Source: https://www.scribd.com/document/95260038/A-Del
Timestamp: 2017-03-26 10:15:13
Document Index: 442196802

Matched Legal Cases: ['art 4', 'art 4', 'arts 143', 'art 31', 'art 2', 'art 31', 'art 2', 'art 144', 'art 143', 'art 4', 'art 4', 'art 4', 'art 2', 'art 143', 'art 144', 'art 4', 'art 1', 'art 31', 'art 3']

A Del | Voltage
BrowseInterestsStay InformedCareerPersonal GrowthFiction & BiographiesHealth & FitnessLifestyleCultureBrowse byBooksAudiobooksNews & MagazinesSheet MusicBrowse allUploadSign inJoinMinistry of Defence INTERIM Defence Standard 02-607Issue 1 Publication Date 6 July 2001
Guide to the Design of a Medium Voltage Distribution System in HM Surface Ships and Submarines
AMENDMENTS ISSUED SINCE PUBLICATION AMD NO DATE OF ISSUE TEXT AFFECTED SIGNATURE & DATE
Revision Note This is the first Issue of this Standard. Historical Record This is the first Issue of this Standard.
MR J KNOTT STAN SPM 5 D/DStan/69/2/607/Def Stan 02-607 Issue 1
Defence Standardization Rm 1138 Kentigern House 65 Brown st Glasgow G2 8EX
Direct line: Switchboard: Facsimile: e-mail: 0141 224 2332 0141 224 2531 0141 224 2503
pdgst5@udawn.dpa.mod.uk or j.knott@dstan.mod.uk
Your Ref: Our Ref: DStan/69/2/603 Date:
INTERIM DEFENCE STANDARD (FORMER NES) - INVITATION TO COMMENT Defence Standard Number: 02-607 (NES 607) Issue 1 INTERIM Title: Guide to the Design of a Medium Voltage Distribution System in HM Ships and Submarines The above Defence Standard has been published as an INTERIM Standard. Interim Defence Standards are suitable to be called up in contracts and have the same legal status as full standards. In addition this standard is considered to be technically correct, but it is necessary to use it and get user feed back on its suitability before reissue as a full standard. Interim Standards are reviewed after a year and where necessary amended. They are then normally reissued as full standards. Users are therefore invited to forward any information or comment and experience on the application of this standard. These will be collated and forwarded to the sponsor to aid amendment and issue of a final version. The purpose of this form therefore is to solicit any beneficial and constructive comment that will assist the author and/or working group to review the INTERIM Standard prior to it being converted to a full Standard. Comments are to be entered below and any additional pertinent data which may also be of use in improving the Standard should be attached to this form and returned to the above address. No acknowledgement to comments received will normally be issued. NAME: J KNOTT SIGNATURE:
BRANCH: PDG/DSTAN SPM 5
1. Does any part of the Standard create problems or require interpretation:
YES NO If “yes” state under section 3: a. the clause number(s) and wording;
AN EXECUTIVE AGENCY OF THE MINISTRY OF DEFENCE
. 2....................... Comments. Should you find my/our comments at variance with the majority................. I/We agree that this Draft Standard.. Telephone number: Submitted by (print or type name and address) Date: Our Ref:
DSTAN Form 42N
............ when published in final form will cover my/our requirements in full............ Is the Defence Standard restrictive: YES NO If “yes” state in what way under section 3...... Signature..... general or any requirement considered too rigid: Page Clause Comments Proposed Solution
4.. I/we shall be glad of the opportunity to enlarge upon them before final publication............. subject to my/our comments being taken into consideration................. the recommendation for correcting the deficiencies.b.Representing..
INTERIM DEFENCE STANDARD 02–607 (NES 607)
This Defence Standard is authorized for use in MOD contracts by the Defence Procurement Agency and the Defence Logistics Organization
Published by: Defence Procurement Agency An Executive Agency of The Ministry of Defence Directorate of Standardization Kentigern House 65 Brown Street Glasgow G2 8EX (i)
INT DEF STAN 02–607 / ISSUE 1 (NES6070
4. This NES must also be applied in conjunction with the Statement of Technical Requirements (STR) for any given project. Therefore this NES must be applied in conjunction with NES 532. This NES covers similar requirements to those of NES 532. . Similarly. This NES will provide guidance and technical requirements and the STR will include additional technical requirements. NOTE: MV is defined as any ac voltage between 1 kV and 15 kV 2. Detailed requirements which are the same as those for Low Voltage (LV) systems are not duplicated in this NES. This Naval Engineering Standard (NES) provides guidance for the design and operation of Medium Voltage (MV) ac electrical power systems for HM Surface Ships and Submarines.
.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
1. the STR will state the applicability of the various general standards and specifications such as DEF STAN 59 41 for Electromagnetic Compatibility (EMC) limits and NES 1004 for environmental conditions.
INT DEF STAN 02–607 / ISSUE 1 (NES 607)
Any significant amendments that may be made to this NES at a later date will be indicated by a vertical sideline. relevant to each particular tender or contract. in connection with which it is issued.
12. The Crown reserves the right to amend or modify the contents of this NES without consulting or informing any holder. This Naval Engineering Standard (NES) is sponsored by the Defence Logistics Organisation (DLO). reproduced or published without written permission of the MOD. This NES is the property of the Crown. 2. including related documents.
13. users are responsible for their correct application and for complying with contractual and any other statutory requirements. and those directly applicable to a particular contract are to be dealt with using existing departmental procedures.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
FOREWORD Sponsorship
10. Compliance with an NES does not of itself confer immunity from legal obligations.
9. Deletions will be indicated by 000 appearing at the end of the line interval. 6. It is not to be released. Enquiries in this connection may be made to the authority named in the tender or contract. 5. When this NES is used in connection with a MOD tender or contract.
. Ministry of Defence (MOD). and its contractors in the execution of contracts for the MOD. liability resulting from negligence) for any loss or damage however caused when the NES is used for any other purpose. the user is to ensure that he is in possession of the appropriate version of each document. dated October 2000 to reflect changes in departmental nomenclature and the changes to technical requirements. or submission of the tender.
11. This NES has been reissued at Issue 1. When NES are incorporated into MOD contracts. reference in this NES to approval.
Conditions of Release General
8. No alteration is to be made to this NES except by the issue of an authorized amendment. This document is Crown Copyright and the information herein may be subject to Crown or third party rights. If it is found to be unsuitable for any particular requirement. This NES has been devised solely for the use of the MOD. To the extent permitted by law. Proposals for amendments that are not directly applicable to a particular contract are to be made to the publishing authority identified on Page (i). approved. Unless otherwise stated. MOD is to be informed in writing of the circumstances. Any user of this NES either within MOD or in industry may propose an amendment to it. authorized and similar terms means by the MOD in writing. the MOD hereby excludes all liability whatsoever and howsoever arising (including but without limitation. Unless otherwise authorized in writing by the MOD it must be returned on completion of the contract.
its complement or third parties.
