); and other ancillary systems. Fire detection, gas 

detection, and fire suppression systems are considered necessary machinery. Although this was 

the majority of the group’s definitions for classifying machinery, there were differing opinions 

that separated machinery into ancillary systems, and emergency response or emergency 

shutdown systems. The classification of machinery for the purpose of this discussion remains an 

open issue. 

The substations group was challenged in addressing the standards listed because different 

standards apply for different types of equipment. 

A-9

Standards addressed: 

• Recommended standards: IEEE/ANSI C57 series

• C57 series: for low-voltage transformers and reactors. 

A-10

No standards were explicitly addressed, discussion only. 
39 

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A-11 Lightning Protection

Some members of the group noted that offshore oil and gas platforms generally include limited 

lightning protection measures. For offshore wind substations, the group recommended the 

following standards. 

A-12 Electrical Enclosures/Control Panel (Degrees of Protection) 

The group reached consensus that this category refers to low-voltage electrical enclosures and 

control panels only. The Ingress Protection (IP) rating of these enclosures and control panels was 

discussed, in addition to the incorporation of any fiber optic cables within these fixtures. The 

substations group was not aware of any ANSI standards concerning integration of fiber optic 

cables into power cables.

A-14 Fire Prevention and Fire Protection 

The substations group addressed who is responsible for fire protection, prevention, and 

suppression. The group generally agreed that fire suppression is driven by insurance company 

requirements, whereas fire protection is overseen by BSEE. In both cases, the substation’s 

emergency response plan outlines these responsibilities, and outlines the contractor’s 

responsibilities in the event of an offshore substation fire. The group agreed that it is the 

substation operator’s responsibility to ensure that an emergency response plan is in place, and 

that the emergency response contractors are properly informed as to what regulatory documents 

need to be submitted regarding the fire protection and prevention plan. One participant 

recommended that fire detection should be required, but the installation of fire suppression 

systems be provided only after a proper “As Low As Reasonably Possible” analysis, thereby 

demonstrating the need and value of such a system. 

The group also discussed NRTL certification with respect to fire protection and prevention and 

agreed that NRTL certification is required for fire protection. When and how to follow 

manufacturer’s certifications was also considered. The group reached consensus that the 

manufacturer’s certification can generally be relied upon. However, if the manufacturer does not 

A-11

Standards addressed: 

• Recommended standards: consider IEC 61400-24 and NFPA 780 (sparing standards) 

• Add: IEEE 998 - lightning protection for (land-based) substations. 

A-12

Standards addressed: 

• Recommended standards: UL 508A, NEMA ANSI/IEC 60529, NEMA 250 

• UL 508A: enclosed assembled equipment 

• NEMA ANSI/IEC 60529

• NEMA 250: rating. 
40 

This report is available at no cost from the National Renewable Energy Laboratory at www.nrel.gov/publications.

operate in the country where the equipment is installed, then the equipment in question must be 

re-certified to adhere to local requirements. For example, offshore wind equipment manufactured 

in Germany would be required to obtain NRTL certification before it could be used in a U.S. 

offshore wind installation.

It is important to note that in Europe, fire protection/suppression is generally incumbent upon 

insurance companies. Regarding fire alarm system control, one participant commented that 

NFPA 2001 calls for a local logic controller for a fire extinguishing system controller. For 

typical European projects, the control of this system is under the fire alarm system, which

minimizes the installation cost as well as the size/weight of the equipment installed on the 

offshore substation, and maintenance requirements. Therefore, it was suggested to allow the fire 

alarm system to control the fire extinguishing system equipment directly rather than using a 

separate fire extinguishing system controller. Another participant also recommended to allow 

European fire ratings for walls and penetrations for passive fire protection design. 

Regarding helideck firefighting systems, one participant added that the U.S. standard for the 

helideck firefighting system, NFPA 418, requires a duration of a 10-minute (min) discharge; 

thus, a larger, heavier skid than CAP 437 (10 min in NFPA 418 vs. 5 min in CAP 437). The 

USCG has recognized CAP 437 as an acceptable alternative to the helideck deck firefighting 

system with respect to CFRs. Therefore, it was recommended that both CAP 437 and NFPA 418 

are acceptable, while noting the differences in discharge timing. 

A-15 Converter/Inverter

The substations group did not address this standards category in depth. One participant 

commented that there are specific requirements for inverters to be operated and integrated into 

the U.S. power grid. It was therefore recommended to add the standard UL 1741, which is the 

Standard for Inverters, Converters, Controllers and Interconnection System Equipment for Use 

With Distributed Energy Resources for inverters for U.S.-based installations. 

A-14

Standards addressed: 

• Add: NFPA 2001, “clean agent”/inert-gas fire suppression standard

• Add: API RP 14C 

• Add: DNV GL ST 145, for passive/active suppression 

• Add: NFPA 16, for water-based foam systems.
41 

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The following question arose during the discussion: Would UPS systems be included in this

category, or do DC UPS systems fall under this concern, within the substation? One participant 

recommended that UPS systems not be included in this category. Instead, it was recommended 

that UPS systems be addressed in the utilities and support systems, as they would be used to keep 

the control and communication systems functional during a brief power outage.

5.6 B. Safety Procedures

B-1 Working on or Near Live Equipment

The substation group agreed that this topic was fully covered by NFPA 70E and OSHA 29 CFR

§ 1910 Subparts R, S. 

B-2 Personal Protective Equipment

The group agreed that the American Society of Testing Materials (ASTM) F1506 provides the 

best reference for PPE requirements, and generally aligns with NFPA and OSHA standards, as 

listed in the corresponding recommended standards textbox (B-2). The group did not address 

whether or not NFPA 70B applies to PPE, or if this standard is only relevant to O&M. 

B-3 Lockout/Tagout

The substation group agreed that lockout/tagout is applicable for all voltages. There was 

consensus that the developer must define the lockout/tagout procedure and criteria within their 

design specifications, as these approaches can vary for different equipment.

A-15

Standards addressed: 

• Add: UL 1741: Standard for Inverters, Converters, Controllers and Interconnection 

System Equipment for Use With Distributed Energy Resources. 

B-2

Standards addressed: 

• Recommended standards: ASTM F1506, NFPA 70E, OSHA 29 CFR § 1910.137. 

B-1

Standards addressed: 

• Recommended standards: NFPA 70E, OSHA 29 CFR § 1910, Subparts R, S. 
42 

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One participant recommended that that the IEC-based electrical equipment highlighted in the 

wind turbine section be provided with specific provisions for lockout/tagout that are compatible 

with the OSHA-mandated lockout/tagout requirements. 

B-4 Equipment Guarding (Energized Component)

The group agreed that USCG rules do not require guardrails for fixed structures. The group also 

agreed that guarding for high-voltage GIS equipment is unnecessary. There was agreement that 

only energized equipment must be guarded. This is different than space around equipment, 

which is focused on permitting ingress and egress. 

The group agreed to exclude floating wind energy substations from this conversation, which will 

be addressed by other standards initiatives. 

It remains an open issue whether or not USCG IEEE C2 Sub.J is applicable, although this issue 

may not represent the most pertinent issue(s) for this topic. 

5.7 C. Reliability Design

C-1 Safety (Testing/Fit for Purpose) – Acceptance Testing

The substation group agreed that the question of safety acceptance testing should be deferred to 

the CVA. It was agreed that each OEM creates its own pre and postenergization inspection and 

test protocols. Additionally, developers have their own commissioning and execution plans. 

The group further agreed that BSEE should recommend that developers test electrical equipment 

before energizing, but observed that this testing can vary by project, developer, or manufacturer. 

Proof-of-concept testing should be conducted by the OEM. The group generally agreed that 

commissioning activities are project- and equipment-manufacturer/type specific. The 

ANSI/NETA acceptance testing specifications (ATS) should still be considered for 

recommended guidelines. 

B-3

Standards addressed: 

• Recommended standards: NFPA 70E 

• Specify: OSHA 29 CFR § 1910 is general, whereas OSHA 29 CFR § 1910.147 is specific 

to lockout/tagout. 

B-4

Standards addressed: 

• Add: IEEE C2 (NESC)

• Add: API RP 14F. 
43 

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Generally, it is recommended that the industry move away from IEC 61400-22 and adopt IECRE 

OD-501 and -502. Work has been done so that it can result in certificates of higher quality and 

also allows for better mutual recognition. Many turbine suppliers have already adopted the 

IECRE system, and it is expected that in the future most offshore turbines will be required to 

have IECRE certificates. IEC 61400-22 is an outdated standard and is no longer recognized by 

IEC or the U.S. National Committee. IECRE OD-501 and –502 are referenced in both the 

turbines and substations sections.

C-2 Wiring Methods High Voltage

The substations group did not discuss this topic in depth. One participant commented that there 

are high-voltage cables used in the platform that are not submarine cables(e.g., between the GIS 

and transformer). It is recommended that these cables also be built and tested to IEC standards 

rather than the Insulated Cable Engineers Association (ICEA) to avoid creating unnecessary

IEC/ICEA interfaces that may require specialized IEC/ICEA cable joints and different types of 

cable terminations.

Another participant commented that European designs typically use plug-in termination for highvoltage cables (e.g., Pfisterer Connex). These can be dry type or oil-immersed. There are no 

equivalent U.S. standards for these types of terminations above 52 kV. It was recommended to 

allow the use of plug-in terminations (e.g., Pfisterer Connex) according to relevant IEC/EN 

standards. 

C-3 Wiring Methods Medium Voltage

The substations group did not discuss this topic in depth but agreed to include API RP 14F and 

NEC NFPA 70 to the list of relevant standards. 

C-3

Standards addressed: 

• Add: API RP 14F 

• Add: NEC NFPA 70.

C-1

Standards addressed:

• Remove: IEC 61400-22 

• Remove: BS EN 61400-22 

• Add: IECRE OD-501 and -502 

• Add: CIGRE B3.26 

• Add: ANSI/NETA ATS. 

C-2

No standards were explicitly addressed, discussion only. 
44 

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C-4 Wiring Methods Low Voltage

The substations group concluded that NFPA 70 is the recommended standard. The group agreed 

that additional information would be needed to properly address the topic of low-voltage wiring 

methods; either a submarine cable or interconnection cable.

The question arose during the workshop as to what a low-voltage submarine cable is. One 

participant commented that there is no such cable. They noted that [submarine cables] are 

intended for power transmission over some distance and can be available in medium-voltage or 

high-voltage applications. Rather, this participant suggested that low-voltage wiring methods 

specifically apply to the substation facility, with a focus on marine applications. Therefore, they 

recommend that API RP 14 F be added to the current reference to the NEC (NFPA 70) to be 

used for the recommended wiring methods for low-voltage applications for offshore facilities in 

the United States. This was added to address specific requirements for marine use and exposure 

to corrosive, salt-laden environments. 

C-5 Wiring Methods

The group felt it necessary to discuss and clarify the term “marine shipboard cable.” The group 

questioned whether this term refers to actual “shipboard” cables (a special designation of cable), 

or if it was referencing any kinds of cables that are found onboard an offshore wind substation 

platform. The group agreed that it is important to clarify that for substations, marine shipboard 

cables are not the only cables to be used. Therefore, the group suggested removing “shipboard 

cable” from both the standard category column, and from the NRTL certification column. It was 

noted that IEEE 1580 should be allowed for marine shipboard cable to be used without being 

installed in accordance with IEEE 45, as this could be a viable option for armored cables 

installed outside on the platform. Also, it was recommended by one participant that all types of 

armored cables be allowed to be installed in a cable tray. 

One participant recommended that “Type P cable” could replace “marine shipboard cable” in the 

category column of Table D-1, as this is the designation that is currently published in the 2020 

version of the NEC (NFPA 70) that refers to the same type of cable design suitable for marinetype environments. Another participant suggested allowing all types of armored cable to be 

installed in a cable tray.

The question arose during the discussion to clarify the suggested wiring methods. One 

participant commented that in the United States, the term “wiring methods” refers to 

interconnection cables. Another participant suggested the following recommendations regarding 

the conflicting low-voltage wire coloring schemes within using the standards listed in the 

upcoming text box. The following color scheme should be used: protective ground (equipment 

grounding conductor) cables should be green or green with yellow strips. Neutral cables should 

be white or light grey. Both of these requirements are from NFPA 70. For DC cables, +ve should 

C-4

Standards addressed: 

• Recommended standards: NFPA 70 (NEC)

• Add: API RP 14F. 
45 

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be red and -ve should be black. All other cables coloring (i.e., L1, L2, and L3 for 480 V/277 V 

and 208 V/120 V, control wiring) should be at the discretion of the designer provided a 

consistent approach is used. 

Another participant suggested to add low-smoke or halogen-free U.S. standards that align with 

the European ones, as low-smoke/low-halogen cables are preferred for an offshore substation. 

These standards are listed in the following text box. 

C-6 Cable Flammability Testing

There was consensus that cables are typically “flame retardant.” The group found it necessary to 

distinguish between fire-rated cables, fire-retardant cables, and fire-resistant cables. One 

participant commented that submarine cables will not have flammability standards applied but 

will utilize external coverings applied at the substations to provide the degree of protection 

required by the standards. Another participant commented that the standards referenced within 

API RP 14 F will provide distinctions between the terms fire-rated, fire-retardant, and fireresistant. 

It was recommended by one participant to add IEC 60331-1, -2, and -21 standards to 

accommodate a broader range of potential cable vendors. 

Additionally, it was agreed that both the substations group and the cables group would address 

the issue of cable flammability testing. 

C-5

Standards addressed: 

• NFPA 70 and API RP 14F: wiring methods beyond marine shipboard cables 

• Add: NFPA 70: allows the manufacturer to choose their own kind of wiring method 

• Add: API RP 14F: wiring practices for offshore 

• Add: IEC 60331-1, -2, -21 for fire resistivity

• Add: IEC 60754-1 and –2: halogen-free standard

• Add: IEC 61034-1 and -2: low-smoke standard 

• Remove from category name column: “marine shipboard cable”

• Remove from certification column: “Cables should be listed as a marine shipboard cable

by a NRTL”

• All other standards listed are for marine shipboard cables. 
46 

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C-7 Harmonics

The group agreed that the developer must address any harmonics issues within the offshore 

substation, whereas the grid operator must address onshore substation harmonics. 

C-9 Uninterruptable Power Supplies

The group agreed that UPS are a combination of DC and AC components. It was also agreed that 

it is necessary to establish a bridging system through the start cycle, and to establish power from 

the diesel system. It was noted that UL 62109-1 is a USCG requirement for Safety of Life at Sea.

C-14 Surge Protection/Suppression Component 

The group discussed switching operation surges and agreed that the IEEE C37 90.1 standard 

should be added. 

C-7

Standards addressed: 

• Recommended standards: IEEE 519 

o Applies at the point of interconnection 

o This standard is sufficient; not required inside of substation, but just at the 

point of common coupling. 

C-6

Standards addressed: 

• Add: API RP 14F 

o Reveals which applications require low-smoke, low-halogen cables

o Defines where fire-related cables should be used 

o Defines which kind of fire-related cables should be used 

• Add: IEC 60331-1, -2, and -21. 

C-9

Standards addressed: 

• Add: IEEE 946 

• Add: IEEE 44 or 484. 
47 

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C-19 Lighting

The group recommended removing all of the information in the last column; the developer 

should define this, as it is not relevant to electrical safety. 

It was recommended by one participant that lighting details for boat landings may not be 

addressed within these standards. It was recommended that the boat should provide emergency 

egress illumination without needing permanently installed lighting along egress ladders and boat 

landings. 

C-20 Illumination Levels for Emergency Evacuation

The substation group briefly discussed this topic and recommended API RP 14F to address it. 

C-21 Emergency and Standby Power Systems

The group discussed how to define “emergency power systems.” There was consensus that usage 

of the term “emergency power” may trigger certain USCG regulatory requirements. The group 

instead recommended using the terms “standby” or “essential” power systems and added API RP 

14F. 

C-20

Standards addressed: 

• Add: API RP 14F.

C-21

Standards addressed: 

• Add: API RP 14F.