15. Defence Procurement Agency. Category 3. Prime Contractors are responsible for supplying their subcontractors with relevant documentation. b. Category 1. its complement or third parties. its systems or equipment. Operational performance of the vessel. Through life costs and support. Kentigern House. Current support practice. In the tender and procurement processes the related documents listed in each section and Annex A can be obtained as follows: a. This NES may call for the use of processes. W4 4AL.
19. An Executive Agency of the Ministry of Defence. G2 8EX. together with the sponsoring Directorate and the Tender or Contract Sponsor.
18. 16. If not applied may have a Minor affect on the following: MOD best practice and fleet commonality.
All applications to Ministry Establishments for related documents are to quote the relevant MOD Invitation to Tender or Contract number and date. London. taking into account the policy stipulated in JSP 430 MOD Ship Safety Management System Handbook. This NES has been written. Corporate Experience and Knowledge. Directorate of Standardization. 65 Brown Street. If not applied may have a Critical affect on the following: Safety of the vessel.
b.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
Categories of NES
14. Tender or Contract Sponsor to advise. those quoted may not necessarily be exhaustive. standards and drawings. and is to be used. including specifications. Where attention is drawn to hazards. Glasgow. substances and/or procedures that may be injurious to health if adequate precautions are not taken. It refers only to technical suitability and in no way absolves either the supplier or the user from statutory obligations relating to health and safety at any stage of manufacture or use. its systems or equipment.
17. Operational performance of the vessel. If not applied may have a Significant affect on the following: Safety of the vessel. 389 Chiswick High Road. The Category of this NES has been determined using the following criteria: a. Category 2.
(There is no relevant information included)
. c. British Standards British Standards Institution.
Defence Standards & Naval Engineering Standards
. . . . . . . . . . . . . . . . . .1 2. .6 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5. . . . . . . . . . . . . . . . . . . . . . . .2 1. . . .5 1.2 1. . . . . . . . . . . . . . Rectifiers . . . . . . . .6. . . . . . . . . . . . . .2 SECTION 2. . . . . . . . . Equipment Hardware Constraints . . . . . . . . . . . .6. . . .5 1. . . . Surges and Sags . . . . . . . . . . . . . . . . .3 1.8 Table 1. . . . . . . . . Load Balance . . . . . . . .1. . . . . . . . . . . . . . . . .5. . . . . . . . . .1 1. . . . . . . . . . . . . . . . . . . . . . . .5.2 2. . . . . .4 1. . . . . . . . . . . . . . . . . . Responsibilities for Safety . . . . . . . . . . . . . . 1. . . . . . Starting and Inrush Currents . . . . . . . . .4 1. . . . . . . . . . . . . . . . ac System Power Quality Factors . . . . . . . . . . . . .1 2. . . 2. . . . . .3 2. . . . . . . . . . . . . . . . . . . . . . . . . . . Variation of the Electrical Safety Rules . . Voltage and Current Line–to–Line Imbalances . . . . . . . . . . . . . . . . . . . . . .6.1 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (vi) Additional Information . . (i) SCOPE . . . . . . . . . . . . . . . . . . . . . .7 1. . . .2 2. . . .3 1. . . . . . . . . . . . . . . .4 1. . . . . . . . . .6 PERFORMANCE SPECIFICATION . . . . .1 2. . . . . .5 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 2. . . . . Users’ Constraints . . . . . . . . . . . . . .1 1. . . . . . . General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Susceptibility to Waveform Quality . .1 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3. . . . . . . . . . . . . . . . . . . . . . . . . . Compliance with DEF STAN 61-5 . . . . . . .2
. . . . . . . . . . . . . . Contributors to Waveform Quality . . . . . General . . .1 2.2 Table 1. . . . . . . . . . . . . . (vii) 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .INT DEF STAN 02–607 / ISSUE 1 (NES 607)
CONTENTS Page No TITLE PAGE . . . . . . . . . . . . . . . . . . . (v)
Conditions of Release . . . . . . . . . .6 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 2. . . . . . . . . . . . . . . . .7. .4 1. . . . . . . . . . . Scope and Allocation . . . . . Modulation (Flicker) . . .2 2. . . . .4 1. . . . . . . . . . . .7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 1. . . . . . . . . (vi) Health and Safety . . . . . . . . . . . . . . . . .4 1. Electrical System Schemes which may Require Medium Voltage . . . . . . . . General Safety Precautions . . . . . . . . . .1 2. . . Voltage Ripple . . . . . . . . . . . .2 1. . . . . . . . . . . . . . . . . . . . . .1 2. . . . . . . . . . . . . Quality of Power Supply Limits . . . . . . . . . . . . . . . . . . . . . . . . .1 1. . . . . . . . . . . .5 1. .3 1. . . . . . . . . . . . . . . . . . Equipment Performance Constraints . . . . . . . .6 1.8 2. . . . . . . . . .1 1. . . . .1. .2 1. . Objections .1. . . . . . . . . Quality of Medium Voltage Power Supplies . .1. . . . . . . . . . .7 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . NATIONAL/INTERNATIONAL REGULATIONS . . . . . . . . . . . (v) Categories of NES . . .7 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Users’ Constraints . . . . . . . . . . . . . . . . Notches . . . . . . (vii) SECTION 1. . . .4 2. . . . . . . . .3 1. . . . . . . . . . . . . . . . . . . . . . . . .6. . . . . . . . . . (vi) CONTENTS .1 1.1 1.8 1. . . . . . . . . . . . . . Spikes. . . . . . . . . . . . . . . . . . .1 1. . . . . . . . . . . . . .3 1. . . . . . . . . . . . . (v) Sponsorship . . . . . . Harmonics . . . . . . . . . . . .6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Safety .6 1. . . . . . . . . . . . . .6. . . . .1. . . . . . (iii) FOREWORD .6 1. . . . . . .3 1. . . . . (v) Related Documents . . . . . . . . . . . Statutory Safety Requirements . . . . . . . . . . . . . .2 1. . . . . . . . . . . . . . .
. .2 Table 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 3. . . 2. . . . . . . . . . . . . . 2.9 3. . . . . . . .7. 2. . . . . . . 3. . . .2 Description . . . . . . . .7 Flash Hazard . . 3. .10 (viii)
. . . . . . . . . . . . . . . . . . . . . .2 3.7 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2. . . . . . . . . . . . . . . . . . . . . . 3. . . . . 3. . . . . . . .2 3. . . . . . . . . . . . . . . .3 Training . .4 Medium Voltage Warning Signs . . . . 3.1 2. . . . . . . . . .5 2. . . . . . . . . . . . . . .8 Unearthed Neutral Systems . . . .2. . . .2 3. . . . . . 2. . . . . . . . . .3 Safety Terminology . . . . . 2. . . . .1. . . . . . . . . . . . . 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 Parallel Feeders . . . . . . . . . . . . . . . . . . . . . .3 Figure 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.4. . . . . . . . . . . 3. . 2. . . . . . . .10 3. . . . . . . . . . . . . . . . .7. . . .1 3. . . . .1 Medium Voltage Systems which Feed Electric Propulsion Systems . 3. . . . . . . . . .7 Factors Not Significant . . . . .4. . .5 Parallel Feeders . 2. . . . . . . 3.6 Considerations in Selecting Earthing Method . . . . . . .3 2. . . . . . . . . . . . . . . 3. . . . . . . . . . . . . . . . . . . .6 Earthing Policy for Medium Voltage Systems in HM Surface Ships and Submarines . . . .3 Review . . . . . . . . . . . . .2 2. . . . . . .10 Equipment Selection . . . . . . .4 Compartment Notices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 3. . . . . . . . . 3. . . . . . . . . . . . . . . . 3. . . . . 3. . . . . . . . . . .2 3. . . . . . . . . . . . . . . . . .4 Authorising Engineer . . . . . . . .7 Significant Factors . 3. . . . . .5. . . . . . . . . . . . . . . . . . . .2. . . . . . . . . . . . . .2. .1 Medium Voltage Electrical Power Requirements . . . . . . . . . . . . . . .11 3. . . . . . .2 2. . . . . .6 Protection Against Contact Above 1 kV . . . . .4 Danger Notice .3 2. . . . . . . . . . . . . . . . . .12. 3. . . 2. . . . .6 3. . . . . . . . . . .1. . . . . . . . . . .5. . . . . . . . . . . .3 2. . . . . . . . .3 3. . . . . . . . . . .3 Authorised Person . . . . . . . . . . . . . . .3 Authorised Person in Control . . . . . . . . . . . 2. . . . . . . . . . . . . . . . 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 3. . . . . . . . . . . . . . . . . . .INT DEF STAN 02–607 / ISSUE 1 (NES 607)
2. . . . . 2. . . . . . . . . . . . . . . . . . . .6 Direct Contact . . . . . . . . . . . 3. . . . . . . 3. . . . . . . . . . . . . . . . . . . . . . .7 Preferred Method . . . . . . . . .5 2. . . . . . . . . . . . . . . . . . .2 3. . . . .4 Co-ordination of Inverse Time Over-current Relays . . . . .7. . . . . . . . . . . . . . . .3 General . . . .10 General . 3. . . . . . . . . . .4. . . . . . . . . . . . . . .2 3. . . . 3. . . . . . . . . . . 2.4 Caution Notice . . . .4 Figure 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5. . . . . .1 3. .9 Maintenance Earthing . 3. . . . . . . . . .3 Protection . . . . . . . . . . . . . . . . 3. . .5. . .1 2. .1 Medium Voltage Systems which do not Supply Electric Propuslion Systems .1 3. . . . . . . . . . . . . . . . . . . . 3. . . . . . . . . . . . . .1 2. . . . . . .4. . . . . . . . .4 3.5 MILITARY STANDARDS/REQUIREMENTS . . . . . . . . . . . . .5. . . . . .1
Page No Safety by Design . . . . . . . . . . . . . . 3. . . . . . . . . . . . . . . . . . .2 2. .2 Safety Rules . . . 3. . . 2. . . . . . . . . . . . . . . . . 3. . . . . . . . . . . .12 3. 2. . . . . . . . . . . . .5 First Aid . . . .4 Competent Person . . . . . . . .4.4 2.4 SECTION 3. . . . . . . . . .4 2. . . . . . . . . . . .2. . .8 High Impedance Neutral Earthing . . . . . .10 Further Earthing Requirements . . . . . .4 General . .3 Current Protection . . . . . . . . . .1 Table 3. .3 2. . . . . . . . . . 3. . . . . . . . . . . . . . . 3. . .1 Load Chart for a Medium Voltage Electrical System which Feeds Propulsion Motors . . . . . . . . . . . . . . . . . . 3. . . . . . . . . . . . . .7. . . .2 2. . . . .6 Indirect Contact . . . . . . . 2.5 3. . . . .8 3. . . . . . . . . . . . . . . .2 Load Chart for Pulsed Loads on a Medium Voltage Electrical System . . . . . . . . . . .5. . . . . 2.3 Voltage Protection . .
18 3. . . .11 HM Surface Ships . . . . . . . . . . . . .3 Sensing Circuits . . 3. . . . . . . . . . . . . . . . . . 4. . . . .7 Issues Specific to Medium Voltage Supplies . . . . .11 Submarines . 3. . .2 4. . . . . . 3. . . .12 Machines . .12 Transformers . . . . . . . . . . . . . .4. . . . .13 4. . . . . . . . . .7 4. . .13. . . . . . . . 3. .14. . . . . . . . . . . . . . . . . . . . . . . . . . . .9. . . . . . . . . . . . . . . . . . .1 4.1 4. . . . 4. . . . . . . . . . . . . . . . . 4. . . . . . . . . .12 Creepage and Clearance . . . . . . . . . . . . . . . . .2 4. .2 Requirements . . . . .3. . . . . . . . . . 4. . .3 Safe Operating Procedures . . . . . . . .1 Main ac Electrical Power Supply and Distribution . . . . . . . .11 Bulkhead Penetrators . . . . . 4. . . . . .11 Switchboards . . . . .3 3. . 4. . . . . . . 4. . . . . .11 4. . . .5. . . . . . . . . . . . . . .2 3.17 3. . . . .1 General . . . . . . . . . . . . . . . . . . . . . . . .1 3. . . . . . . .3 4. .10 Table 4. . . . . . . . . . . . . . . . . 4. . . . . . . . . . . . . 4. . . . . . . . . . . . . . . . . .13. . . . . . . . . . . . . 4. 4. . . . . . . . . . . . . . . . . 4. . . . . . . . . .8 Fault Level . 3. . . 4. 3. . . . . . . . . . . . . . . . . 4. 4. .19 3. . . . . . . . . . . . . . . . . . . . . . . . 3. . . . . .7 Fault Level Assessment for Medium Voltage Systems . . . . . . . . . . 4. . . . . . .13 Commissioning/Special Test Equipment . .9 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 Other Equipment . . . . . . 3. . . . . . . . 3. . 4. . .1 Interfaces with the Low Voltage Distribution System . .2 4. .1 4. . . . . . . . . . . . . . .13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 Circuit Breakers . . . . . . .1 4. . . . . .13 (ix)
. . . .2 3. . . . . . . . . . . . . .14. . . . . . . . . . . . . . . .1 Figure 4.11 Equivalent Impedance Diagram . . . . . . .6 Table 4. . . . .13 DESIGN REQUIREMENTS GUIDANCE . 4. . . . . . . . . . . . .20. . . . . . . . . . . . . . . . . . . 4. . . . . .20. . . . . . . . 3. . . . . . . . . .2 Table 4. .10 System Considerations . . . . . . . . . . . . . . . . . . . . . . .3 4. . . . . . . . . . . . . . .8 Typical Simple Network . . . . . . . . 4. . . . . . .2 Instrumentation and Control . . . . .16 3. . . . . . . . . . . . . . .6 Provision of Alternative Supplies . . . . 3. . . . .3 Generator Configuration . .INT DEF STAN 02–607 / ISSUE 1 (NES 607)