C-19

Standards addressed: 

• Recommended standards: IEEE C2 (NESC)

• Add: API RP 14F: minimal lighting levels for offshore locations, included servicing. 

C-14

Standards addressed: 

• Add: IEEE C37 90.1. 
48 

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C-22 – Power Sockets and Plugs

The group agreed that the listed standards are acceptable. It was recommended to remove 

“Receptacle NEMA 4x protection” verbiage in the table’s certification column. 

It was recommended by one participant to add the NEC (NFPA 70) and API RP 14 F to address 

the selection and installation for receptacles for offshore wind facilities. This would also cover 

the requirements for GFCI protection of these devices depending on their location and type of 

service.

C-23 Cable Trays

The group discussed the different materialsaluminum, stainless steel, and fiberglass―used to 

manufacture cable trays. There was consensus that the standards listed appropriately address the 

various materials used to create cable trays.

One participant recommended API RP 14 F for the design and installation of cable tray systems 

for offshore wind facilities in the United States because this standard covers the sizing, type, 

placement, and installation methods for cable tray systems to be used in an offshore marine 

environment. 

C-24 Cable Cleats for Electrical Installations

The group agreed that there was no manufacturer stipulation on this topic, and that the cable 

group should address it. 

During the review of this document, a participant from the cables group commented that the 

group is addressing this topic only in relation to the clamping of the cables going to the first GIS 

connection. It was recommended that the clamps be tested according to IEC 61914 “Cable cleats 

for electrical installations” and spacing of clamps should be specified by cable manufacturer 

based in installation parameters. This international standard specifies requirements and tests for 

cable cleats and intermediate restraints used for securing cable in electrical installations. Cable 

cleats provide resistance to electromechanical forces where declared. This standard includes 

cable cleats that rely on a mounting surface specified by the manufacturer for axial and/or lateral 

retention of cables. 

C-23

Standards addressed: 

• UL 2277: construction specifications 

• Add: API RP 14F.

C-22

Standards addressed: 

• Add: NEC (NFPA 70)

• Add: API RP 14F.
49 

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C-25 Cathodic Protection

The substation group agreed that cathodic protection is a developer-implemented corrosion 

mitigation technique. 

C-26 Grounding and Bonding

This substation group agreed to add the standards API RP 14F , IEEE 837, and IEEE 80. 

General Comments and Recommendations

The substation breakout group discussions revealed that many of the identified standards pertain 

to the design of the substation itself. This was a common theme throughout the group discussion, 

because substations are generally individually designed to suit local site conditions. Accordingly, 

a developer’s specifications tend to more heavily influence substation design than does an 

electrical safety perspective. For example, the lengthy discussion of arc flash/arc blast boundary 

ultimately resulted in the need for design specifications to further clarify the applicable 

standards. 

In general, the U.S.-based IEEE or ANSI standards were considered to be defaults in many 

instances. When a U.S. standard was not available, IEC or other international standards were 

incorporated. This leads to the overarching question of how standards should be interpreted for 

worker training to ensure safety. Participants expressed different viewpoints regarding workforce 

utilization. Some companies use the same technicians to service on and offshore equipment, 

whereas others have separate specialized land-based and offshore workforces. A prescriptive 

standard may not be required in these instances, as this is more a question of operational strategy. 

Additionally, it was recommended to not use the subjective low/medium/high descriptions for 

voltage; rather, voltage classes should be specifically stated in accordance with the NEC 

definitions, which was stated in the general key findings (Section 2.1). Across the board, greater 

C-25

Standards addressed: 

• Recommended standards: NACE RP-01 

• NACE RP-01: corrosion protection. 

C-26

Standards addressed: 

• Recommended standards: UL 467 

• UL 467: grounding and bonding equipment 

• Add: API RP 14F (covers grounding for offshore) 

• Add: IEEE 837 

• Add: IEEE 80.
50 

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specificity should reduce confusion and miscommunication, leading to safer offshore substations. 
51 

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6 Assessment of Relevant Electrical Safety Standards 

for Submarine Cables

Electrical safety standards for subsea cables are considered in the scope of work being completed 

by the AWEA OCRP Working Group (WG) 5, which is currently developing its 

recommendations. The cables breakout group included members of WG 5, as well as 

representation from submarine cable manufacturers, offshore wind project developers and 

operators, certification organizations, and BSEE. The organization of this section is intended to 

be consistent with the draft outline of the OCRP WG 5 document, which will have a similar 

structure.

6.1 Scope

The cables breakout group (hereinafter “the group”) focused on array and export cables, with the 

scope defined in line with the WG 5 scope. Array cables are defined as extending between the 

terminations of the offshore wind facility structures, typically from the wind turbine to the 

substation. For export cables, the scope covers the cable between the termination on the offshore 

wind facility structure and where the submarine cable either terminates or transitions to a land 

cable design in a transition joint (splice). 

Voltages for an offshore wind power plant array and export cables are generally 35 kV and 

above. In Table D-1, array and export cables primarily fall in the “high-voltage” category, 

although standards listed under “medium voltage” may also be applicable to array or export 

cables with ratings at the lower end of the range. Although Europe and China are beginning to 

adopt HVDC systems for wind farms located far from shore, workshop participants do not 

anticipate any HVDC installations in the United States prior to the completion of the AWEA 

OCRP update that is scheduled for publication in 2021. Accordingly, standards for HVDC cables 

were not considered in detail during this workshop. 

Electrical safety standards were discussed primarily in the context of reliability. There was broad 

consensus that a well-designed and properly installed cable should—barring external factors 

such as an anchor strike—not require any human interaction for the remainder of its lifetime. 

Ensuring reliability and minimizing the need for repairs is the best method for assuring safety. 

The other main approach to safety is having a repair plan in place in advance, in which all of the 

relevant standards and best practices are considered before they are urgently needed.

DNV GL-ST-0359 (Subsea power cables for wind power plants) and DNV GL-ST-0360 (Subsea 

power cables in shallow water) provide useful information relevant to submarine cables in all 

stages of the offshore wind plant lifecycle; however, they are recommended practices rather than 

U.S. or internationally recognized standards. 

6.2 Submarine Cable Route Planning

Guidance from the AWEA OCRP 2012 recommended practice document remains relevant for 

cable route planning. A cable route should be planned based on data from the site 

characterization study and a desktop study of the seabed between the project site and proposed 
52 

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cable landing point. The North American Submarine Cable Association1 and the International 

Cable Protection Committee2

 provide resources for identifying submarine cable locations and 

ownership. If other cables or pipelines are found to intersect the proposed route, the developer 

should, before construction begins, contact the owners of those facilities to negotiate the 

appropriate legal agreements regarding crossing and proximity. Documents that provide 

guidance for route surveys include: 

• BOEM’s guidelines for providing geological and geophysical hazards and archaeological 

information pursuant to 30 CFR § 585 

• Minimum requirements for the foundation of offshore wind turbines and power cable route 

burial assessments; Bundesamt für Seeschifffahrt und Hydrographie (Federal Maritime and 

Hydrographic Agency of Germany), August 2003 

• International Cable Protection Committee Recommendation No. 3. Issue 9A: criteria to be 

applied to proposed crossings between submarine telecommunications cables and 

pipelines/power cables; Issue 2A: minimum technical requirements for a desktop study. 

6.3 Submarine Cable Design, Manufacturing, and Testing

The application of standards to the design, manufacturing, and testing of export and array cables 

for offshore wind power plants is complicated by the absence of comprehensive standards for 

submarine power cables. Standards suitable for cables installed on land do not cover the 

additional requirements for submarine cables used in offshore wind systems, which typically 

include multiple cores, optical fiber, bedding, armor, and an outer jacket. IEC 63026 (Submarine 

power cables with extruded insulation and their accessories for rated voltages from 6 kV up to 60 

kV - Test methods and requirements) is the only internationally recognized standard covering 

both mechanical and electrical testing specifically adapted for submarine cable systems. 

In the absence of standards specific to high-voltage subsea cables, the recommended practice is 

to follow standards for high-voltage land-based cables in combination with the guidance 

provided in CIGRE TB 490 (Recommendations for testing of long AC submarine cables with 

extruded insulation for system voltage above 30 to 500 kV) and CIGRE TB 623 

(Recommendations for mechanical testing of submarine cables). CIGRE TB 496 

(Recommendations for testing HVDC extruded cable systems for power transmission at a rated 

voltage up to 500 kV) provides guidance for HVDC cables. Examples of acceptable 

combinations of standards include: 

• IEC 60840 (Power cables with extruded insulation and their accessories for rated voltages 

above 30 kV up to 150 kV – Test methods and requirements) and CIGRE TB 490 

• IEC 62067 (Power cables with extruded insulation and their accessories for rated voltages 

above 150 kV up to 500 kV – Test methods and requirements) and CIGRE TB 490. 

Participants in the cables group expressed different views regarding non-IEC standards. Some 

participants recommended using only IEC standards, whereas others believed that other 

standards should be allowed. A broad conclusion from the discussion was that if a relevant party, 

1 https://www.n-a-s-c-a.org/ 2 https://www.iscpc.org
53 

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such as a developer or interconnecting utility, requests cable core insulation wall thickness to be 

in compliance with standards issued by another SDO (such as the Association of Edison 

Illuminating Companies [AEIC] or ICEA), that could be acceptable as long as the cable system

is type tested and prequalified following the procedures described in the relevant IEC and 

CIGRE standards documents. The added testing and potential increase in cable mass would 

likely increase costs and lead time associated with cable installation.

CIGRE TB 722 (Recommendations for additional testing for submarine cables from 6 KV up to 

60 kV) provides guidance on recommended testing for wet and semiwet cable designs. 

Prequalification and type testing of a cable system for a given voltage can also qualify a lowervoltage cable system of the same design, as described in IEC 60840 and IEC 62067. 

For the calculation of current ratings, IEC 60287 (Electric cables - Calculation of the continuous 

current rating of cables) is recommended. The method and process for ampacity calculation is 

explained and examples of the calculation process are given in the EPRI Underground 

Transmission Systems Reference Book—2016 Edition, Chapter 11. If the cable will be 

dynamically rated, site-specific data on wind speeds and proposed turbine capacity will be 

required to calculate the appropriate current rating. A conference paper, “CIGRE B1-303_2016: 

Systematic Description of Dynamic Load for Cables for Offshore Wind Farms. Method and 

Experience” outlines the methodology for reducing that data to calculate the current rating for 

dynamic loading. Appendix D4 in CIGRE TB 610 (Offshore generation cable connections) also 

provides information on dynamic loading calculations. 

C-2 (Wiring Methods High Voltage)

Submarine cable standards addressed:

• Recommended standards: 

o IEC 63026 

o Not specific to subsea cable, should be used in conjunction with CIGRE 

documents below: IEC 62067, IEC 60840, and IEC 60228 

o DNVGL-ST-0359 

o CIGRE TB 490, CIGRE TB 496, CIGRE TB 610, CIGRE TB 623, and 

CIGRE TB 784. 

• Other relevant standards (not specific to subsea cable; should be used in conjunction with 

CIGRE documents mentioned earlier): 

o AEIC CS9, ICEA S-108-720 

o IEEE C2 (NESC), IEEE 404, and IEEE 1300. 
54 

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6.4 Submarine Cable Installation

The installation process presents the highest risk for human error to impact cable performance. 

Careful planning and qualified personnel can mitigate some of the risks inherent to installation. 

Specific standards for cable installation are provided in the AWEA OCRP 2012. 

Guidance for submarine cable joints and terminations can be found in: 

• CIGRE TB 490 and CIGRE TB 610 

• IEC 60859 (Cable Connections for Gas-Insulated Metal-Enclosed Switchgear for Rated 

Voltages of 72.5 kV and Above – Fluid-filled and Extruded Insulation Cables – Fluid-Filled 

and Dry Type Cable - Terminations). Please note, however, that this standard has been 

withdrawn and replaced by IEC 62271-209 (High-voltage switchgear and controlgear - Part 

209: Cable connections for gas-insulated metal-enclosed switchgear for rated voltages above 

52 kV - Fluid-filled and extruded insulation cables - Fluid-filled and dry-type cableterminations)

• IEEE 48 (Standard for Test Procedures and Requirements for Alternating-Current Cable 

Terminations Used on Shielded Cables Having Laminated Insulation Rated 2.5 kV through 

765 kV or Extruded Insulation Rated 2.5 kV through 500 kV) 

• IEEE 404 (Standard for Extruded and Laminated Dielectric Shielded Cable Joints Rated 2.5 

kV to 500 kV); one participant stated that this standard is incompatible with the IEC/CIGRE 

submarine cable standards

• IEEE 1300 (Guide for Cable Connections for Gas-Insulated Substations); one participant 

noted that this is a copy of the IEC 60859 standard

• CIGRE TB 784 (Standard design of a common, dry type plug-in interface for GIS and power 

cables up to 145 kV) 

• Joining two different types of cable: CIGRE TB 303 (Revision of qualification procedures 

for high voltage and extra high voltage AC extruded underground cable systems). 

C-12 (Cable Testing)

Standards addressed: 

• Recommended standards: 

o IEC 60230, IEC 60229, IEC 60287, and IEC 60811-501 

o CIGRE TB 303, CIGRE TB 490, CIGRE TB 623, and CIGRE TB 722 

• Other relevant standards (not specific to subsea cable): 

o AEIC CS8 and AEIC CS9

o ICEA P-32-382, ICEA P-45-482, ICEA S-94-649, ICEA T-24-380, ICEA T31-610, ICEA T-32-645, and ICEA T-34-664 

o IEEE 48.
55 

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6.5 Submarine Cable Flammability

Although cable flammability is not a concern underwater, it should be considered for the portion 

of the cable that enters a wind turbine or substation and is exposed to air. The level of fire 

protection required depends on the classification of the offshore structure (e.g., manned, 

unmanned, not normally manned) and the corresponding risk that personnel could be exposed to 

a fire. CIGRE TB 720 (Fire issues for insulated cables in air) provides guidance on the selection 

of materials for fire safety as well as fire suppression techniques. Other standards relevant to 

cable flammability testing are listed under item C-6 in Table D-1. 

Submarine cables will not be supplied with a coating over the individual cable cores that is flame 

resistant or retardant. Where the cable cores are broken out of the armor protection after the 

armor hang-off, the cable cores should be either placed in a metallic, nonmagnetic cable raceway 

or, alternately, continuously covered with a flame-retardant tape or covering material from the 

hang-off to the cable termination to protect the cable core jackets from flames and to contain a 

cable jacket fire. See CIGRE TB 720 for recommendations to protect cable. If halogen gas or 

smoke is of concern, the raceway or covering should be designed to route the gas or smoke away 

from the areas of concern and to vent to a safe exterior location in the case of a cable fire. 

Locating and/or pulling the cables into individual conduits or pipes will most likely not be 

practical and could be more of a safety hazard to the crew trying to pull the cables into pipes. 

API RP 14F was identified during the workshop as a potential source of information for 

determining the classification of the offshore structure. When examined in detail, however, the 

standard’s references to umbilical cables are specific to the oil and gas industry and do not apply 

to offshore wind array and export cables. 

6.6 Operation and Maintenance

Normal operation of submarine power cables should not require active intervention. Periodic 

inspection along the cable route should be carried out to detect any changes in the depth of 

buried cables—in particular, exposure as a result of scour, subsidence, sand waves, and so on—

or mechanical damage to the cable. Cables may also be designed with integrated fiber optic 

sensors that can detect changes in burial depth, strain, or temperature along the cable. If a cable 

becomes exposed, reburial or additional protection may be needed. Initial cable characterization 

using a method such as optical time domain reflectometry can provide a basis for comparison if a 

fault occurs.