3. . . . . 3. . .2 3. .12 Medium Voltage Testing . . . . . . . . . . . . . . .3 SECTION 4. . .5. . . . . . . . . . . . . . . . . . . . 4.1 System Configuration . . . . .7 General . . . . . . . . . . . . . . . . . . 4. . .1.6 Integrity Parameter Requirement Format for Medium Voltage System – Miscellaneous Loads . 3. . . . . . . . . . . . . . . . . . . .12 Fuses . . . . .10 Cable Selection . . .1. . . . . 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3. . .12 Oil Filled Components .1 Table 4. 4. . . . . . . . . . . . .1 4. . . . . . . . 3. . . . . . . . .7 Characteristics of System Over-voltages . . . . . . . . . . . . . . . . . .1 4. . . . . . . . .11 Cable Ratings . .12 Medium Voltage Creepage and Clearance . . . .3 General .14 3. . . .3 Power System Integrity . . . .1 3. . . . .4. . . . . . . . . . 4. . . . .1 3. . . . . . 4. . . . . . . . . .5 4. . . . .4 4. . . . . . .2 4. . .13 3. . . . . . . . . . . . . . .21 Table 3. . . . . . . . . . . .13 Standard Insulation Levels . . . . . . . . . . . .12 Insulation Co-ordination . . . . . . . . 4. . . . . . . . . . . . .2 4. . . . . . . . . . . . . . . . . .4 Integrity Parameter Requirement Format for Medium Voltage System – Propulsion and Low Voltage Supplies . . . . . . . . . . . . . . . . . . . . . . . . . 4. . . . . . . . . 4. . . . .4
Page No Medium Voltage Cables and Conductors .7 Levels of Over-voltages Experienced in a System . . 4.15 3.8 Means of Reducing Over-voltages . . . . . . . . .13 Minimum Creepage and Clearance Distances . . . . . . . .8 4. . . . .2 Special Considerations . . . . . . . . . . . . 3. . . . . . . . . . . . . . . . .13. . . . . . . . . .3 Integrity of Medium Voltage Electrical Power Supplies . . . 4. . . . . . . . . . . . . . . . . . . . . . .2 4. . . . . . . . . .12 Figure 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 3. . . .1 4. . . . . . . . . . . . . . . . . . . . . . 4.13. . . . . . . . . . .
. . . . D. 5. . . . . . . . . . . . . . . . D. . . . . . . . . E. . . .3 SAFETY RULES FOR WORK ON OR NEAR MEDIUM VOLTAGE EQUIPMENT CONTENTS . . . . . . . . . . . . . . Table F1 Figure F1 Figure F2 Figure F3 Figure F4 CORPORATE KNOWLEDGE AND EXPERIENCE . F. . . . . . .1 RELATED DOCUMENTS . . . . . . . . . . . . .9 Permit for Work . . . . . . . . . . . . . . . . . .1 SAFETY TERMINOLOGY . F. . . . . . . . . .1 Responsibilities for Medium Voltage Related Activities . . . . . F. . . . . . . . . .1 Statement of Technical Requirements Compliancy Matrix – Quality of Power Supplies . C. . . . . . . . . . . . . . . . . . . . . . . . INDEX 1
. . . . . . . . . . . A. . . . . . . . . . . . . . . . F. B. . . . . . . . . . . . . . . . . . B. . . . . . . . . . . . . .1 ABBREVIATIONS AND DEFINITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D. . . . . . . . . . . . . . . . . . . . . Table D1 Table D2 Table D3 ANNEX ANNEX E. . . .1 PROCUREMENT CHECK LIST . . . . .10
ALPHABETICAL INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . D. . . . . . . . . D. . F.1 STATEMENT OF TECHNICAL REQUIREMENTS COMPLIANCE MATRIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C. . . . . . . .8 Permit for Test . . . . . . . . . . . . . .7 Limitation of Access . . . . . . F. . . . . . . . . . . . . . . . . F. . . . .1 Statement of Technical Requirements Compliancy Matrix – User Equipment Constraints . . . .2 Medium Voltage Switching . . . . . A. . . . . . . . .2 Statement of Technical Requirement Compliancy Matrix – Miscellaneous Topics . . . .INT DEF STAN 02–607 / ISSUE 1 (NES 607)
Page No SECTION ANNEX ANNEX ANNEX ANNEX 5. .
there are four basic schemes where . NES 532. and to reduce conductor sizes and fault levels.
1. MV distribution systems. General
a. required vessel speed and. vessel profile.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
b. see also Annex A. For all but small and/or slow vessels. The current rating requirement of any generator exceeds 4 kA (1. DEF STAN 61-5 Part 4.
1. approach the following limits: (1) The prospective fault current exceeds 70 kA root mean saquare (rms) sustained at any point in the system (53. (2) As vessels increase in size and/or electrical loading. which in this NES will be systems with an ac voltage between 1 kV and 15 kV should be considered if LV parameters are likley to . independent sets of generators are required for the propulsion system and the ship's services system. Any system where LV parameters approach or meet the conditions of Clause 1.
Full Electric Propulsion: (1) (2) (3)
1. Type 23 uses LV for its low power electric cruise propulsion system.2
Electrical System Schemes which may Require Medium Voltage
a. IEEE Std 399. The capacity of individual generating sets exceeds 2.1c should adopt MV In practice. IEEE Std 141.5 MW (Lloyd's Rules). ultimately. In a vessel with a FEP system. NES 501. MV systems may be required for future vessels which adopt an electric cruise capability.
c. MV distribution systems or MV sub distribution systems may become necessary.IEE Regulations). However. HM Surface Ships and Submarines have used LV generation and distribution systems with a split generation operating policy. MV will be necessary in a high power electrical system to achieve acceptable voltage drops. Full Electric Propulsion (FEP) uses electric propulsion motors to propel the vessel at all speeds between standstill and full speed. IEE Regulations.4 MW at 440 V . The system fault levels under normal operating conditions exceed 50 MVA (Lloyd's Rules). MV will be required for the propulsion system. IEC 60-2. IEEE Std 242. Increasing electrical ships services loads and the operational advantages of electrical propulsion systems in HM Surface Ships and Submarines will require vessels with both Low Voltage (LV) and Medium Voltage (MV) electrical distribution systems. propulsion power requirement.
PERFORMANCE SPECIFICATION Related Documents: Lloyd’s Rules. these conditions may be met. This will depend on ship size.IEE Regulations).
Electric Cruise Propulsion Systems: (1)
d. Ships Services Systems: (1) Traditionally.3 MVA at 440 V . IEEE Std 519. A brief explanation is given for each. and where parallel generation operating policies are adopted.1
The degree of supply degradation beyond this point is the responsibility of the user equipment designer. MV will be required for the propulsion system. These converters may be power electronic converters. There are no prescribed power quality factor limits for the MV systems of HM Surface Ships and Submarines and consequently. Lloyd's Rules. For all but small and/or slow vessels.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
e. and that LV system fault currents do not exceed the conditions of Clause 1. Capital cost of equipment.3
1. Reliability of equipment under envisaged operating conditions. This point may be called the Point of Common Coupling (PCC). System configuration and operational requirements.2
. usually the user input terminals. and IEE Regulations give additional guidance on power supply quality issues. They also help to identify factors that contribute to power quality. The intent of this Section is to provide guidance on power quality issues for a MV power supply system. its characteristics and how the system operates.
d. filters. Early in the design process the supply. To specify the quality of power supply requirements for a system. protection devices.3.
1.1c . This may also be defined as the point beyond which the arrangement and cabling do not belong to the designers responsible for the electrical main supply and distribution system. The propulsion and ship's services systems are joined using converters. The attributes describe its arrangement. distribution panels. Integrated Full Electric Propulsion: (1) Integrated Full Electric Propulsion (IFEP) extends the FEP concept such that the power for the propulsion system and the ship's services system is derived from a common set of generators. rotary converters or some combination of these.
NES 532. circuit breakers. Indirect effects such as Electromagnetic Compatibility (EMC) and the effect on signatures.
e. loads and instrumentation.
1. Electrical systems consist of essentially nine main items: sources. Technical capability of equipment. The agreed point may or may not be the point of common coupling. distribution lines. Care is required in the design of the propulsion system to ship's services system interface to ensure that the desired ship's services power quality is maintained. The tolerances applied to a particular electrical supply appertain to a specific point in the supply system. c. such limits must be considered at the initial stage of the system design and account for such aspects as: (1) (2) (3) (4) (5) b. Most of these items contribute to the quality of the power supply and all of the items are susceptible to its quality to some degree. converters. distribution and user authorities/designer are to agree the precise point at which the tolerances apply.1
Quality of Medium Voltage Power Supplies
General a. DME/ME242 may arbitrate if necessary. transformers. it is first necessary to define some of its attributes.
An active rectifier. conductor resistance goes up from its dc value. Both factors cause higher voltage drops and hence extra power losses. However. Compliance may also be required in a power electronic coupling system.1
Rectifiers a. LV systems comply with DEF STAN 61 5 Part 4. which can result in large harmonic currents. such as iron magnetic saturation. which controls the current waveform using high speed switching devices. and reduces still further with a fully controlled rectifier bridge.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
1. In idealised cases.4
Compliance with DEF STAN 61-5
a. Most electronic equipment incorporates one or more high speed switching devices. MV compliance is required when MV/LV systems are coupled in the following ways: (1) (2) (3) Mechanical coupling (e. this benefit comes at increased complexity. Harmonic levels can also amplify owing to the excitation of parallel or series resonance. generators.
b. This equipment includes motors. Events external to the power system (e. lightning strikes) can also affect power quality. Conversely. a series resonance circuit has a low impedance and the current flowing into the impedance is high. generators and transformers are usually small and result from mechanical constraints within the item.
c. transformers and equipment containing electronic components.
d. Transformer coupling. the rectifiers would produce only characteristic odd harmonics.
1. The level of distortion introduced by electronic equipment can vary significantly depending upon the complexity of the input stage. tandem generators driven by a prime mover. can reduce the harmonic component of the current to minimal levels.
b. However. 1. winding slot spacings. A parallel resonance circuit has a high impedance to a harmonic current.5
Contributors to Waveform Quality
a.5. There is no requirement for MV systems to similarly comply. or a rotary voltage/frequency converter). The action of these devices can impress high frequency distortion onto the system fundamental waveform.
c. stator and rotor eccentricities. These harmonic currents cause voltage drops that distort the supply voltage waveform at the point of common coupling. Harmonic current flows reduce the efficiencies in generating and delivering electricity. which must be accounted for in the early MV systems design process. All non linear equipment connected to the system will affect waveform quality.g. The worst effects on ac systems are caused by diode bridge rectifiers. This occurs because of two reasons: Harmonics increase the rms value of the current. The distortion reduces when the rectifier is a half controlled bridge circuit.3
. which defines power quality factors.
1. size and cost. The waveform distortions from motors. in practice they also produce some amounts of non characteristic even harmonics. This harmonic current flowing into the impedance is low and the harmonic voltage across it is high.g.
and eventually puncture.4
. Surges in voltage. it can increase copper and iron losses and decrease efficiency.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
1. a voltage imbalance of 3. Voltage and current balances affect the temperature rises in electrical machines. Any equipment that transiently draws a high current can cause a voltage or frequency sag. usually that of a transformer. A prolonged sag in voltage can cause excess current in equipment.
1. even from single spikes. relays and insulation are also at risk. A reactance on the input to a rectifier. Spikes can be one of the most damaging forms of distortion. The effects depend upon the characteristics of the distortions and upon the nature of equipment. to another.3
Harmonics a. It is more likley to result in operational difficulties than equipment damage. though the damage may not be apparent straight away.6. and energisation of power transformers and capacitors.
1. Notching occurs when two power supply lines short together as current transfers. A surge can put the magnetic circuits of motors and transformers into saturation. All the constituents of a power system are susceptible to harmonics.3
Load Balance a.1
Spikes. it can also cause motors to stall and lead to tripping of protection relays.
b. Motors are usually more robust to single spikes. or both.
1. Any equipment that rapidly stops drawing a large current can cause a voltage or frequency surge.6. Filters. which is another form of waveform distortion. but recurrent spikes can stress. The division of load amongst the three phases of an ac power system also contributes to power quality. Surges and Sags a.2
Voltage and Current Line–to–Line Imbalances a. which are inevitable. or commutates.
1. Bridge rectifiers also cause notching in the ac supply waveform. If the condition persists. Unbalanced impedance draws unbalanced current flows.
1. depending on their size.2
Starting and Inrush Currents a. Electronic equipment is particularly prone to immediate and destructive failure.6
Susceptibility to Waveform Quality
a. NES 532 and IEEE Std 519 contain further information on harmonic analysis. either voltage or current. from one diode. which create imbalances in the line voltages at the point of common coupling.5. can cut deep notches into the ac voltage.5. particularly in dc systems.6. For example. or thyristor. which would probably be intolerable. winding insulation. duration and frequency may also damage equipment.5% can cause a 25% increase in temperature rise in a motor. A spike can inject considerable energy at high voltage into several items of equipment simultaneously. The distortions in a waveform have different effects on equipment. The same events may also produce voltage spikes. and some standards recommend a minimum amount. Such commutation overlaps. The usual events are direct on line starts of induction motors. limits the notch depth at the point of common coupling.
Some of the torques act in the same sense as the fundamental component of torque. Transformers suffer higher hysteresis and eddy current losses from voltage harmonics. which can mask its true state of charge and may shorten its life. Harmonics in a dc voltage can cause difficulties for equipment connected to a dc system. an alternating voltage or current injected into a battery can cause increased gassing. and thereby increase the harmonic components in the magnetising current. These harmonics increase copper and iron losses. noise and vibration. Extra losses occur in the windings and laminations of both the stator and rotor.
d. which hinders smooth starting. The root mean square (rms) value of the total current is higher and the conductor resistance increased owing to skin and proximity effects. particularly if it occurs near to a resonant frequency in the motor load system. but the increase is mostly in the rotor. The voltage ripple may pass through to the output of an inverter drive. which cause them to overheat and fail.