Advance preparation of a repair plan is strongly recommended. After a fault has occurred, repair 

planning becomes time critical and mistakes or omissions that compromise safety are more 

likely. Guidance for developing a repair plan can be found in CIGRE TB 773 (Fault location on 

C-6 (Cable flammability testing)

Standards addressed: 

• Recommended standards: 

o CIGRE TB 720.
56 

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land and submarine links (AC & DC)). The information in IEEE 1234 (Guide for Fault-Locating 

Techniques on Shielded Power Cable Systems) is similar, but its focus is primarily on power 

cables installed on land. Key elements of a repair plan include:

• Obtaining spare parts and cable 

• Storing spare stock appropriately so that it achieves its expected shelf life and replacing it as 

needed

• Identifying local contractors with expertise and equipment available for cable locating, fault 

locating, and cable repair

• Establishing agreements with identified contractors to provide timely response and repair for 

any cable problem that may arise

• Specifying a safe operating plan for repair operations. 

The safe operating plan should cover shutdown procedures, lockout/tagout procedures and 

communication, and induced voltage procedures. Acceptable standards for safe working 

practices near subsea cables are listed under item B-5 in Table D-1. IEEE 1727 (Guide for 

Working Procedures on Underground Transmission Circuits with Induced Voltage) and CIGRE 

B1-115_2018 (Safe Work on HV Extruded Insulation Cable Systems under Induced Voltages), 

which provide guidance on safety for working on a deenergized line in proximity to an energized 

line. Safety during diving operations is covered by the Association of Diving Contractors 

International Consensus Standards for Commercial Diving and Underwater Operations (6th Ed., 

Rev. 6.3, 2019) and the International Marine Contractors Association (IMCA) international code 

of practice for offshore diving (IMCA D 014 Rev. 2.1, 2019). 

6.7 Decommissioning

Current guidance from BOEM in 30 CFR § 585 requires developers to include the cost of 

decommissioning (i.e., removing the cable and returning the site to its original condition, subject 

to an environmental impact assessment). Because of the disturbance to the seabed when 

removing a buried cable, the conclusion of the environmental impact assessment may be a 

recommendation to leave the cables in situ. 

B-5 (Work on Submarine Cables)

Standards addressed: 

• Recommended standards: 

o IEC 60204 

o CIGRE TB 773

o IEEE 1727 and IEEE 1234.
57 

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7 Next Steps

Understanding the design and safety implications of the various proven European design 

methods and existing U.S. codes and standards is essential for the maturation of the U.S. 

offshore wind industry. The Offshore Wind Electrical Safety Standards Harmonization 

Workshop held on February 11–12, 2020, at NREL’s Flatirons Campus near Boulder, Colorado, 

and this report, which documents the proceedings of the workshop, represent a major step in the 

process to implement safe design and safety practices for offshore wind facilities on the U.S. 

Outer Continental Shelf. 

This publication can now serve as a near-term reference to inform project design and approvals, 

thereby leveraging these workshop proceedings to help inform U.S. industry-recommended 

practices, which are under development by the AWEA Wind Technical Standards subcommittee. 

The primary next step is to complete the current AWEA/ANSI U.S. offshore wind standards 

initiative and publish a suite of five offshore recommended practices documents. A formal 

AWEA/ANSI approval process for these recommended practices includes vital procedural 

safeguards that will allow BOEM/BSEE to reference them in future revisions to 30 CFR § 585, 

and, if appropriate, explicitly quote them in regulations. 

In the interim period, we recommend that work continue to update Table D-1 to reflect the most 

current thinking, as there was not enough time during the workshop to complete this discussion. 

This could be accomplished through additional workshops held while the more formal OCRP 

recommendations are being finalized. This would allow BOEM/BSEE to engage individually 

with industry representatives to gather more candid information. 

Additionally, BOEM/BSEE could engage directly with the land-based wind community and 

NRTLs to incorporate their experience integrating the international land-based wind industry 

into the U.S. market. 

Finally, a key component to the safety of workers employed during the construction and 

operation of U.S. offshore wind facilities will be proper workforce training. It is essential that the 

U.S. industry develop workforce training and health and safety protocols that integrate with the 

electrical safety standards discussed in this report, and which comply with and facilitate the 

BOEM/BSEE safety management system requirements. These activities should be initiated 

immediately and proceed in parallel with the development of the OCRP recommended practices. 
58 

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8 References

American Wind Energy Association. 2012. AWEA Offshore Compliance Recommended 

Practices. Recommended Practices for Design, Deployment, and Operation of Offshore Wind 

Turbines in the United States. https://offshorewindhub.org/sites/default/files/resources/awea_9-

16-2012_oswrecommendedpractices.pdf. 

Electric Power Research Institute. 2016. EPRI Underground Transmission Systems Reference 

Book: 2016, Chapter 11 

CIGRE. 2016. Systematic description of dynamic load for cables for offshore wind farms. 

Method and experience. CIGRE B1-303_2016. https://e-cigre.org/publication/B1-303_2016 

CIGRE. 2018. Safe Work on HV Extruded insulation Cable Systems under induced Voltages. 

CIGRE B1-115_2018. https://e-cigre.org/publication/SESSION2018_B1-115. 

 
59 

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9 List of Primary Standards

This list represents the standards that are referred to in the body of the report but is not a 

comprehensive list of the standards in Table D-1. 

Table 1. List of Primary Standards Referenced in Report

Standards # Topic Covered

AEIC CS9 Specification for extruded insulation power cables and their accessories 

rated above 46 kV through 345 kVAC

ANSI/NETA 

ATS

Standard for Acceptance Testing Specifications for Electrical Power 

Equipment and Systems

ANSI C57 

Series

Standard for Low-Voltage Transformers and Reactors

API RP 14C Analysis, Design, Installation, and Testing of Basic Surface Safety Systems 

for Offshore Production Platforms; 30 CFR 250.1628(c) 

API RP 14F Design and Installation of Electrical Systems for Offshore Production 

Platforms; 30 CFR 250.114(c)

ASTM F1506 Standard Performance Specification for Flame Resistant and Electric Arc 

Rated Protective Clothing Worn by Workers Exposed to Flames and Electric 

Arcs

AWEA OCRP 

2012

AWEA Offshore Compliance Recommended Practices 2012

CIGRE B1-

115_2018

“Safe Work on HV Extruded insulation Cable Systems under induced 

Voltages” 

CIGRE B1-

303_2016

“Systematic description of dynamic load for cables for offshore wind farms. 

Method and experience” 

CIGRE B3.26 Guidelines for the Design and Construction of AC Offshore Wind Farms

CIGRE TB 303 Revision of qualification procedures for high-voltage and extra-high-voltage 

AC extruded underground cable systems

CIGRE TB 490 Recommendations for testing of long AC submarine cables with extruded 

insulation for system voltage above 30 (36) to 500 (550) kV
60 

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Standards # Topic Covered

CIGRE TB 496 Recommendations for Testing DC Extruded Cable Systems for Power 

Transmission at a Rated Voltage up to 500 kV

CIGRE TB 610 Offshore Generation Cable Connections

CIGRE TB 623 Recommendations for Mechanical Testing of Submarine Cables

CIGRE TB 720 Fire issues for insulated cables in air

CIGRE TB 722 Recommendations for additional testing for submarine cables from 6 KV up 

to 60 KV

CIGRE TB 773 Fault location on land and submarine links (AC and DC)

CIGRE TB 784 Standard design of a common, dry-type plug-in interface for GIS and power 

cables up to 145 kV

CAN/CSAC22.2 No. 272 Wind Turbine Electrical Systems

CSA C22.2 CSA C22.2 No. 0.4 - Bonding of Electrical Equipment

CSA C22.2 CSA C22.2 No. 41 - Grounding and Bonding Equipment

CSA SPE-1000-

13 

Model Code for the field evaluation of electrical equipment

CSA Z462 Workplace Electrical Safety (Based on NFPA 70E)

DNVGL-ST0359Subsea power cables for wind power plants

DNVGL-ST0360Subsea power cables in shallow water

DNVGL-ST-145 Offshore substations

EN 61034-2 Measurement of smoke density of electric cables burning under defined 

conditions - Part 2: Test procedure and requirements

ICEA S-108-720 Standard for Extruded Insulation Power Cables Rated Above 46 Through 

500 KV AC
61 

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Standards # Topic Covered

IEC 60034 

series

Rotating electrical machines 

IEC 60204-1 Safety of machinery - Electrical equipment of machines - Part 1: General 

requirements

IEC 60204-11 Safety of machinery - Electrical equipment of machines - Part 11: 

Requirements for equipment for voltages above 1,000 V AC or 1,500 V DC 

and not exceeding 36 kV

IEC 60287 Electric cables - Calculation of the current rating

IEC 60364 Low-voltage electrical installations 

IEC 60364-7-

729 

Low-voltage electrical installations - Part 7-729: Requirements for special 

installations or locations - Operating or maintenance gangways

IEC 60502-2 Power cables with extruded insulation and their accessories for rated 

voltages from 1 kV (Um = 1,2 kV) up to 30 kV (Um = 36 kV) – Part 2: Cables 

for rated voltages from 6 kV (Um = 7,2 kV) up to 30 kV (Um = 36 kV)

IEC 60840 Power cables with extruded insulation and their accessories for rated 

voltages above 30 kV (Um = 36 kV) up to 150 kV (Um = 170 kV) – Test 

methods and requirements

IEC 60909-0 Short-circuit currents in three-phase a.c. systems - Part 0: Calculation of 

currents

IEC 61034-2-

2005

Measurement of smoke density of cables burning under defined conditions 

- Part 2: Test procedure and requirements

IEC 61039 Classification of insulating liquids

IEC 61400-1 Wind energy generation systems – Part 1: Design requirements

IEC 61400-3-1 Wind energy generation systems – Part 3-1: Design requirements for fixed 

offshore wind turbines

IEC 61400-3-2 Wind energy generation systems – Part 3-2: Design requirements for 

floating offshore wind turbines

IEC 61482-2 European equivalent to ASTM F1506 for the thermal hazards of an arc 

flash. The standard includes requirements for material testing and 

additional information for garments constructed from compliant materials. 
62 

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Standards # Topic Covered

This is required for selling garments for arc flash protection in the European 

Union. 

IEC 61936-1 Power installations exceeding 1 kV a.c. - Part 1: Common rules

IEC 61914 Cable Cleats for Electrical Installations

IEC 62067 Power cables with extruded insulation and their accessories for rated 

voltages above 150 kV (Um = 170 kV) up to 500 kV (Um = 550 kV) – Test 

methods and requirements

IEC 62271-200 High-voltage switchgear and controlgear - Part 200: AC metal-enclosed 

switchgear and controlgear for rated voltages above 1 kV and up to and 

including 52 kV

IEC 62271-203 High-voltage switchgear and controlgear - Part 203: Gas-insulated metalenclosed switchgear for rated voltages above 52 kV

IEC 62477-1 Safety requirements for power electronic converter systems and 

equipment - Part 1: General

IEC 62477-2 Safety requirements for power electronic converter systems and 

equipment – Part 2: Power electronic converters from 1,000 V AC or 1,500 

V DC up to 36 kV AC or 54 kV DC

IEC 63026 Submarine power cables with extruded insulation and their accessories for 

rated voltages from 6 kV (Um = 7,2 kV) up to 60 kV (Um = 72,5 kV) - Test 

methods and requirements

IEC TR 61641 Enclosed low-voltage switchgear and controlgear assemblies - Guide for 

testing under conditions of arcing due to internal fault

IECRE OD-501 Type and component certification scheme

IECRE OD-502 Project certification scheme

IEEE C2 (NESC)

IEEE C37.20 Guide for low-voltage and medium-voltage arc gear

IEEE C37 90.1 Standard for Surge Withstand Capability (SWC) Tests for Relays and Relay 

Systems Associated with Electric Power Apparatus
63 

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Standards # Topic Covered

IEEE C37.122 Guide for Gas-Insulated Switchgear, specific to High Voltage

IEEE 1234 Guide for Fault-Locating Techniques on Shielded Power Cable Systems

IEEE 1300 Guide for Cable Connections for Gas-Insulated Substations

IEEE 1547 EEE Standard for Interconnection and Interoperability of Distributed Energy 

Resources with Associated Electric Power Systems Interfaces

IEEE 1584 IEEE Guide for Performing Arc Flash Hazard Calculations

IEEE 1727 Guide for Working Procedures on Underground Transmission Circuits with 

Induced Voltage

IEEE 404 Standard for Extruded and Laminated Dielectric Shielded Cable Joints Rated 

2.5 kV to 500 kV

IEEE 519 Standard for Point of Interconnection

IEEE 946 Recommended Practice for the Design of DC Auxiliary Power Systems for 

Generating Stations

IEEE 80 Guide for Safety in AC Substation Grounding

IEEE 837 Standard for Qualifying Permanent Connections Used in Substation 

Grounding

IEEE 44 (or 

484)

Recommended Practice for Installation Design and Installation of Vented 

Lead-Acid Batteries for Stationary Applications

ISO 12100 Safety of machinery – General principles for design – Risk assessment and 

risk reduction 

ISO 14122-1 Safety of machinery ― Permanent means of access to machinery ― Part 1: 

Choice of fixed means and general requirements of access

ISO 14122-4 Safety of machinery ― Permanent means of access to machinery ― Part 4: 

Fixed ladders

ISO 4413 Hydraulic fluid power — General rules and safety requirements for systems 

and their components

ISO 9001 Quality Management
64 

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Standards # Topic Covered

NACE RP-01 Corrosion Protection

NEMA 250 Enclosures for Electrical Equipment (1,000 Volts Maximum)

NEMA 

ANSI/IEC 

60529

Degrees of Protection Provided by Enclosures (IP Code) (Identical National 

Adoption)

NFPA 70 Standard for Electrical Safety in the Workplace, Chapter 1, Articles 100-130 

― Working on or near live equipment

NFPA 70B Recommended Practice for Electrical Equipment Maintenance

NFPA 70E Standard for Electrical Safety in the Workplace; Chapter 1, Articles 100-130 

― Working on or near live equipment

NFPA 79 Electrical Standard for Industrial Machinery

NFPA 780 Lightning Protection

NFPA 2001 Standard for Clean Agent/Inert Gas Fire Suppression

OSHA 29 CFR 

1910

Occupational Safety and Health Standards

OSHA 29 CFR 

1910 Subpart R

Special Industries

OSHA 29 CFR 

1910 Subpart S

Electrical

OSHA 29 CFR 

1910.23

Ladders

OSHA 29 CFR 

1910.137

Personal Protection Equipment

OSHA 29 CFR 

1910.147

Lockout/Tagout (LO/TO)

OSHA 29 CFR 

1910.269(h)

Electric Power Generation, Transmission, and Distribution ― Fixed ladders 

inside wind turbine towers
65 

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Standards # Topic Covered

OSHA 29 CFR 

1926.960 

Working on or near exposed energized parts (Construction)

UL 1004 series Standard for Rotating Electrical Machines

UL 1598 Luminaires

UL 467 Standard for Grounding and Bonding Equipment

UL 508 Standard for Industrial Control Equipment

UL 508A Standard for Industrial Control Panels

UL 508C Standard for Power Conversion Equipment

UL 2277 Standard for Construction Specifications

UL 6141 Standard for Wind Turbines Permitting Entry of Personnel

UL 61800-5-1 Standard for Adjustable Speed Electrical Power Drive Systems - Part 5-1: 

Safety Requirements – Electrical, Thermal and Energy 

UL 845 Standard for Motor Control

UL 1053 Standard for Safety Covering Ground Fault Protection

UL 1558 Standard for Metal-Enclosed Low-Voltage Power Circuit Breaker Switchgear
66 

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Appendix A. Attendee Information 

The table below provides a list of the attendees of the workshop who were the primary subject 

matter experts who guided the content of this report. 

Table A-1. Workshop Attendee List

Attendee Name Attendee Affiliation Break-Out Group 

Tom Buchal Independent Consultant Turbines

Edgar DeMeo Renewable Energy Consulting Services Turbines

Jens Brix Due Siemens Gamesa Renewable Energy Turbines

Albert Fisas GE Renewable Energy Turbines

Michelle Fogarty National Renewable Energy Laboratory

(NREL)

Turbines

Jonas Gertz Jensen Ørsted Turbines

Samuel H. Hawkins Siemens Gamesa Renewable Energy Turbines

Cheri Hunter Bureau of Safety and Environmental 

Enforcement (BSEE)

Turbines

Geoff Neild Vineyard Wind Turbines

Benjamin Palethorpe GE Renewable Energy Turbines

Christian Pohl Nexans Turbines

Christian Storbeck UL LLC Turbines

Jack Arruda Vineyard Wind Substations

Hendrik Berends RWE Renewables GmbH Substations

Brandon Burke Business Network for Offshore Wind Substations

Dave Burns Shell Substations

Emily Chambers Business Network for Offshore Wind Substations

Darryl Francois Bureau of Ocean Energy Management Substations

Jonathan Howie Energie Baden-Württemberg North 

America

Substations

Svein Johansen Equinor ASA Substations

Daniel Katz Ørsted Substations

Steven Kunsman ABB Substations

Nick Matone Burns & McDonnell Substations

Walt Musial NREL Substations
67 

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George Nichol GE Substations

Shane O’Sullivan Ørsted Substations

Juan Luis Paredes Ortiz Avangrid Substations

Stephan Schwab WSP Substations

Hongbiao Song GE Substations

Chloe Constant NREL Cables

Aubryn Cooperman NREL Cables

Joseph Cunningham Scottish Power/Avangrid Cables

Georg Engelmann Excipio Energy Cables

David Grassbaugh Ørsted Cables

Robert Hobson NKT Cables

Paul Knapp UL LLC Cables

Darin Lawton Burns & McDonnell Cables

Sabrina Morelli American Wind Energy Association Cables

David Nedorostek BSEE Cables

Maxime Toulotte Nexans Cables

Bill Wall LS Cable America Cables
68 

This report is available at no cost from the National Renewable Energy Laboratory at www.nrel.gov/publications.

Appendix B. Workshop Agendas 

Offshore Wind Electrical Safety Standards Harmonization Workshop

Tuesday, February 11 through Wednesday, February 12, 2020, at the Flatirons Campus

National Renewable Energy Laboratory (NREL)

18200 Highway 128 Boulder, CO 80303

Table B-1. Day 1 – Plenary Session (February 11, 2020)

Time Activity Speaker

8:00― 8:15 a.m. Flatirons Campus Arrival and CheckInNREL’s Flatirons Guard Gate

8:15― 8:45 a.m. Network/Lite Breakfast All

8:45― 9:00 a.m. Welcome, Meeting Objectives, and 

Introductions

Walt Musial (NREL

Cheri Hunter (Bureau of Safety and 

Environmental Enforcement [BSEE]) 

Darryl Francois (Bureau of Ocean Energy 

Management) 

9:00― 9:30 a.m. BSEE Perspective on U.S. Offshore 

Wind Electrical Safety Issues 

Cheri Hunter and David 

Nederostek/Darryl Francois 

(BSEE/BOEM) 

“Why are we here?” 

9:30―9:45 a.m. Overview of Offshore and Offshore 

Wind National Standards Initiative

Walt Musial (NREL)

9:45– 10:15 a.m. U.S. Offshore Wind Recommended 

Practices Status – Offshore 

Compliance Recommended Practice 

(OCRP)-1 

Albert Fisas (GE) Offshore Compliance 

Recommended Practices – Maintenance 

Team Delegate – “Status of OCRP-1”

10:15― 10:30 a.m. Break All

10:30―noon Session 1: Participant Presentations 

on Wind Plant Electrical Safety and 

Discussion 

Chair: Ed DeMeo―(NREL Consultant;

Workshop Chair)

Industry Speakers: 

• Samuel Hawkins (Siemens 

Gamesa) “OEM approach to 

electrical safety standards”

• Steven Kunsman (ABB) 

“Assessment of Secondary system 

issues including protection, 

control, automation, and cyber 

security”

• George Nichol (GE) “Offshore 

substations & equipment 

standards and lessons learned 
69 

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Time Activity Speaker

(gas-insulated switchgear and 

high-voltage DC)”

12:00― 1:00 p.m. Lunch (brought in) All

1:00 2:30 p.m. Session 2: Participant Presentations 

on Electrical Safety for Offshore 

Substations and Discussion

Chair: Ed DeMeo―Workshop Chair 

Industry Speakers: 

• Joseph Cunningham (Avangrid) 

“Assessment of U.S. Electrical 

Safety Regulations” 

• Hugo Avila (presented by Steven 

Kunsman) (ABB) “Assessment of 

High Voltage Primary Equipment 

Issues” 

• Steven Kunsman

(ABB)“BOEM/Moffat and Nichols 

Report”

2:30―2:45 p.m. Break All

2:45― 3:45 p.m. Session 3: Participant Presentations 

on Electrical Safety for Offshore 

Subsea Cables and Discussion

Chair: Ed DeMeo

Industry Speaker: 

• Bob Hobson (NKT Inc.) “Status of 

AWEA Working Group 5 

Recommended Practices for 

Submarine Cables”

3:45― 4:00 p.m. Break All

4:00― 5:00 p.m. Introduce Breakout Groups 

1) Turbines

2) Substations

3) Subsea Cables

Facilitation: Ed DeMeo; Breakout Groups 

Will Briefly Assemble and Work Out 

Reporting, Facilitation, and Protocols. 

Create a List of Key Issues to be Discussed 

on Day 2

5:00 p.m. Adjourn for the Day All

6:30 p.m. No-Host Dinner (TBD) Sign-Up at Registration
70 

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Table B-2. Day 2 – Breakout Group Discussions (February 12, 2020)

Time Activity Speaker

8:00―8:15 a.m. Flatirons Campus Arrival and 

Check-In

NREL’s Flatirons Guard Gate

8:15―8:45 a.m. Network/Lite Breakfast All

8:45―9:00 a.m. Review Plenary Breakout Group 

Objectives and Report-Out 

Guidance

Ed DeMeo (NREL Consultant)

9:00―9:15 a.m. Break and Assemble into 

Breakout Sessions

All

9:15―noon (Three) Facilitated Break-Out 

Sessions Meet Concurrently: 1) 

Turbines, 2) Substations, and 3) 

Subsea Cables

Breakout Facilitators Will 

Prescribe Their Own Coffee 

Breaks When Convenient

Notetakers Will be Assigned to 

Each Breakout Froup

Breakout Organizers: 

Facilitator/Chapter Lead

Turbines: Ed DeMeo/Michelle 

Fogarty

Substations: Brandon Burke/Emily 

Chambers

Subsea Cables: Chloe 

Constant/Aubryn Cooperman

12―1:00 p.m. Lunch (brought in) All

1:00―2:30 p.m. Breakout Groups Report-Out (30 

min Each with Q&A) 

Breakout Facilitators

Presentation: Hendrik Berends

(RWE) “Overview of Electrical Safety 

at RWE Windfarms during 

Construction and Commissioning” 

2:30―3:00 p.m. Wrap-UpSteps Forward, 

Assignments

Ed DeMeo (NREL Consultant)

3:00 p.m. Adjourn
71 

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Appendix C. Workshop Presentation Materials
Offshore Wind Electrical Safety 

Standards Harmonization Workshop

Welcome and Opening 

Walt Musial

Principal Engineer, National Renewable Energy Laboratory (NREL)

Chairman, American Wind Energy Association (AWEA) Offshore 

Wind Subcommittee

Offshore Wind Electrical Safety Standards Harmonization Workshop

Tuesday, Feb 11-12, 2020, at the Flatirons Campus,

National Renewable Energy Laboratory

National Wind Technology Center
NREL | 2

Opening Comments

• Welcome

• Introductions

• Call-in protocol

• Meals and refreshments

• Bureau of Ocean Energy Management (BOEM)/Bureau of 

Safety and Environmental Enforcement (BSEE) Opening 

Remarks

• NREL overview
NREL | 3

Electrical Standards Project Objectives

• Objective for the Overall Project:

– Develop and document published, publicly available “record of expert opinion” for application of 

relevant electrical safety standards in domestic offshore wind installations

– Inform Offshore Compliance Recommended Practices (OCRP)-1 to help deliver an American 

National Standards Institute (ANSI)-approved offshore wind electrical safety standard 

• Project Approach

– Develop a list of relevant standards

– Compare and contrast relevant standards from both Europe and the United States

– Identify significant differences, and offer recommendations on resolution or acceptance of 

differences, based on understood real-world consequences (level of risk)

– Produce a public guidance report on Workshop outcome

• Objectives for the Workshop:

– Review recent efforts to identify relevant standards from both Europe and the United States

– Identify and assess commonalities and differences; highlight differences to understand magnitude 

of material consequences

– Discuss differences and propose resolutions for most significant discrepancies

– Summarize range of views in cases not amenable to immediate resolution

– Compile information from the discussions relevant to preparation of the guidance document
Messaging + Blue 

Infographic 

Content

NREL | 4

\

Solar

Wind 

Water

Geothermal

Renewable

Power

Bioenergy

Vehicle Technologies

Hydrogen

Sustainable 

Transportation

Buildings

Advanced Manufacturing

Government Energy 

Management

Energy 

Efficiency

Grid Integration

Hybrid Systems

Energy Systems

Integration

NREL Science 

Drives Innovation
NREL | 5

NREL Quick Facts

• 2,685 Employees, Postdoctoral Researchers, 

Interns, Visiting Professionals, and 

Subcontractors

• Patents Issued for NREL Technologies to Date 571

• More than 1,700 Scientific and Technical Materials 

Published Annually

• 3 National Centers

• 16 Research Programs

• 871 Active Partnerships with Industry, 

Universities, Foundations, and Governments

• More than 70 Countries Represented by Staff

• 65 R&D 100 Awards
NREL | 6

• The National Wind Technology Center (NWTC) at the Flatirons Campus was established in 1977 and is an ideal setting 

for evaluating the reliability and performance of wind turbines. Approximately 150 staff work on-site in Wind and 

Marine Hydrokinetic technology.

• Key land-based and offshore wind research facilities:

 Structural research

 Dynamometer research

 Controllable Grid Interface (CGI)

 Energy storage

 Field validation sites

 Composites Manufacturing Education and Technology (CoMET)

 High-Performance Computing (HPC)

 Integrated energy systems at scale

NREL’s Flatirons Campus
NREL | 7

Workshop Agenda—Page 1
NREL | 8

Workshop Agenda—Page 2
Offshore Wind Electrical Safety Standards Workshop Roles 

Plenary Session

Facilitator: Ed DeMeo

Chapter Leads: Brandon Burke and Emily Chambers

Turbine Breakout

Facilitator: Ed DeMeo

Chapter Lead: Michelle Fogarty

Medium/small conference room

Substations Breakout

Facilitator: Brandon Burke

Chapter Lead: Emily Chambers

Large conference room

Submarine Cables Breakout

Facilitator: Chloe Constant

Chapter Lead: Aubryn Cooperman

East Conference Room

Logistics: Cyndi Edgley

• Food and refreshments

• Site access

• Communication

• Badges and registration

• Social event planning

• Project meetings

Report: Walt/Ed (overall)

• Outline (Walt)

• Compile/post presentations

• Key findings

• Chapters – chapter leads

• Editing and oversight

Contracting: Tiffany

• Business Network for Offshore

Wind (BNOW)

• BOEM/BSEE

• Reporting

• Ed DeMeo
NREL | 10

Workshop Organizing Team

• Walt Musial—Principal Investigator and host

• Ed DeMeo—Workshop lead moderator

• Brandon Burke—BNOW

• Emily Chambers—BNOW

• Michele Fogarty—NREL

• Chloe Constant—NREL

• Aubryn Cooperman—NREL

• Cyndi Edgley—NREL

• Rebecca Green—NREL
NREL | 11

Workshop Sponsors—BSEE and 

BOEM

• Cheri Hunter—BSEE

• David Nederostek—BSEE

• Darryl Francois—BOEM
NREL | 12

Why We Are Here

David Nedorostek, BSEE Senior Electrical Engineer 

Cheri Hunter, BSEE Renewable Energy Program Coordinator

Darryl Francois, BOEM Office of Renewable Energy Programs

Offshore Wind Electrical Safety Standards Harmonization Workshop

Tuesday, Feb 11-12, 2020 at the Flatirons Campus,

National Renewable Energy Laboratory

National Wind Technology Center
NREL | 13

Contents

Workplace Safety

OCS Renewable Energy Authorization Process

Industry Plan Review

Comparison of Electrical Safety Standards

1

2

3

4

5 Next Step: Peer Review
NREL | 14

Workplace Safety

• The Department of the Interior (DOI) is the principal federal

agency for the regulation and enforcement of safety and

health requirements for outer continental shelf (OCS)

renewable energy

– Offshore wind traditionally uses international standards

– BSEE/BOEM have due diligence requirement to ensure

the safest standards are used

– Public expectation is a robust comparison to U.S.

standards with a focus on safety
NREL | 15

OCS Renewable Energy 

Authorization Process

• Intergovernmental task

force

• Call for information &

nominations (Call)

• Area identification

• Environmental reviews

• Proposed sale notice

• Final sale notice

• Auction

• Issue leases

• Site characterization 

(i.e., geophysical and 

geological surveys,

biological surveys, and 

so on)

• Site assessment plan

• Construction &

operations plan

• Facility design report

• Fabrication and

installation report

• Decommissioning

Planning & 

Analysis Leasing Site Assessment

Construction 

& 

Operations

2 Years 1-2 Years 5 Years 2 Years (+25)
NREL | 16

Industry Plan Review

• BSEE partners with BOEM to review industry submissions

(construction and operations plans, facility design reports,

fabrication and installation reports)

• U.S. offshore electrical wind industry standards are under

development

• BSEE created a comparison of U.S. versus international

electrical safety standards to assist BSEE/BOEM engineers in

performing a comprehensive assessment of a project’s

electrical design
NREL | 17

Comparison of Electrical Safety 

Standards 

• The list of standards is a starting point for establishing U.S.-specific

expectations for offshore wind electrical safety

• The list of standards will continue to evolve as BSEE/BOEM and

industry identify best practices

• Purpose:

– Highlight available standards

• United States

• European

• Canadian

• harmonized

• (incorporating international and U.S-specific requirements)
NREL | 18

Comparison of Electrical Safety 

Standards 

• Includes a list of electrical equipment subdivided into three

categories:

– Design (lightning protection, switchgear, transformer)

– Procedures (personal protective equipment [PPE], lockout/tag-out [LO/TO], equipment guarding ) and

– Reliability design (marine cable, uninterruptable power supply

(UPS)

The list focuses on what BSEE/BOEM have initially identified to be the 

most safety-critical electrical equipment and procedures.
NREL | 19

Comparison of Electrical Safety 

Standards 

• Table review:

– Does the list of standards focus on most safety-critical

electrical equipment?

– Is critical electrical equipment categorized properly?

– Are all the applicable electrical safety standards for each

electrical component captured?