1. Electric motors are susceptible to a voltage waveform that contains harmonics. Harmonic components in the current waveforms lead to greater copper losses.
c. The high dv/dt of the notches can also create other problems: ringing between capacitance and inductance. If this occurs. f. in capacitors and to earth. while others act in the opposite sense. which also impose greater stress on the winding insulation. These notches can potentially cause false zeros in the ac waveform. It may also cause a cogging effect.6. Harmonic torques arise because each harmonic in the stator current produces a magnetic field that interacts with currents flowing in the rotor.
g. Additionally. This pulsation can cause vibration problems. and a crawling effect or a stall.
h. The actual notch depths depend upon the impedance between the rectifier and the point of common coupling. create harmonic torques and increase acoustic noise. It may also lead to shallow cycling of the battery.5
. a dc component in the secondary current can saturate the magnetic circuit. Harmonic voltages also supply an additional stress to insulation. Harmonic currents drawn from a generator have effects that are similar to those that occur in motors: i.5
Voltage Ripple a.
e. increased losses. Voltage harmonics cause additional power losses in the dielectric material of capacitors. The losses are proportional to the harmonic frequencies and the squares of the harmonic voltages.4
Notches a.
1. Though the effect on the mean torque is small. leakage current. which can shorten its life.6. The extra losses reduce a motor's efficiency and can shorten the life of its insulation.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
b. and raise the battery temperature.
1. there can be a significant torque pulsation. Harmonics can also excite a resonance between capacitors and inductance in a system. The notches that rectifiers cut in the ac voltage waveform can affect other equipment that uses the waveform as a timing signal. Harmonic current flows increase I2R losses in cables. the capacitors may experience high voltage or high current.e. which becomes a source of interference. Similar effects can occur in filter chokes.
This will impose performance requirements for some fault conditions. For multi megawatt equipment the size.then the constraints applied in those installations can be used as an initial guide. batteries. It is possible that the constraints placed upon such equipment will be more relaxed than for equipment supplied from a lower voltage ship services busbar. existing systems .6
Modulation (Flicker) a.
1. The simulation model must then be refined as the system design progresses. It is necessary to determine the requirements for equipment supplied from the MV system.7.
b. Generator governors and voltage regulators also respond to modulation effects and care is necessary to ensure that control systems cannot become unstable.
c. The effect gets its name from the visible flickering of lighting. It also occurs with a cyclic variation of frequency.
b.6. Similarly.
d.such as offshore oil and gas platforms perhaps . Equipment may contain energy storage elements: inductors. The requirements for equipment supplied from 440 V ac and 250 V dc power systems are well known and documented in NES 501.for example.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
1. This action may amplify generators' current and machinery vibrations if the modulating frequency is close to a resonant frequency.7
Users’ Constraints
a. Initial estimates for the constraints can be obtained in two ways. There will be some physical aspects of the equipment that will be defined for power system quality reasons. Firstly.6
. computer simulations can be used to predict/confirm the effects of disturbances to the system. The constraints may also include equipment hardware design requirements in addition to equipment performance parameters. Constraints must be placed upon users to control the levels of disturbance injected into the electrical system. if the system voltage and size is comparable with other.
1. These may include connection and cable glanding arrangements. it is possible to determine which parts of the distribution system will require strengthening to tolerate a more disruptive (and cheaper) piece of equipment. capacitors. Power systems quality must remain within the prescribed limits during system or equipment faults. This latter approach is potentially very useful because the effects upon the system of relaxing users' contraints can be freely explored . etc. equipment that contains inbuilt fault protection facilities must co ordinate with the rest of the electrical system. Cyclic changes in frequency will also cause motors to accelerate and decelerate. cost and weight penalties of such constraints must be balanced against the likely risks. To maintain system quality it may be necessary to limit either the amount of energy that can be discharged into the system or the rate at which it can be discharged. flywheels.1
Equipment Hardware Constraints a. This may be applied for a limited range of conditions. Periodic changes of load can lead to voltage modulation or flicker. cable entry routes and equipment internal layout. Secondly. All equipment connected to the electrical power system must operate within certain limits as defined in the power system design and any relevant standards.
Equipment Performance Constraints a. Both the duty cycle and the period of a pulsed load affects which disturbance frequencies are prevalent. To prevent this. this will result in unbalanced voltages at the PCC and throughout the system. This depresses the voltage at the PCC for the period of commutation causing notching of the system voltage waveform. Duty cycle and period of pulsed loads. the electromagnetic emissions of itself or other equipment.1 – Users’ Constraints
b. The periodic nature of the transients may excite resonances within the system which amplify the voltage disturbance. Permitted out of balance load on a 3 Phase supply. Commutation notch depth and duration restrictions: Notch depth. the level of both conducted and radiated emissions must be limited. Large current flows can cause voltage and frequency transients on the electrical system while even small inrush currents can cause earth leakage. they may occur at frequencies at which the system response is poor and this could result in undesirable system frequency oscillations. Earth leakage currents.
e.7. To prevent damage or danger to personnel. Equipment short circuit fault current rating.
Table 1. The size of the notch must therefore be limited to the control of harmonics introduced into the system voltage waveform.
1. Pulsed loads apply repetitive transients to the system. or be affected by. Large circulating currents can flow which increase the internal heating of transformers. Notch area. Conversely. Most equipment draws a surge of current from the supply when it is switched on. Table 1. generators and motors. THD (voltage). current protection devices to operate.1 lists users' constraints. Equipment operation can affect. During short circuits faults a current will flow that is many times greater than the normal rated current of an item of equipment. Harmonic ac current/ripple current maximum amplitudes for rectifier loads: Total Harmonic Distortion (THD) (current). This can be significant for loads containing appreciable amounts of inductance or capacitance. Conducted and radiated EMC limits. or residual.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
1. An out of balance 3 Phase load will draw unbalanced currents from the supply. User Equipment Constraint Switch ON/Start up current transient limitation. Due to the line reactances and resistances.7
c. all equipment must be capable of withstanding the potential short circuit current that may flow through it until a protection device operates to disconnect the fault.
f. The distorted waveform contains harmonics.
g. When current commutates from one device to another in a rectifier the input connections to the equipment are effectively short circuited.
of an MV system can be defined by placing limits on the permitted values of a number of quality factors. Line voltage unbalance tolerance for 3 Phase systems. Voltage sag: Voltage surge: depth recovery time depth recovery time depth recovery time depth recovery time
Nominal frequency and steady state tolerance.
Average of three line to line voltages for 3 Phase systems. Maximum deviation of any one line to line voltage including average of three line to line and unbalance tolerances. ac Power Quality Factors Fixed voltage system: Variable voltage system: Nominal voltage System voltage range. dc offset.8
. The operating envelope.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
Quality of Power Supply Limits
a. Table 1. Waveform harmonic content: Individual Total Harmonic Distortion (THD) Deviation factor peak value waveshape energy content
Table 1. or quality.2 – ac System Power Quality Factors
1. Frequency sag: Frequency surge: Frequency modulation. Voltage modulation.2 lists the parameters that must be determined.