– Should certification be done by a Nationally Recognized

Testing Laboratory for functionality and performance?
NREL | 20

Comparison of Electrical Safety 

Standards 

Why We Are Here

Next step: Peer review 

• International and U.S. electrical standards experts

• Members of Offshore Wind Technical Advisory Committee

(U.S. industry consensus-based, ANSI-approved,

recommended practice document)
U.S. Offshore Wind 

Standards Initiative

Walt Musial

Principal Engineer, NREL

Chairman, AWEA Offshore Wind Subcommittee

Offshore Wind Electrical Safety Standards Harmonization Workshop

Tuesday, Feb 11-12, 2020 at the Flatirons Campus,

National Renewable Energy Laboratory

National Wind Technology Center
Organizers and Sponsors

Walt Musial

Sabrina Morelli

Michele Mihelic

Tom Vinson

Liz Burdock

Elizabeth Barminski

Mike Derby

Gary Norton

Darryl Francois

Dan O'Connell

Sid Falk

Cheri Hunter/John Cushing – BSEE
BOEM/BSEE Authority to Regulate Offshore Wind

 The Energy Policy Act of 2005 authorized BOEM to grant leases on 

the Outer Continental Shelf for offshore renewables and to 

promulgate any necessary regulations

 30 CFR 585 rule was issued in 2009, covering the offshore wind 

facility development process cradle to grave; does not specify 

standards and requires best practices to be used

 From 2009-2012, the industry developed AWEA OCRP 2012, a 

consensus-based roadmap to facilitate “best industry practices”

 U.S. consensus standards and guidelines can be: 

 Adopted by developers to guide project design and approval 

 Referenced by BOEM in 30 CFR 585

 Explicitly quoted in regulations 
Project Objective

To develop a comprehensive set of consensus-based roadmaps to navigate the 

existing standards and guidelines to: 

• Facilitate safe designs and orderly deployment of U.S. offshore wind energy 

• Account for the unique offshore conditions on the U.S. Outer Continental 

Shelf and state waterways

• Provide DOI with recommended practices of industry best practices with 

procedural protections provided by ANSI process 

Initiative on U.S. Offshore Wind Standards 
• Enable a more efficient regulatory process

• Provide more confidence in design approvals by regulators

• Increase clarity in the regulatory requirements for 

developers and certified verification agents

• Create more transparency for the public 

• Increase worker safety throughout the life of project

• Lower project cost 

Why Do We Need U.S. Standards Roadmaps?
AWEA Offshore Compliance Recommended Practice (OCRP) 2012 

Current Best Practices

 AWEA OCRP 2012 is structured to mirror BOEM 30 CFR 585 “cradle 

to grave” 

 Dozens of standards and guidelines from various industries and 

certifying bodies are cited and mapped to development process 

 50+ stakeholders/subject matter experts participated between 

2009 and 2012

 AWEA OCRP published in October 2012 as a Recommended 

Practice 

AWEA OCRP 2012 is a roadmap on how to use existing standards. 

http://awea.files.cms-plus.com/FileDownloads/pdfs/AWEA%20Offshore%20RP2012%20FINAL%202012%20October%2010.pdf

Graphic source: NREL
Working Groups and Conveners

Rain Byars – Shell Renewables

Graham Cranston—SG&H Consultants

Michael Drunsic—WSP

Lorry Wagner

Matt Palmer—WSP

Mathieu Guinard—Atkins

Georg Engelmann—Excipio Energy

Bob Hobson—NKT HV Cables AB

(WG2) AWEA U.S. Floating Offshore Wind 

Systems Working Group OCRP2

(WG3) AWEA U.S. Offshore Wind 

Metocean Conditions Characterization 

Working Group OCRP3

(WG4) AWEA U.S. Geotechnical and 

Geophysical Investigations and Design 

Working Group OCRP4

(WG5) AWEA Offshore Wind Submarine 

Cables Working Group OCRP5

Lars Samuelsson—ABS

Leif Delp—Equinor 

(WG1) AWEA Offshore Compliance 

Recommended Practices (OCRP)

Maintenance Working Group OCRP1
U.S Offshore Wind Standards Initiative Organizational Structure

Electrical 

Standards 

Electrical 

Standards 
Major Steps in Developing the Recommended Practices

Internal Working 

Group:

About 12 – 24 

months

External Working Group: 

About 12 months

• Develop outline for recommended practice document

• Write first draft of recommended practice document

• Internal review of first draft (90 days)

• Internal working group draft

• Final draft submitted for OWTAP and working groups 

• OWTAP review comment period (60 days)

• Resolve OWTAP comments

• Final committee draft

• Final draft submitted for approval by WTSC

• 30-day ballot period

• Working Group resolves comments

• AWEA staff submit BSR-8 to ANSI

• Public comment is open for 45 days

• Review and resolve public comments

• (Optional appeal process)

• AWEA staff submit BSR-9 to ANSI

• ANSI approval process and publication

Process to finalize guidelines under AWEA/ANSI process may take too long. 
Electrical Content in Draft Offshore Compliance 

Recommended Practices (OCRP) 2nd Edition

Albert Fisas, GE Renewable Energy

Member OWTAP & 

OCRP Working Group

February 10, 2020

Boulder, CO

Photo Credit : Dennis Schroeder-NREL
Overview of OCRP WG1 Effort

The Working Group

● Offshore Wind Technical Standards Committee formed in Oct 2017 under 

AWEA Wind Standards Committee, Chaired by Walt Musial

● Working Groups kicked off April 2018

● All volunteer, wide industry representation

● Working Group 1 – OCRP second edition

The OCRP

● Serves as a Roadmap for application of international and US requirements 

to Offshore Wind in U.S. waters

● Addresses gaps, overlaps, and conflicts

● Does not intend to create new requirements

● Committee Draft on track for mid-2020

● Will be published as an American National Standard through AWEA/ ANSI
Electrical Author Team

● Electrical standards identified as one of the gaps in 2012 OCRP

● Electrical sections in 2nd edition draft are written by a 28 member 

author team made up of volunteers from across the industry

● Author team has conducted monthly or bi-weekly web-meetings and 

bi-annual face to face meeting throughout 2018 and 2019 to reach 

consensus on structure, topics, content, and reference standards. 

• Regulators 

• Developers

• OEMs

• CVAs

• Consultants

• Contractors

• Supply Chain

• Academics
Electrical Content in Draft OCRP ed. 2

● General Sections 

(introductory content, design basis, standards hierarchy, terms and 

definitions, references)

● Chapter 5 – Design

• 5.6 Design of Offshore Wind Turbine

• 5.6.4 Electrical Design 

• 5.6.5 Design for Occupational Health and Safety

• 5.7 Design of Offshore Substation

• 5.7.4 Electrical Design 

• 5.7.5 Design for Occupational Health and Safety

Note: Sub-sea cables are addressed in RP being developed by WG5 
Standards referenced

See Chapter 11 of Draft OCRP

Electrical Standards Include

● US Electrical Standards (NFPA, ANSI, IEEE, 

NEMA, UL, others)

● International Standards (IEC, ISO, CIGRE )

● US Offshore O&G Electrical Standards (API)
Mapping – Workshop Topics/ Draft OCRP

Workshop Topic OCRP Chapter

A. Safety Design

A-1 Arc Flash 5.6.4.7 and 5.7.4.7

A-2 Emergency Stop 5.6.4.9

A-3 Spaces Around Cabinets 5.6.4.6 and 5.7.4.6

A-6, A-7 Switchgear 5.7.9.4

A-9 Transformers 5.6.4.8 and 5.7.4.8

A-11 Lightning Protection 5.6.4.10 and 5.7.4.10

A-13 WTG Electrical Systems 5.6.4.1
Mapping – Workshop Topics/ Draft OCRP

Workshop Topic OCRP Chapter

B. Safety Procedures

B-3 Lock-Out Tag-Out 5.6.5.6 and 5.7.5.5

B-4 Equipment Guarding 5.6.4.5 and 5.7.4.5

C. Reliability Design

C-1 Safety Acceptance Testing 5.6.4.3 and 5.7.4.3

C-17 Wind Turbine Elevators 5.6.5.4

C-18 Hoist/ Winch/ Cranes 5.6.5.5 and 5.7.5.4

C-21 Emergency Power 5.6.4.13 and 5.7.4.13

C-22 Sockets and Plugs 5.6.4.11 and 5.7.4.11

C-25 Cathodic Protection 5.6.3.4.2 and 5.6.3.4.3

C-26 Grounding and Bonding 5.6.4.10 and 5.7.4.10
Recommendations

• Use recommended practices and reference 

standards from draft OCRP Ed 2

• Understand context of electrical sections within larger recommended 

practice (introductory sections, design basis approach, interfaces, 

different types of design oversight, acceptance testing, etc.)
109 

This report is available at no cost from the National Renewable Energy Laboratory at www.nrel.gov/publications.

Appendix D. Standards Comparison Table

Over the past several years, the Bureau of Safety and Environmental Enforcement (BSEE) has 

been actively preparing for growth in applications for offshore wind power plants planned for the 

U.S. Outer Continental Shelf. To this end, BSEE technical staff have been compiling electrical 

safety standards to apply to domestic offshore installations. Recognizing that most existing 

offshore wind power plants have been built in Europe and certified to European standards, BSEE 

is examining similarities and differences among corresponding U.S. and European standards. 

A key step in that process was BSEE’s assembly of a table listing relevant standards applicable 

to major components, processes, and procedures associated with offshore wind construction and 

operation. Table items were organized into three categories: safety design, safety procedures, and 

reliability design. For each item, European and U.S. standards were listed side by side.3 In early 

2019, with the aim of improving the accuracy of the table contents, BSEE sought and received 

feedback from several wind turbine original equipment manufacturers. That process elicited a 

number of suggestions and proposed changes. 

In late 2019, BSEE engaged NREL’s organizing team for the workshop covered in this report to 

shape the draft table and its contents into a form likely to engender discussion and feedback from 

a larger group of offshore wind industry participants. For each item in the table, the team posed a 

number of questions, based on comments from BSEE and the previous original equipment 

manufacturer reviewers. The revised table was sent to all participants prior to the workshop to 

prompt relevant discussion during the event. Subsequent to the workshop, the table was revised 

to reflect input from the meeting’s discussions. In addition, many of the questions were restored 

to their original format as comments.

The revised postworkshop table was then sent to the members of the turbine breakout group for 

additional feedback. The table was subsequently refined, based on additional input received. 

Finally, the table was reviewed by all participants as part of their review of the entire workshop 

report and revised once again to reflect additional input. For many of the table’s entries, there is 

broad agreement. For others, there are differing views. In those cases, the organizers have 

attempted to include the range of views expressed. 

Through the iterative process described earlier, the organizing team believes that this table 

provides relevant and accurate guidance to offshore wind power plant regulators as they consider 

applications for offshore wind projects in the interim period before definitive regulatory 

guidelines become available. It should be viewed as a work in progress that will evolve as the 

offshore wind industry and BSEE engage over the coming months. Although the way forward is 

clear in many cases, significant questions remain. For those cases open questions, the organizing 

team’s hope is that this table provides information helpful to regulators as they apply their best 

judgment to resolve any open issues. 

The standards table in its current form follows.

3 In some cases, particular standards are listed in the table with double or even triple designations (e.g., International 

Electrotechnical Commission (IEC) 61400-25-2 and DS/EN 61400-25-2 or IEC 60204-1, EN/IEC 60204-1, and BS EN 

60204-1). Users of this table should be aware that there may or may not be material differences between versions of 

standards with the same numbers. In most cases, the IEC version would be most applicable for U.S. installations.
110 

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Table D-1. U.S. and International Offshore Wind Electrical Safety Standards Comparison Table

A. Safety Design

Ref Category Relevance International 

Electrotechnical 

Commission (IEC)

IEC and European Union (EU) 

Directives

United States Certification

A-1 Arc Flash/Arc 

Blast Analysis

Arc Flash Labelingi

Turbines 

and 

Substations

IEC 61482-2

IEC TR 61641

IEC 62271-200

IEC 60909-0 

Occupational Safety and Health (OSH)

Framework Directive 89/391/EEC

European Norm (EN) 50110-1 

Institute of Electrical and 

Electronics Engineers 

(IEEE) 1584

National Fire Protection 

Association (NFPA) 70E

Canadian Standards 

Association (CSA) Z462

A-1 Comments

• All listed standards have similar requirements, but IEC and IEC and EU do not include arc flash labeling requirements.i 

• The labeling requirement is standard for U.S. land-based wind, but perhaps new to offshore vendors in other markets. For other markets, hazards 

are addressed in design and lockout/tagout (LO/TO) instructions, but application of an arc flash sticker is not standard. A suggested approach for 

resolving this difference follows: IEC standards will yield a level of safety similar to that with the U.S. standards. Hence, use of IEC standards should 

be acceptable to justify compliance, and then the arc flash sticker can be applied per IEEE 1584/NFPA 70E. However, if a sticker is used on IECtested and -rated equipment, the boundary statement and other critical details should correlate to the IEC-defined levels. Although either system 

could be acceptable for safety, the boundary or class definitions should not be mixed. 

• The Bureau of Safety and Environmental Enforcement (BSEE) recommends that developers utilize NFPA 70E or IEEE approaches on arc flash labeling 

requirements.

• Industry views IEEE 1584 and NFPA 70E as the most appropriate standards for the U.S. market.

• Arc flash labeling requirements can be aligned through BSEE’s Safety Management System. 

• The above IEC standards could be followed for wind applications, with proper justification.

• CSA Z462 is essentially the same as, and harmonized with, NFPA 70E.

• On labeling, but not for arc flash, IEEE and NFPA require breaker panels to include panel schedule labeling. The corresponding IEC standards do not.
111 

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Ref Category Relevance IEC IEC and EU Directives United States Certification

A-2 Emergency Stop –

Design

Turbines 

and 

Substations

IEC 60204-1 DS/EN Independent System Operator

(ISO) 13850

DS/EN 61400-25-2 

ISO 13850; ISO 13849-1 

DNVGL-ST-0438

EN/IEC 60204-1 

British Standard (BS) EN 60204-1 

NFPA 79

CSA C22.2 No. 301

Certification 

should be carried 

out in accordance 

with the design 

standards used 

and employ 

nationally 

recognized 

testing laboratory 

(NRTL) approval if 

called for in those 

standards.

A-2 Comments

• The following standards are acceptable: ISO 13850, IEC 60204-1 (aka EN 60204-1), NFPA 79, and CSA C22.2 No.301.

• Addition of ISO 13849-1 is recommended because it is also heavily used for the design of the overall emergency stop systems.

• A new Canadian standard was published in 2016: CSA C22.2 No. 301. This standard draws heavily on several standards for core material, including 

IEC 60204-1 and NFPA 79. CSA C22.2 No. 301 uses identical definitions for stop-function categories.
112 

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Ref Category Relevance IEC IEC and EU Directives United States Certification

A-3 Spaces Around 

Cabinets and 

Compartments 

and Equipment

- Low Voltage

- High Voltage

(Adequate 

Workspace)

Turbines 

and 

Substations

Low Voltage

IEC 60364-7-729

IEC 61439

High Voltage

IEC 61482

IEC 60298

IEC 62271-200

Low Voltage

EN 50110-1 

EU Directive

2014/35/EU

High Voltage

EN 50110-1 

Low Voltage

NEC (NFPA 70)

Article 110.26 

Article 110.34

NFPA 70B; NFPA 70E

OSHA 29 CFR 1910.269

OSHA 29 CFR 1910.305 

OSHA 29 CFR 1926.403

High Voltage

IEEE C2 (National 

Electrical Safety Code 

[NESC]) 

Certification 

should be carried 

out in accordance 

with the design 

standards used 

and employ NRTL 

approval if called 

for in those 

standards.

A-3 Comments

• The terms “high voltage” and “low voltage” are subjective. Actual voltage ranges should be used instead.

• EU directive (low voltage) and EN 50110-1 (high voltage) are acceptable because of their close alignment with OSHA 29 CFR 1910.269.

• Initially, BSEE recommended that the listed IEC standards not be used, because they are less stringent than the EU directives and EN standards. 

However, the following comments offer an alternative view.

• For cabinets with exposed live voltages, the EU/EN standards will usually require space around electrical cabinets to be increased to comply with 

OSHA and IEEE-NESC.

• Going forward, it should be recognized that the NFPA, OSHA, and IEEE guidance primarily refers to work on or near exposed live parts. Exposed live 

parts are generally prohibited in much of the IEC guidance. 

• Requirements from IEC 60364, IEC 60204-1, IEC 60204-11, and IEC 61936-1 include measures to protect from electric shock, such as isolation of 

hazardous energy and the use of protective barriers.

• Because the distances around electrical cabinets from IEC standards take shock hazard into consideration, BSEE should consider accepting these 

distances if exposed live parts are not present when the cabinets are opened.
113 

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Ref Category Relevance IEC IEC and EU Directives United States Certification

A-4 Electrical Safety 

Equipment 

(Ground Fault 

Circuit 

Interrupter [GFCI]

– Residual 

Current Device 

[RCD]) 

Turbines 

and 

Substations

IEC 60364

IEC 61439

IEC 60204-1 

NFPA 70E

Underwriters 

Laboratories (UL) 943; 

UL 1053

OSHA: 29 CFR 

1926.404(b)(1)(ii)

A-4 Comments

• OSHA regulations and NFPA 70E are acceptable because of corrosive environments.