This Section provides guidance on the safe working practices applicable to electrical distribution systems on board HM Surface Ships and Submarines above 1 kV ac and not exceeding 15 kV The guidance provided within this . oil or other flammable substances.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
2. These are only to be moved or operated on the instructions of an AP who is to be responsible for them. ensure that the necessary safety precautions have been taken and.1
2. electrical distribution systems and associated plant. . Health and Safety at Work Act 1974. BS 2929. or until or unless instructed to do so by the person in charge of the work who is authorised by the Authorised Person in Control (APC). barriers or other access limiting devices. safety barriers. No person is to smoke or use an exposed flame in any unventilated compartment or other similar enclosure until it has been declared safe to do so by the AP in charge of the work. Safety
Scope and Allocation a. It is the responsibility of all persons working on. No person may enter a MV compartment. open a link box or distribution panel. Smoking is prohibited at all times in the vicinity of any open tank which contains. Should any person consider that the instructions given cannot be carried out safely. IEE Regulations. or in the vicinity of.
c.1. or other safety devices. if he thinks it necessary. danger and caution notices. No person is to interfere with earth connections. he is to ensure that a person is stationed outside the compartment to maintain constant contact with those persons inside. roping. No person is to enter a confined space that has previously contained oil or other flammable or toxic substance until instructed to do so by an AP The AP will . Section. In the case of conflict between this guidance document and statutory/mandatory regulations. when applied.
f. by suitable ventilation or other means. no work may be carried out outside the working zone defined by danger and caution notices.1
. to prevent fire or explosion. equipment and apparatus.
b. or has contained. exceeded. These rules are to be used in conjunction with all current MOD(N) safety documentation.
e. disturb a cable or interfere with any other item of electrical equipment unless he holds a written instruction permitting him to carry out these duties.
d. In addition.
2. Precautions are to be taken. This Section should be used as the basis for ship specific/class specific MV safety rules as required. touch the insulation covering or supporting any conductor. to report to their immediate superior any malfunction or situation which could pose a danger in terms of risk to health or bodily injury. BS 5378. see also Annex A. Electricity at Work Regulations. No person is to commence work until he fully understands the instructions he has received from an AP In no circumstances shall those instructions be .
NATIONAL/INTERNATIONAL REGULATIONS Related Documents: Lloyd’s Rules. he is to refer the matter to a higher authority for a decision before proceeding.1
2. the statutory/mandatory regulations shall take precedence. should cover the relevant mandatory/statutory requirements.1.
General Safety Precautions a. or omissions from this guidance document. locks.
It is important that no person enters any space in which there has been a fire until permitted and instructed to do so by the APC. tested. Any variations must comply with the law and ensure that safety requirements are satisfied. scaffold pole.
Whilst not statutory.1. operated and disposed without risk to health at any time.3
Responsibilities for Safety a. The following Acts relate to MV safety rules: (1) (2) b. cleaned and maintained. employees. The use of portable fire extinguishers containing water or foam is totally prohibited. In exceptional or special circumstances.
2. Electricity at Work Regulations. Any person instructed to carry out work in accordance with these rules are to ensure that they fully understand the instructions given and shall seek clarification when necessary. The variations are to be issued in writing and distributed to all controlled copy holders of these rules.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
h.1. crane. (1) (2) 2. by any person carrying out instructions covered by these rules. ladder. installed. manufactured.Regulations for the Electrical and Electronic Equipment of Ships with Recommendations for their Implementation. the following are relevant documents:
Variation of the Electrical Safety Rules a. writing to do so by the Authorising Engineer (AE).5 Health and Safety at Work Act.2
2. plank or other long object into a compartment or enclosure until instructed by the APC. move or use lifting equipment.
2. to be reported by him to the person issuing the instructions. they will be safe and without risks to health at all times when they are being set. designers and manufacturers. All objections will be investigated and if necessary referred to a higher authority for a decision. the Senior AP where authorised in . No person is to work in any compartment or other enclosure fitted with automatic fire fighting equipment until the system has been inhibited and he is instructed to do so by the APC.Rules and Regulations on the Classification of Ships. Lloyd's Register of Shipping: . Effective procedures will be instituted to allow objections.4
Statutory Safety Requirements a.2.2
. maintained.1
Description a.1. used for their intended purpose. is to have the authority to vary the MV safety rules.6
Objections a.
i. all equipment is to be designed. care must be taken to maintain appropriate safe handling distances between the extinguisher and any live apparatus or conductors. Whilst using portable fire extinguishers. All MV systems and equipment must be designed and manufactured such that as far as is reasonably practicable. IEE Regulations: . mobile work platform. The Health and Safety at Work Act 1974 places a general duty for safety on employers.
2. In essence this Act requires that as far as is reasonably practicable. No person is to take.
(1) have undergone a period of local training to become fully acquainted with the MV safety rules and any authorised variations.
e. Annex F provides guidance on the format and contents of such rules and should be used as the basis for any locally derived and authorised rules. by the AE. e. depending on the equipment fitted in each case. Operating handles and all selector switches must be lockable. Where practicable. A copy of the authorised rules is to be issued to everyone who is called upon to work on. annually or when a change in Statutory Regulations takes place.4.3
. or operate MV distribution equipment. see Annex E. All MV cables and cable routes are to be arranged to avoid passing through any compartments which have unrestricted access.3
Review a. equipment and installation with which they are concerned. Safety Terminology is detailed in Annex F. d. Construction is to be such that the trip circuit is to be disabled prior to closing into the earth position.2. All busbars and circuit shutters are to have provision to have safety padlocks fitted. To ensure that all statutory regulations are met. Each person must sign a receipt for his copy of the rules and is required to be conversant with the content.
c.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
c. operation and maintenance of MV distribution systems are to be undertaken strictly in accordance with a set of written electrical safety rules. d.
2. Where this is unavoidable. all work connected with the control.3
a. consideration should be given to providing a mechanical barrier to any such cable. have undergone a period of training on the particular system. 2.4
Authorised Person a. An Authorised Person must. For details of Safety Rules. all MV cables are to be clearly marked and suitable warning notices posted.2
Safety Rules a. These rules are to be reviewed. Circuit breakers must be of the withdrawable type and are to be provided with an integral means to earth isolated circuits so that they are discharged and made safe to touch. Safety rules for individual vessels shall be produced on an individual/class basis. applicable Statutory Regulations and Naval requirements.
2. A Competent Person must.5.2
Danger Notice a. Additionally.