• IEC-60204-1, which refers to IEC-60364-4-41, has been added per industry recommendation for protection against electrical shock.

• UL 943 has been added per industry recommendation. 

• Europe focuses on RCDs. European RCD breakers are not equivalent to the U.S. GFCI breakers. The trip level of an RCD is significantly higher than 

the 4-6 mA point of a GFCI, so they are not interchangeable. This distinction is addressed in the following comment.

• BSEE could consider allowing RCDs and residual current circuit breakers with overcurrent protection [RCBO] devices designed to IEC standards (e.g., 

IEC 60364-6), as long as trip time vs. fault current as defined in UL 943 is fulfilled. Note that, while RCDs and RCBOs may have higher fault current 

ratings, they often have faster trip times than GFCIs.

• Based on the NFPA 70/UL 943 selector guide, Class C protection is sufficient when all relevant tools are double isolated and/or grounded. 

Commonly used 30 mA RCBOs designed toward IEC standards can fulfill the trip time vs. fault current requirements as defined for Class C.
114 

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Ref Category Relevance IEC IEC and EU Directives United States Certification

A-5 Adjustable Speed 

Drives

Turbines IEC 61800-1 (DC)

IEC 61800-2 (AC)

IEC 61800-4 

IEC 61800-5-1 

IEC 62477-1

BS EN 61800-1 (DC)

BS EN 61800-2 (AC)

BS EN 61800-3 (test methods)

BS EN 61800-4 

BS EN 61800-5-1 

BS EN 61800-5-2 

BS EN 61800-9-1 

Danish Standard (DS)/Cenelec 

Technical Report (CLC/TR) 61800-6 

UL 1741; UL 61800

UL 61800-5-1 

UL 61800-5-2 

UL 62109

National Electrical 

Manufacturers 

Association (NEMA)

Industrial Control and 

Systems (ICS) 61800-1 

(DC)

NEMA ICS 61800-2 (AC)

NEMA ICS 61800-4 (AC)

CSA-C22.2 No. 274

IEEE 1566

Certification 

should be carried 

out in accordance 

with the design 

standards used 

and employ NRTL 

approval if called 

for in those 

standards.

A-5 Comments

• Acceptable standards include UL 61800-5 series, NEMA ICS 61800 series, and BS EN 61800 series.

• IEC 61800-5-1 and IEC 62477-1 could also be considered as acceptable standards, with suitable justification, even though BS standards may be 

more stringent in some areas.

• Regarding certification, frequency drives used for motors, and so on, are provided by the suppliers with certificates of compliance with relevant 

standards, which often includes IEC standards. This is also the case for the wind turbine main converters.

• UL 508C has been withdrawn and replaced by UL 61800-5-1.
115 

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Ref Category Relevance IEC IEC and EU Directives United States Certification

A-6 Switchgear (High 

Voltage)

Turbines 

and 

Substations

IEC 62271 Series

IEC 62271-1 

IEC 62271-100

IEC 62271-102

IEC 62271-103

IEC 62271-106

IEC 62271-200

IEC 62271-203

IEC 62271-205

IEC TR 62271-307

IEC TS 62271-210

BS 6867; BS EN 62271-104

BS PD IEC/TR 62271-307

German Institute for Standardization 

(DIN) IEC/TR 62271-307

DIN EN 62271-200

DS/EN 62271-1; DS/EN 62271-100

DS/EN 62271-106; DS/EN 62271-202

DS/EN 62271-205 

DS/EN IEC 62271-102

DS/IEC/IEEE 62271-37-013

EN IEC 62271-205

AS 62271.1; AS 62271.200

IEEE 1547

IEEE C37 series

IEEE C37.100.1

IEEE C37.20.2

IEEE C37.301

IEEE/IEC C37.60

IEEE/IEC 62271-37-013

IEEE/IEC 62271-37-082

Certification 

should be carried 

out in accordance 

with the design 

standards used 

and employ NRTL 

approval if called 

for in those 

standards.

A-6 Comments

• Acceptable standards are IEC/IEEE and/or DS/IEC/IEEE. These are harmonized standards.

• IEC 62271-203, applicable for voltages above 52 kilovolts (kV), has been added per industry recommendation.

• For < 52-kV products, the switchgear is designed and tested according to IEC 62271-200.

• For > 52 (72.5-kV) products, the switchgear is designed and tested according to IEC 62271-203, with the internal arc classification according to IEC 

62271-200 and/or IEC 62271-203.

• Regarding certification, switchgear items receive numerous type tests during their development. Switchgear are type tested toward IEC and IEEE 

standards by accredited laboratories. For example, PEHLA provides type-testing services toward both IEC and IEEE standards. Some participants 

recommend against a requirement for repeated testing by an NRTL. However, others recommend the following approach: if using U.S. codes and 

regulations that require NRTL certification, then an NRTL should be used to certify. If using IEC standards, then tests with alternative accredited labs 

for those standards may be acceptable.

• Applicable standards may change for switchgear with a circuit breaker design (European) and not interrupter design (mainly used in the United 

States). For example, the following standards are applicable having a circuit breaker design: IEEE Std C37.100 (Common), 37.04/06/09/10 (CB), 

37.122 (gas-insulated switchgear [GIS]).
116 

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Ref Category Relevance IEC IEC and EU Directives United States Certification

A-7 Switchgear 

(Medium 

Voltage) 

Substations IEEE C37.010 

IEEE C37.04

IEEE C37.06 

IEEE C37.09

IEEE C37.13 

IEEE C37.20.2

IEEE C37.20.6

IEEE C37.24

American National 

Standards Institute 

(ANSI)/NEMA C37.54

ANSI/NEMA C37.55

NEMA SG 10

National Electrical 

Contractors Association 

(NECA) National 

Electrical Installation 

Standards (NEIS) 430

CSA-C22.2 No. 31

Certification 

should be carried 

out in accordance 

with the design 

standards used 

and employ NRTL 

approval if called 

for in those 

standards.

A-7 Comments

• IEEE harmonized standards are acceptable for addressing both medium- and high-voltage switchgear.

• Industry recommends that BSEE includes IEC standards for switchgear among acceptable standards.

• Regarding certification, switchgear items receive numerous type tests during their development. Switchgear are type tested toward IEC and IEEE 

standards by accredited laboratories. For example, PEHLA provides type-testing services toward both IEC and IEEE standards. Some participants 

recommend against a requirement for repeated testing by an NRTL. However, others recommend the following approach: if using U.S. codes and 

regulations that require NRTL certification, then an NRTL should be used to certify. If using IEC standards, then tests with alternative accredited labs 

for those standards may be acceptable.
117 

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Ref Category Relevance IEC IEC and EU Directives United States Certification

A-8 Switchgear 

(Low Voltage)

Substations IEC 60947-1&2&3

IEC 60947-4-1 

IEC 60947-4-2 

IEC 60947-5-1 

IEC 60947-5-2 

IEC 60947-7-1 

IEC 60947-7-2 

IEC 60947-7-3 

IEC 60947-7-4 

IEC 61439-1 

IEC 61439-2 

IEC 61439-3 

IEC 61439-4 

IEC 60204-1 

IEC 60364-5-53

IEC TR 61912-1 

BS

BS 6423

BS EN 60947-4-1 

DS

DS/EN 61439-1 

DS/EN 61439-2 

UL 60947-1

UL 60947-4-1 

UL 60947-4-2 

UL 60947-5-1 

UL 60947-5-2 

UL 60947-7-1 

UL 60947-7-2 

UL 60947-7-3 

UL 60947-7-4 

(above items 

harmonized with IEC 

60947 series)

IEEE C37 series

IEEE C37.20.1

CSA-C22.2No.60947-4-1 

Low-Voltage 

Switchboards

IEEE C37 series

NECA NEIS 400 

UL 891

Certification 

should be carried 

out in accordance 

with the design 

standards used 

and employ NRTL 

approval if called 

for in those 

standards.

A-8 Comments

• Acceptable standards include UL 60947 series, CSA-C22.2 No. 60947 series, and BS EN 60947 series. 

• Note that CSA and BS EN are harmonized with UL 60947 series. 

• IEC-60204-1 has been added per industry recommendation.

• IEC-60439 has been replaced by IEC-61439 series.

• For grounding protection, IEC-60204-1 and IEC-60364-5-54 can be used for calculating the grounding electrode.

• IEC 60364-5-53 has been added per industry recommendation.

• Regarding certification, components normally come with type-testing documentation from the supplier. Some participants recommend against a 

requirement for repeated testing by an NRTL. However, others recommend the following approach: if using U.S. codes and regulations that require 

NRTL certification, then an NRTL should be used to certify. If using IEC standards, then tests with alternative accredited labs for those standards 

may be acceptable.
118 

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Ref Category Relevance IEC IEC and EU Directives United States Certification

A-9 Transformers Turbines 

and 

Substations

IEC 60076 series

IEC 60076-1 

IEC 60076-11

IEC 60076-13

IEC 60076-3 

IEC 60076-5 

IEC 60076-8 

IEC 60076-16

IEC 61936-1 

EN 60076-16

EN 61558-1 

EN 61558-2-16

EN 61558-2-4 

EN 61558-2-6 

BS EN 60076-11

BS EN 60076-16

BS PD IEC TS 60076-20

DS/EN 60076-16

Austrian Standard (OVE/ONORM) 

EN 60076-16

29 CFR part 1910 subpart S 

Electrical section 305 (j) (5);

National Electric Code (NEC)

sections 450.21 through 

450.27 and 450 Part III;

NESC Rule 152 Location and 

arrangement of power 

transformers and regulators,

and Rule 124 Guarding live 

parts

UL 1561 UL 1562

IEEE/ANSI C57 Series

IEEE/IEC 60076-16

IEEE 4 IEEE 259

IEEE 1276 IEEE 1538

IEEE C2 (NESC)

Low Voltage

UL 5085-1 UL 5085-2 

UL 5085-3 

CAN/CSA-C802.1

CSA-C22.2 No. 66.1 & .2 &.3

Certification 

should be 

carried out in 

accordance with 

the design 

standards used 

and employ 

NRTL approval if 

called for in 

those standards.

A-9 Comments

• Acceptable standards include IEEE/IEC 60076 and/or BS EN 60076 harmonized standard. 

• Note that when installed inside the tower or nacelle, a dry transformer or a transformer with nonflammable liquid should be used. There is also 

industry support for a “less-flammable” liquid rather than a “non-flammable” liquid. Liquids having a fire point higher than 300 C meet the 

requirements for “less-flammable” liquid, as defined in NEC 450.23. This is equivalent to Class K liquid according to IEC 61039. Adequate 

justification would also be needed.

• IEC 61936-1, applicable for overall installation of transformers, has been added per industry recommendation.

• IEC 60076-16, because it is specific to wind turbines, has been added per industry recommendation. 

• Regarding certification, type testing is often carried out on the transformer by IEC-accredited laboratories. Some participants recommend against a 

requirement for repeated evaluation and testing by an NRTL. However, others recommend the following approach: if using U.S. codes and 

regulations that require NRTL certification, then an NRTL should be used to certify. If using IEC standards, then tests with alternative accredited labs 

for those standards may be acceptable.

• Additional U.S. codes and regulations for transformer installation and protection have been added to the table.
119 

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Ref Category Relevance IEC IEC and EU Directives United States Certification

A-10 Safety of 

Machinery

Turbines 

and 

Substations

IEC 60204-1

IEC 60204-11

IEC 62061

IEC 62745

Note that voltage levels 

above 36 kV are not 

covered by the above 

standards.

EN/IEC 60204-1, -11

EN/IEC ISO 12100

ISO 12100 ISO 13849-1 

ISO 13849-2 ISO 14119

ISO 14120 ISO 14122-1 

ISO 14122-2 ISO 14122-3 

ISO 14122-4 

BS EN ISO 13849-1 

BS EN ISO 13849-2 

BS EN ISO 14122-1 

BS EN ISO 14122-2 

BS EN ISO 14122-3 

BS EN ISO 14122-4 

BS EN IEC 60204-11

DS/EN ISO 13850

EU Directive: 2006/42/EC

DNVGL-ST-0361

BS EN 50308

NFPA 79

NFPA 70

CSA-C22.2 No. 301

Certification 

should be 

carried out in 

accordance with 

the design 

standards used 

and employ 

NRTL approval if 

called for in 

those standards.

A-10 Comments

• Standard CSA-C22.2 No. 301 is acceptable, as it is reasonably well-aligned with NFPA 79.

• BSEE will also accept EN/IEC 60204-1, -11 and EN/IEC ISO 12100, which are harmonized to the IEC and EN standards. Intertek uses both standards 

as part of their certification process.

• This is a very broad topic. Overall design for machine safety for wind turbines involves the overall control and operation strategy, as well as specific 

measures to protect from rotating equipment, electrical shock, fluids under pressure, and many other hazards.

• Regarding certification, design for machine safety is evaluated and certified as part of the overall turbine type certification process. Some, but not 

all, participants believe there should be no requirement for repeated testing by an NRTL.

• NFPA is also relevant and has been added to the table.
120 

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Ref Category Relevance IEC IEC and EU Directives United States Certification

A-11 Lightning 

Protection

Turbines 

and 

Substations

IEC 61400-24

IEC 62305-3 

IEC 62305-4 

BS EN/IEC 62305

BS EN 61400-24

EN 61400-24

DIN EN 61400-24

NFPA 780

CSA IEC 61400-24

ANSI/CAN/UL 96

A-11 Comments

• An acceptable standard is the CSA IEC 61400-24 harmonized standard.

• However, industry recommends using IEC 61400-24 rather than the CSA-harmonized version to avoid any potential deviations.

Ref Category Relevance IEC IEC and EU Directives United States Certification

A-12 Electrical 

Enclosures/ 

Control Panel 

(Degrees of 

Protection)

Turbines 

and 

Substations

IEC 60529

IEC 61936-1 

BS EN 60529

AS 60529

NEMA ANSI/IEC 60529

NEMA 250

UL 50

UL 508A

UL 50E

Certification 

should be 

carried out in 

accordance with 

the design 

standards used 

and employ 

NRTL approval if 

called for in 

those standards.

A-12 Comments

• An acceptable standard is the NEMA ANSI/IEC 60529 harmonized standard.

• Note that UL 50E “Type” ratings and IEC 60529 “Ingress Protection (IP)” ratings are acceptable, but there are some incompatibilities with the ratings 

systems, especially with respect to protection from oil or hydraulic fluid.

• There should be a focus on IP terminology.
121 

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Ref Category Relevance IEC IEC and EU Directives United States Certification

A-13 Wind Turbine 

Electrical Systems

Turbines IEC 61400-1

IEC 61400-3-1 (fixed)

IEC 61400-3-2 (floating)

IEC System for 

Certification to 

Standards Relating to 

Equipment for Use in 

Renewable Energy 

Applications (IECRE) 

Operational Document 

(OD)-502

IEC 61936-1

DNVGL-ST-0076

EU Directive 2006/42/EC

BS EN 50308 

DIN EN 61400-3 (superfluous)

EN IEC 61400-3 (superfluous)

CAN/CSA-C22.2 No. 272

CAN/CSA-C61400-1 

CAN/CSA-C61400-3 

NFPA 70 (NEC)

NFPA 70B

NFPA 70E

OSHA 29 CFR 1910.269

UL 6141

Certification 

should be 

carried out in 

accordance with 

the design 

standards used 

and employ 

NRTL approval if 

called for in 

those standards.

A-13 Comments

• Acceptable standards include UL 6141 and CAN/CSA-C22.2 No. 272 (which is similar to UL 6141).

• Canadian (CAN)/CSA C61400-3 is redundant relative to the outdated version of IEC 61400-3.

• Note that the above standards are harmonized and reference IEC 61400-3. Intertek uses these standards as part of their certification process.

• Some industry representatives recommend focusing on IEC 61400-3-1 and IEC 61400-3-2, and adding IEC 61400-1 as an acceptable standard. 

Significant revision and expansion of the Electrical Systems section is included in the 2019 revision of the IEC 61400-1 wind turbine design standard.

• Others recommend following U.S. codes and regulations stated in this table as primary references for the design basis of offshore wind turbines in 

the United States.

• In general, industry recommends against using an EN version when a corresponding IEC version exists.

• For example, DIN EN 61400-3 and EN IEC 61400-3 seem superfluous.

• BS EN 50308 applies more to A-10 than A-13. It has been added there. Also, EU Directive 2006/42/EC applies here as well as in A-10. It has been 

added here.

• If using U.S. codes and regulations for the wind turbine electrical system, then an NRTL should be used to certify the electrical components of the 

system. If something has already been certified, then no reevaluation is needed unless it has been changed or there are details beyond what has 

been certified.

• Regarding certification, the wind turbine electrical system is type tested and certified as part of the type certification process (IECRE OD-501). Some 

industry representatives recommend against a requirement for repeated evaluation and testing by an NRTL. However, others recommend the 

following approach: if using U.S. codes and regulations for the wind turbine electrical system, then an NRTL should be used to certify the electrical 

components of the system. If something has already been certified, then no reevaluation is needed unless it has been changed or there are details 

beyond what has been certified.
122 

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Ref Category Relevance IEC IEC and EU Directives United States Certification

A-14 Fire Prevention 

and Fire 

Protection

Turbines 

and 

Substations

ISO 19353 ISO 7240-8

ISO/TS 7240-9 

DNVGL-SE-0077 

DNVGL-ST-0438

BS 5839-1 BS EN 12094-9 

BS ISO 7240-8 

EN 54

EU Directive: 2006/42/EC 

(section 1.5.6)

DIN EN 12094-9 

DS/EN 12094-9 DS/EN 54-29

ONORM EN 12094-9

OSHA 29 CFR 1926.24

OSHA 29 CFR 1926.150 

OSHA 29 CFR 1926.151

NFPA 72

NFPA 850

NEMA SB 11

NEMA SB 23

UL 864

Certification 

should be 

carried out in 

accordance with 

the design 

standards used 

and employ 

NRTL approval if 

called for in 

those standards.

A-14 Comments

• Further assessment is needed to determine which IEC standards are compatible with U.S. regulations and standards.

• On an interim basis, the following standards are acceptable: OSHA regulations, NFPA 72, and NEMA standards.

• Industry recommends including ISO 19353 as an acceptable standard.

• A fire risk assessment of the wind turbine is often performed in cooperation with third-party fire risk assessment experts. This assessment can be 

reviewed during the certified verification agent process.

• Regarding certification, this topic is also covered in the wind turbine type certificate. Some industry representatives recommend against a 

requirement for repeated certification by an NRTL. Others recommend the following approach: if using U.S. codes and regulations that require 

NRTL certification, then an NRTL should be used to certify.

• Evaluation of fire resistance and fire prevention are included in the IECRE-OD501 type certification process.

• See also comments on fire and smoke behavior under C-6.
123 

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Ref Category Relevance IEC IEC and EU Directives United States Certification

A-15 Converter/ 

Inverter

Turbines 

and 

Substations

IEC 62477-1&2 

IEC 62909-1 

IEC 61800 series

BS PD IEC/TR 60146-1-2

BS EN 61400-7 

DIN EN 62477-1 

UL 347A 

UL 508C

UL 1741

UL 61800-5-1

UL 61800-5-2

UL 62109-1 

CAN/CSA-C22.2 No. 14

CAN/CSA-C22.2 No 107.1

Certification 

should be 

carried out in 

accordance with 

the design 

standards used 

and employ 

NRTL approval if 

called for in 

those standards.

A-15 Comments

• The following standards are acceptable: UL 508C, CAN/CSA C22.2 No 107.1, UL 1741, UL 61800-5-1, UL 61800-5-2, UL 62109-1, and CAN/CSA-C22.2 No. 14.

• Industry recommends that converters comply to IEC 62477-1 and IEC 62477-2, respectively.

• Industry recommends including the IEC 61800 (series) of standards as acceptable. These are the leading standards for converter/inverter design 

and testing and have been included in the above list.

• For medium-voltage converters, UL 347A has been added to the table.

Ref Category Relevance IEC IEC and EU Directives United States Certification

A-16 Fixed Ladder 

Inside Wind 

Turbine

Turbines ISO 14122-1

ISO 14122-4 

BS EN ISO 14122-4 

EN50308

OSHA 29 CFR 1910.23

OSHA 29 CFR 1910.269(h)

ANSI/American Society of 

Safety Professionals (ASSP)

A1264.1

American Ladder Institute 

(ALI) ANSI Accredited 

Standards Committee (ASC) 

A14.3

A-16 Comments

• Any of the listed standards are acceptable.

• Some industry representatives recommend compliance with the European standards, which they view as more practicable (EN50308). Others disagree.

• Note that work on wind turbines generally requires use of a hard hat as PPE. This provides risk reduction when climbing ladders in areas with 

restricted clearance.

• An industry safety manager recommends that fixed ladders should comply with OSHA standards inside the United States and its waters. European 

standards have not provided enough clearances for personnel and in the onshore industry OSHA will not give a variance for non-compliant ladders 

from Europe. The fixed ladder standard in OSHA is well established and should be utilized in the United States. 
124 

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B. Safety Procedures

Ref Category Relevance IEC IEC and EU 

Directives

United States Certification

B-1 Working On 

or Near Live 

Equipment

Turbines and 

Substations

IEC 60364-

5-52

BS 6626 BS 7671

EU Directive

2009/104/EC

OSHA 29 CFR 1926.960

OSHA 29 CFR 1910 Subparts R, S

NFPA 70E Ch.1 Art.100-130

B-1 Comments

• In BSEE’s preliminary assessment, the following standards are acceptable: EU directive (2009/104/EC), BS standards, and IEC 60364-5-52.

• However, one industry original equipment manufacturer (OEM) believes that further assessment is needed to determine which IEC standards and 

EU directives are compatible with U.S. regulations and standards.

• A-3 comments also apply here.

• An industry safety manager recommends that OSHA and NFPA 70E should be the only allowable standards for the United States. These are 

regulations that technicians and personnel are already trained in across all U.S. industries. These are well-established in the United States, and 

manufacturers should not be allowed to dictate safety procedures. 

Ref Category Relevance IEC IEC and EU

Directives

United States Certification

B-2 Personnel 

Protective 

Equipment 

(PPE)

Turbines and 

substations

IEC 61482-

2 

(European 

Equivalent 

to 

American 

Society of 

Testing 

Materials 

[ASTM]

F1506)

OSH Framework 

Directive 

89/391/EEC

ASTM F1506 NEMA ABP 10

NFPA 2112

NFPA 70 NEC – Art. 110.16

NFPA 70B NFPA 70E

OSHA 29 CFR 1910.137

- OSHA refers to Subpart I requirements, 

which refer to ANSI and ASTM standards

- NFPA also refers to applicable ANSI and

ASTM standards

B-2 Comments

• In BSEE’s preliminary assessment, the following standards are acceptable: OSH Framework Directive (89/391/EEC) and/or IEC 61482-2.

• However, one industry OEM believes that further assessment is needed to determine which IEC standards and EU directives are compatible with 

U.S. regulations and standards.

• Industry recommends enforcing NFPA 70E to address arc flash risk.

• Note that, relative to electrification risk, the European standards are more restrictive than the U.S. standards.
125 

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Ref Category Relevance IEC IEC and EU

Directives

United States Certification

B-3 LockoutTagout 

(LO/TO)

Turbines and 

Substations

IEC 60204-

1 

EU Dir. 2009/104/EC

EU Dir. 2006/42/EC

EN ISO 14118 

AS 4024.1603

ISO 12100 (6.2.11.1)

ISO 4413 (5.4.7.2.1)

NFPA 70E NFPA 70B NFPA 70

OSHA 29 CFR 1910

ANSI/ASSP Z224.1

B-3 Comments

• NFPA 70E is an acceptable standard. 

• Industry recommends that IEC 60204-1 (e.g. §5.4) be included in the list of acceptable standards, because it addresses design of equipment for 

LO/TO.

• Industry recommends including IS0 12100 (see §6.2.11.1) and ISO 4413 (see 5.4.7.2.1) as additional standards applicable for LO/TO (often referred 

to as “isolation of hazardous energy” internationally). The industry recommendations have been added to the above list.

• An industry safety manager recommends that only U.S. LO/TO standards and practices should be followed. As project owners, they will not allow 

anyone to work on their project site who does not follow NFPA 70 E and OSHA standards for control of hazardous energies and LO/TO.

Ref Category Relevance IEC IEC and EU

Directives

United States Certification

B-4 Equipment 

Guarding 

(Energized 

Component) 

Turbines and 

Substations

IEC 60204 EN ISO 12100

ISO 14120 ISO 

13857 

AS 4024.1601

BS EN ISO 14120

EN 50308

ISO 14119

ISO 14122-3

OSHA 29 CFR 1910.212 (Sub.O)

NFPA 70 NFPA 70E NFPA 79 NFPA 70B 

AMT ANSI B11.19

B-4 Comments

• An acceptable standard is EN ISO 12100 harmonized for equipment guarding (energized component).

• EN 50308, ISO 14119, and ISO 14122-3 (guard rails) have been added per industry recommendation.
126 

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C. Reliability Design

Ref Category Relevance IEC IEC and EU Directives United States Certification

C-1 Safety 

(Testing/Fit 

for Purpose) 

–Acceptance 

Testingii

Turbines 

and 

Substations

IECRE OD-502

IECRE OD-501

DNVGL-SE-0074

DNVGL-SE-0441

ISO 9001

ANSI/International Electrical 

Testing Association (NETA) 

Acceptance Testing 

Specifications (ATS) 

CSA SPE-1000-13

NFPA 79

Certification per OD501&2 should be done by 

an IECRE-accepted 

renewable energy 

certification body). 

C-1 Comments

• In BSEE’s preliminary assessment, the following standards are acceptable: DNV, CSA, or ANSI/NETA standards. However, one industry OEM believes 

further assessment is needed.

• BSEE recommends that developers conduct tests on electrical equipment to determine if it is fit for service before going live. This is routinely being 

done by the industry. OEMs indicate that they do routinely carry out operational tests of wind turbine generators at the factory, including 

generator and converter operation and operation of yaw motors fans, the pitch system, and so on. 

• Standardized precommissioning and commissioning processes are also followed to ensure safe operation of all systems before startup. Also, service 

manuals cover checks during lifetime. These manuals and checklists are required and reviewed as part of type certification according to IECRE OD501.

• NFPA 79 has been added because it includes verification testing.

Ref Category Relevance IEC IEC and EU 

Directives

United States Certification

B-5 Work on 

Submarine 

Cables

Cable Conseil 

International des 

Grands Réseaux 

Électriques

(International 

Council for Large 

Electric Systems)

(CIGRE) TB 773

IEEE 1727

IEEE 1234

B-5 Comments

• CIGRE B1-115_2018 (conference paper) is also recommended for safe working practices in the presence of induced voltages.

• Consult Association of Diving Contractors International and International Marine Contractors Association for standards related to diving operations 

near high-energy systems including submarine power cables.
127 

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Ref Category Relevance IEC IEC and EU Directives United States Certification

C-2 Wiring 

Methods 

High Voltage

(Submarine 

Cable)

Cable IEC 63026

Not specific to subsea 

cable:

IEC 62067

IEC 60840

IEC 60228

DNVGL-ST-0359

CIGRE TB 490

CIGRE TB 610

CIGRE TB 623

CIGRE TB 784

OSHA 29 CFR1910.269

IEEE C2 (NESC)

The cable systems must 

be covered by an existing 

prequalification test and 

type test that is

witnessed by a 

competent witnessing 

body or performed at an 

independent test 

laboratory.

C-2 Comments

• IEC 63026 is the only internationally recognized standard covering both mechanical and electrical testing specifically adapted for submarine cable 

systems up to 60 kV (Um = 72.5 kV).

• Standards that are not specific to subsea cables should be used in combination with CIGRE TB 490 and CIGRE TB 623, which provide guidance on 

testing for submarine applications. 

• Information in DNVGL-ST-0359 is useful but it provides guidance, not a standard.

• Industry recommends consulting Appendix D4 of CIGRE TB 610 and CIGRE B1-303_2016 (conference paper) for information required to calculate 

the current rating under dynamic loading.
128 

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Ref Category Relevance IEC IEC and EU Directives United States Certification

C-3 Wiring 

Methods 

Medium 

Voltage

(Submarine)

Cable IEC 63026

Not specific to subsea 

cable:

IEC 60840

IEC 60502-2 

IEC 60228

DNVGL-ST-0359

CIGRE TB 490

CIGRE TB 623

IEEE 1120 The cable systems must 

be covered by an existing 

prequalification test and 

type test according to IEC 

63026. See standards for 

the description of the 

range of approvals for 

each of the tests. The 

prequalification test and 

type test must have been 

witnessed by a 

representative of a 

competent witnessing 

body or performed at an 

independent test 

laboratory.

C-3 Comments

• IEC 63026 is the only internationally recognized standard covering both mechanical and electrical testing specifically adapted for submarine cable 

systems up to 60 kV (Um = 72.5 kV).

• Standards that are not specific to subsea cables should be used in combination with CIGRE TB 490 and CIGRE TB 623, which provide guidance on 

testing for submarine applications. 

• Information in DNVGL-ST-0359 is useful but it provides guidance, not a standard.

Ref Category Relevance IEC IEC and EU Directives United States Certification

C-4 Wiring 

Methods

Low Voltage

(Substation 

and Wind 

Turbine)

Substations

Turbines

and Cable

DNVGL-ST-0359

BS 7671

Norme Francaise (NF) C15-

100

DIN Verband der 

Elektrotechnik (VDE) 0276-

620

EU Directive: 2009/104/EC

EU Directive: 2006/42/EC

NFPA 70 (NEC)

NFPA 70E

UL 1277

29 CFR 1910.305

ANSI/NEMA WC 71/Insulated 

Cable Engineers Association 

(ICEA) S-96-659

ANSI/NEMA WC 70/ICEA S-95-

658

C-4 Comments

• DNVGL-ST-0359 is an acceptable standard because it directly relates to the offshore wind industry. 

• The following standards are also acceptable: ANSI, NEMA, ICEA, BS, EU Directive, UL, and DIN.
129 

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Ref Category Relevance IEC IEC and EU Directives United States Certification

C-5 Wiring 

Methods

(Marine 

Shipboard 

Cable)

Cable IEC 60092-353 BS 6883

ISO 29400

IEEE 1580

UL 1309

Military Specification MILDTL-24643C

MIL-DTL-24640C

CSA C22.2 No. 245

Cables should be listed as 

a marine shipboard cable 

by an NRTL. 

C-5 Comments

• All of the listed standards are acceptable.

• However, so far there are no shipboard cables on any offshore wind power plants.

Ref Category Relevance IEC IEC and EU Directives United States Certification

C-6 Cable 

Flammability 

Testing

Cable IEC 60332-1-2

IEC 60332-3-22

CIGRE TB 720

EN 61034-2 (or IEC 61034-

2-2005) for smoke visibility

API Recommended Practice 

(RP) 14f

IEEE 1202

 UL 1581 UL 1685

C-6 Comments

• All of the listed standards are acceptable.

• Some industry representatives recommend using API RP 14f to identify fire protection needs and CIGRE TB 720 to select fire protection methods. 

Others disagree.

• Note that the United States and Europe prioritize different hazards. Common practice in the United States suggests greater concern about smoke 

than the toxicity of emissions. U.S. manufacturers make cables with halogen, whereas European designs are halogen-free.

Ref Category Relevance IEC IEC and EU Directives United States Certification

C-7 Harmonics Turbines 

and 

Substations

IEC 61000-3-2 IEC 61000-

4-7 IEC 61000-4-15 

IEC 61000-4-30

EN IEC 61000-3-2

EN 50160

IEEE 519

C-7 Comments 

• The prevention of harmonics needs to be discussed between the offshore wind farm developer and grid owner.

• Requirements are typically set by the transmission system operator/grid owner.
130 

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Ref Category Relevance IEC IEC and EU Directives United States Certification

C-8 Systems of 

Insulating 

Materials

Turbines IEC 61857-31

IEC 60721-1 

IEC 60071-1&2

IEC 60664-1&3

IEC 60085

UL 1446

IEEE 1776

Certification should be 

carried out in 

accordance with the 

design standards used 

and employ NRTL 

approval if called for 

in those standards.

C-8 Comments

• The U.S. and/or IEC standards are acceptable. For example, Intertek certifies wind turbines to both IEC and U.S. standards that address systems of 

insulating materials.

• IEC 60071-1 and 60071-2 (applicable for general requirements on insulation coordination), and, for low voltage, 60664-1 and 60664-3, have been 

added per industry recommendation.

• The overriding standard for evaluation of insulation systems is IEC 60085. It has been added above.

• Regarding certification, design toward electrical safety standards is covered as part of type certification. Some participants recommend against a 

requirement for repeated testing and/or evaluation by a NRTL. Others recommend the following approach: If using U.S. codes and regulations that 

require NRTL certification, then a NRTL should be used to certify. If using IEC standards, then tests with alternative accredited labs for those 

standards may be acceptable.

Ref Category Relevance IEC IEC and EU Directives United States Certification

C-9 Uninterrupt

-able Power 

Supplies

Turbines 

and 

Substations

IEC 62040-1

IEC 61056-1 

IEC 60896-21

BS EN 62040-5-3

BS EN 62040-1

UL 1778 UL 62109-1 

UL 6141

CAN/CSA-C813.1 

CAN/CSA-C381.2

CSA-C22.2 No. 60896-21

IEEE 1106 IEEE 1184 

IEEE 1115

NECA NEIS 411

Certification should be 

carried out in 

accordance with the 

design standards used 

and employ NRTL 

approval if called for 

in those standards.

C-9 Comments

• The IEC and BS EN standards are acceptable. The UL 6141 standard references both as compatible.

• Regarding certification, uninterruptable power supply (UPS) systems are provided by the supplier with type-test certification and documentation. 

Some participants recommend against a requirement for repeated testing and/or evaluation by an NRTL. Others recommend the following 

approach: if using U.S. codes and regulations that require NRTL certification, then an NRTL should be used to certify. If using IEC standards, then 

tests with alternative accredited labs for those standards may be acceptable.
131 

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Ref Category Relevance IEC IEC and EU Directives United States Certification

C-10 Slip Rings Turbines IEC 60204-1

IEC 60364-1 

IEC 60664-1 

AS 60204-1 UL 508

UL 347

UL 6141

C-10 Comments

• The IEC slip rings standard IEC 60204-1 is acceptable. The UL 6141 standard accepts either IEC 60204-1 or UL 508 compliance.

• UL 6141 explains that testing of the slip ring must consider the ratings/certifications of upstream overcurrent protection. A slip ring evaluated to UL 

508 may not be compatible with upstream equipment evaluated to IEC 60204-1.

• IEC 60364-1 and IEC 60664-1 could be considered applicable. IEC 60664-1 focuses primarily on electromagnetic compatibility (EMC) requirements, 

whereas IEC 60364-1 covers more general electrical requirements. These have been added to the above list per industry suggestion.

Ref Category Relevance IEC IEC and EU Directives United States Certification

C-11 Alternators,

Generators, 

and 

Motors

Turbines IEC 60034 Series

IEC 60034-1 IEC 60034-2-1 

IEC 60034-2-2 

Note: ANSI is harmonizing the 

ANSI C50 series with IEC 

60034

ISO 281 UL 1004 Series

UL 4143 UL 1004-1&4 

UL 6141

ANSI/NEMA MG 1 

NEMA MG 2

ANSI C50 series

IEEE 1310

Certification should be 

carried out in 

accordance with the 

design standards used 

and employ NRTL 

approval if called for 

in those standards.

C-11 Comments 

• The IEC Alternators, Generators, and Motors series of standards are acceptable. The UL 6141 standard accepts compliance with either the UL 1004 

series or IEC 60034 series.

• UL 6141 explains that testing of the item must consider the ratings/certifications of upstream overcurrent protection. An item evaluated to UL 1004 

may not be compatible with upstream equipment evaluated to IEC 60034.

• Regarding certification, generators go through extensive component certification testing. Motors are provided by the supplier with type-test 

certification and documentation. Some participants recommend against a requirement for repeated testing and/or evaluation by an NRTL. Others 

recommend the following approach: if using U.S. codes and regulations that require NRTL certification, then an NRTL should be used to certify. If 

using IEC standards, then tests with alternative accredited labs for those standards may be acceptable.
132 

This report is available at no cost from the National Renewable Energy Laboratory at www.nrel.gov/publications.

Ref Category Relevance IEC IEC and EU Directives United States Certification

C-12 Cable 

Testing

Cable IEC 60230

IEC 60229

IEC 60287

IEC 60811-501

CIGRE TB 303

CIGRE TB 490

CIGRE TB 623

CIGRE TB 722

ICEA P-32-382 

ICEA P-45-482

ICEA T-24-380 

ICEA T-31-610

ICEA T-32-645 

ICEA T-34-664

Association of Edison 

Illuminating Companies (AEIC) 

CS8 AEIC CS9

C-12 Comments

• Note that this testing does not apply to submarine cables.

Ref Category Relevance IEC IEC and EU Directives United States Certification

C-13 Wiring 

Within the 

Turbine

Turbines IEC 60364-5-52

IEC 60364-1 

IEC 60204-1 

BS 7671 NFPA 70 (NEC) NFPA 79

UL 6141 UL 508

UL 2277 Outline

UL 1651 UL 1072

C-13 Comments

• Both the IEC and U.S. standards are acceptable. As required by UL 6141, the OEM needs to state which set of standards is used and remain 

consistent in the design.

• Note that the requirements for wiring in Section 4.2 of UL 6141 address wiring design, installation, and marking. NFPA 70 or IEC 60364-5-52 align 

with UL requirements.

• Industry recommends that wiring be fully documented in electrical diagrams made available to technicians. This could be beneficial to addressing

differences between the NFPA and IEC; for example, wire color coding.

• Industry recommends using the NFPA standards, and that they be acceptable (technicians will be trained to these standards).

• Note that these standards apply only for voltages under 1,000 volts alternating current (VAC) (1,500 VDC).
133 

This report is available at no cost from the National Renewable Energy Laboratory at www.nrel.gov/publications.

Ref Category Relevance IEC IEC and EU Directives United States Certification

C-14 Surge 

Protection/ 

Suppression

Component

Turbines 

and 

Substations

IEC 61643-11

IEC 60099-4 

BS DD CLC TS 50539-22

DIN CLC/TS 50539-22

UL 1449

IEEE C62.23

IEEE C62.21

C-14 Comments

• In BSEE’s preliminary assessment, the UL and IEEE standards, or the IEC standards, are acceptable. However, one industry OEM believes further 

assessment is needed to determine which IEC standards are compatible with U.S. standards.

Ref Category Relevance IEC IEC and EU Directives United States Certification

C-15 Pitch, Yaw, 

Other 

Control 

Panels

Turbines IEC 61400-3 EN IEC 61400-3

DS/EN 61400-3 

UL 508A

CAN/CSA-C22.2 No 14

CAN/CSA-C61400-3 

Certification should be 

carried out in 

accordance with the 

design standards used 

and employ NRTL 

approval if called for 

in those standards. 

C-15 Comments

• In BSEE’s preliminary assessment, the following standards are acceptable: UL 508A, CAN/CSA C22.2 No 14, and CAN/CSA C61400-3. However, one 

industry OEM believes further assessment is needed to determine which IEC standards are compatible with U.S. standards.

• Note that Intertek certifies wind turbines to the above standards.

• Consider splitting this category into separate topics, given its broad coverage. Control panels are designed to comply with numerous IEC and ISO 

standards on both electrical safety, ingress protection, EMC, adequate working space, guarding, and so on. 

• Industry recommends including relevant IEC/ISO standards among acceptable standards.

Ref Category Relevance IEC IEC and EU Directives United States Certification

C-16 Gearboxes Turbines IEC 61400-4 DS/EN 61400-4

OVE/ONORM EN 61400-4 

DIN EN 61400-4 

BS EN 61400-4 

ANSI/American Gear 

Manufacturers 

Association/American Wind 

Energy Association 6006-A03

UL 508

UL 73

C-16 Comments

• Any of the above standards are acceptable for gearboxes.
134 

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Ref Category Relevance IEC IEC and EU Directives United States Certification

C-17 Wind 

Turbine 

Tower 

Elevators

Turbines EN 81-44 (in development)

2006/42/EC (machinery)

EN 1808

CSA B44.8/American Society 

of Mechanical Engineers 

(ASME) A17.8

ASME A17.8

ANSI/ASSP A10.4

C-17 Comments

• In BSEE’s preliminary assessment, any of the above standards are acceptable for wind turbine elevators. However, one industry OEM believes 

further assessment is needed to determine which EN standards are compatible with U.S. standards.

• EN 1808 has been added to the listing per industry recommendation.

Ref Category Relevance IEC IEC and EU Directives United States Certification

C-18 Hoist, 

Winch, and 

Cranes

Turbines IEC 60204-32 AS 1418.2 AS 2550.1

BS EN 14492-1 

EN 13001-1&2&3

IEC 60204-32

EN 12999

EN 14492-1&2

DIN 15400

EN 12385-4 

EN13411-6 

EN1993-6

UL 1340

C-18 Comments

• UL 1340 is an acceptable standard.

• Some industry representatives recommend including the following as acceptable standards: EN 13001-1, EN 13001-2, and EN 13001-3 for general 

crane requirements; IEC 60204-32 for electrical requirements toward hoisting machines; EN 12999 for specific requirements toward hydraulic 

powered cranes; EN 14492-1 and EN 14492-2 for winches and hoists; DIN 15400 for lifting hooks; EN 12385-4 and EN 13411-6 for steel wire ropes; 

and EN 1993-6 for crane rail systems.

• All of these additional standards have been added to the above list.

• However, one industry OEM believes further assessment is needed to determine which EN standards are compatible with U.S. standards.
135 

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Ref Category Relevance IEC IEC and EU Directives United States Certification

C-19 Lighting Turbines 

and 

Substations

BS EN 12464-2

Proposed additions for 

consideration:

EN 50308

EN 12464-1 

EN1838

EN1837

OSHA 29 CFR 1926.26

OSHA 29 CFR 1926.56

ANSI/IES RP-7-17

IEEE C2 (NESC) - minimum 

illumination intensities for 

different areas of operation

UL 1598

Internal lighting 

fixtures – NEMA 4 

protection (IP 65 can 

be accepted)

External lighting 

fixtures – NEMA 6 

protection (IP 67 can 

be accepted)

C-19 Comments

• In BSEE’s preliminary assessment, any of the originally listed standards are acceptable for lighting. Proposed additions need to be considered.

• Some industry representatives recommend expanding the list of standards to include EN 50308, which is specific to wind turbines; EN 12464-1 for 

indoor lighting and EN 1838 for emergency lighting; and EN 1837, as the more general lighting standard.

• However, one industry OEM believes further assessment is needed to determine which EN standards are compatible with U.S. standards.

• Another recommended addition is UL 1598, the safety standard for luminaires. It is added to the above list.

Ref Category Relevance IEC IEC and EU Directives United States Certification

C-20 Illumination 

Levels for 

Emergency 

Evacuation 

Turbines 

and 

Substations

Australian Standard/New 

Zealand Standard (AS/NZS) 

2293.1

EN 50308

EN 1838

NFPA 110

NFPA 111

NESC

C-20 Comments

• The NFPA and AS/NZS standards listed above are acceptable. 

• EN 50308 and EN 1838 have been added to the list per industry recommendation.
136 

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Ref Category Relevance IEC IEC and EU Directives United States Certification

C-21 Emergency 

and 

Standby 

Power 

Systems

Turbines 

and 

Substations

IEC 62034

IEC 61892-2 

IEC 62040-1&2&3&4

CSA-C282

CSA-C22.2 No. 141

NFPA 110

NFPA 111

C-21 Comments

• The CSA and NFPA standards are acceptable for emergency and standby power systems.

• Some industry representatives recommend including the following as acceptable standards: IEC 62040-1, IEC 62040-2, IEC 62040-3, and IEC 62040-

4, which are leading standards for UPS design and testing. These have been added to the above list. However, this recommendation is not 

supported by all.

Ref Category Relevance IEC IEC and EU Directives United States Certification

C-22 Power 

Sockets and 

Plugs

Turbines 

and 

Substations

IEC 60309 UL 498

NFPA 70 (NEC)

Receptacle NEMA 4X 

protection. 

C-22 Comments

• The UL, NFPA, and NEMA standards listed above are acceptable.

• Industry recommends adding IEC 60309, which would be used for special OEM equipment operating at higher voltages (400 V, 690 V); 120-V 

sockets and plugs are likely to use NEMA 5-20R.

• Occasionally, European outlets have been mistakenly installed in some turbines for simple 110-V circuits.

Ref Category Relevance IEC IEC and EU Directives United States Certification

C-23 Cable Trays Turbines 

and 

Substations

IEC 61537

IEC 60364-5-52

DS/EN 61537

BS EN 61537

UL 2277 Outline

UL 6141

NEMA VE 1

NFPA 70 (NEC) Art.320

CSA C22.2 No. 230 & No.126.1

C-23 Comments

• In BSEE’s preliminary assessment, any of the standards listed above are acceptable. However, one industry OEM believes further assessment is 

needed to determine which EN standards are compatible with U.S. standards.

• Note that routing of cables can be done according to IEC 60364-5-52. This may relate to the configuration of cable trays, but not necessarily to the 

cable trays themselves.
137

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Ref Category Relevance IEC IEC and EU Directives United States Certification

C-24 Cable Cleats 

for 

Electrical 

Installations

Turbines 

and 

Substations

IEC 61914

Proposed additions:

IEC 61238-1-1&2&3

BS EN 61914

DS/EN 61914

DIN EN 61914

UL 1565

UL 6141

NFPA 70

C-24 Comments

• In BSEE’s preliminary assessment, the standards originally listed above are acceptable. However, one industry OEM believes further assessment is 

needed to determine which IEC standards are compatible with U.S. standards.

• Industry recommends adding IEC 61238-1-1, IEC 61238-1-2, and IEC 61238-1-3 to the list of acceptable standards.

Ref Category Relevance IEC IEC and EU Directives United States Certification

C-25 Cathodic 

Protection

Turbines 

and 

Substations

DNVGL-RP-B401

DS/EN 12473

EN 12495

ISO 12473

BS/EN 13173

National Association of 

Corrosion Engineers (NACE)

RP-01

C-25 Comments

• Any of the standards listed above are acceptable.

Ref Category Relevance IEC IEC and EU Directives United States Certification

C-26 Grounding 

and 

Bonding

Turbines 

and 

Substations

IEC 60364-5-54

IEC 60204-1

IEC 60364-5-4

IEC/BS EN 62305-3 NFPA 70 (NEC)- Art. 250

CSA C22.2 No. 0.4 & No. 41

UL 467

IEEE 3003.2

C-26 Comments

• In BSEE’s preliminary assessment, the following standards are acceptable: NFPA 70, CSA, UL, and IEEE. However, one industry OEM believes further 

assessment is needed to determine which IEC standards are compatible with U.S. standards.

• IEC-60204-1 has been added per industry recommendation.

• Industry recommends adding IEC 60364-5-4 to the list of acceptable standards because it is part of the design basis and is well-established in the industry.

i NOTE: Arc flash does not apply only to transformer and high-voltage equipment, as low-voltage circuits have the potential for arc flash as well. Protection 

against electrical shock and arc flash are not equivalent.

ii NOTE: ANSI/NETA ATS-2017 (Standard for Acceptance Testing Specifications for Electrical Power Equipment and Systems) is an acceptable method for 

ensuring electrical equipment and systems are operational, are within applicable standards and manufacturer’s tolerances, and are installed in accordance 

with design specifications prior to going live.