2.MEN WORKING' in a black on an orange/yellow background (as defined in BS 2929). equipment and installation with which they are concerned. applicable statutory regulations and Naval requirements. or to test the equipment with which they are concerned. (1) have undergone a period of local training sufficient to provide an adequate knowledge of the MV safety rules and any authorised variations. (1) a period of training and supervision sufficient to safely control the operation of the MV distribution system safely. Training requirements are as for an AP with the addition of. have satisfactorily completed first aid training for the treatment of electric shock.3
Competent Person a. A notice in approved form attached to apparatus or its control equipment when live. applicable Statutory Regulations and Naval requirements. Must have undergone a period of training to become intimately acquainted with the MV safety rules. This training is to be sufficient to allow the interpretation of the safety rules and other statutory requirements and also allow the formulation of local variations.1
Medium Voltage Warning Signs
Caution Notice a.5
2. First aid training will be carried out at regular intervals not exceeding three years.4.
2. All levels of staff will also be subject to periodic refresher training at defined intervals. conveying a warning against interference with the apparatus.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
(3) have undertaken a course of training to be technically competent to safely operate and make safe to work. The notice carries the words `CAUTION .5. have technical training sufficient to avoid any danger presented by the work to be undertaken. have satisfactorily completed first aid training for the treatment of electric shock. have undergone a period of training on the particular system.4. calling attention to the danger of approaching or interfering with such
(4) 2.4
2. to work on. APC is to carry out periodic touch drills to maintain an acceptable level of competency.2
Authorised Person in Control a. A notice of approved form attached to apparatus or its control equipment.
(2) (3) (4) 2.4
Authorising Engineer a.
Compartment location.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
apparatus.5.4 First Aid a. `Danger of Death' sign.3 Compartment Notices a. `Warning High Voltage Equipment'.5. This is to be fixed permanently in position. Compartment key location. 2.
2. The door to any MV compartment should carry the following signs and information: (1) (2) (3) (4) (5) (6) 2. `No Smoking/Naked Flames'.5
. Emergency telephone number. The notice carries the words `DANGER . Within every MV compartment should be: (1) (2) A substantial first aid kit identified by a safety sign to BS 5378. Posters showing resuscitation techniques following electric shock.LIVE EQUIPMENT' in red on a white background (as defined in BS 2929).
.2. To assist in the determination of generator capacity.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
3. BR 8473. IEC 787:1983.1. IEC 331. diversity and utilisation. c.1a . The designer will then need to determine whether the transient capability needs to be local to the pulsed load. BS 4999 Parts 143 and 144. The continuous rating of any pulsed loads should be entered in Table 3.
MILITARY STANDARDS/REQUIREMENTS Related Documents: Lloyd’s Rules. or global to the MV system. DEF STAN 61-12 (Part 31). BS 6883. The loads of the LV Systems which interface with the MV System being considered should be calculated using the methods detailed NES 532. BR 8471. Here it is assumed that the pulsed load will be fitted with its own pulse generator/power supply which will present a continuous load to the vessel's power distribution system. zero knots in harbour may have a significantly different load from zero knots in an action situation.
f. NES 501. 3. BR 3021 Volume 1 and 2. c. BS EN 60644. For example. BS 6360. The Load Chart method of estimating system loads detailed in NES 532 is applicable to MV systems. d. IEE Regulations. It requires that propulsion loads and ship's services loads are calculated for a range of vessel speeds. where the vessel speeds considered should reflect the platform and its required operating profile. BS 2692 Part 2. e. BR 8470. sonar and large direct on line started electric motors. NES 532.
3. BS EN 60298. b. NES 502. Clauses a. a. BS EN 60282-1. These pulsed loads may be periodic or aperiodic. see also Annex A.1
3. It may be useful to consider various vessel operating activities at some of the vessel speeds. 18 knots in tropical conditions may present a different load to 18 knots in arctic conditions. If pulsed loads require pulses to be supplied from the main power system the data should be entered in Table 3. BR 8472. Typical growth margins for LV systems will apply to these MV systems. NES 530. various factors e. will require to be determined for the MV system loads. However. BS EN 60694(1997). Table 3. and may include pulsed weapons. drills and action conditions to be assessed. the determination of generator operating schedules and planning of the layout of the electrical supply systems for new or modified designs.
d. Medium Voltage Electrical Power Requirements
Medium Voltage Systems which do not Supply Electric Propuslion Systems a.
c. the total load is to be assessed at various vessel speeds and the assessment calculation is to be presented on a load chart. These weather conditions may then require further sub divisions to enable peace time cruising. e and f should replace NES 532 Clause 3. Minimum load situations on the LV system may demand a LV generator to achieve acceptable generator loading.1. One page of the table will be required for each pulsed load. BS EN 60071.1
3.1.g.1.1 shows a suggested load chart format. This table will provide an indication of the transient capability required from the power system.2
Medium Voltage Systems which Feed Electric Propulsion Systems This clause refers out to NES 532 with the following exceptions. Similarly.
g. The daily load variation of a MV propulsion system will differ from that of a typical ship service but will be similar to a conventional propulsion system in a similar role.1 and 3. Load requirement should include motor. 2.
Electrical Power Requirement Ships Services2.1) Min Max Likely
Vessel Vessel Propn 1. Load requirement should include transformer and converter inefficiencies. 3. converter. The units for the load are MW if dc.2 Propn 1.2) Min Max Likely
NOTE: 1.3 Min Max Likely Sub total 2 (for Table 3. or MVA if ac.2 Propn 1. transformer and filter inefficiencies.2
Table 3.2 Speed Operating Drive 1 Drive 2 Drive n (knots) Activity MW MW MW 0 3 8 15 19 23 25 27 30 31 Load State Vessel Vessel Speed Operating (knots) Activity 0 3 8 15 19 23 25 27 30 31 Pulsed Weapons 2 (Continuous Rating) Min Max Likely
Electrical Power Requirement Miscellaneous MV Equipment 2 Min Max Likely Total2 (for Tables 3.1 – Load Chart for a Medium Voltage Electrical System Which Feeds Propulsion
Load requirement should include pulsed equipment inefficiencies. isolating only those parts of the system affected by the fault. The basic rule is whenever possible.2 Pulse Cycle Duration 3 Duration 3 0 3 8 15 19 23 25 27 30 31
Operating Period3
NOTE: 1.2. (1) Discrimination by time alone may mean that more severe fault currents are not cleared in the shortest possible operating time. to use relays with the same operating characteristics in series with each other.2
Current Protection a.1
General a. isolation must be selective.
b. The protection relay settings are determined to give the shortest operating times at maximum fault levels and then checked to see if operation will be satisfactory at the minimum fault current expected. over current. 2. Various protection devices are available for protecting generators. Among the methods to achieve correct relay co ordination are those using either time.3
. To maintain the high integrity of supply required for HM Surface Ships and Submarines.2 – Load Chart for Pulsed Loads on a Medium Voltage Electrical System 3. Correct current relay protection requires knowledge of the fault current that can flow in each part of the power system network.2.
Table 3. feeders and power consuming equipment having rated voltages greater than 1 kV The . The time unit should be suitable for the application. purpose of the devices is to detect and rapidly isolate all system faults.2
3. The common aim of these methods is to provide correct discrimination and thereby isolate only the faulty section of the network. or a combination of both.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
Electrical Power Requirement For Pulsed Loads
Vessel Vessel Pulsed Load Name: Speed Operating (knots) Activity Power1. The units for the load is MW if dc or MVA if ac.
With this relay.
When protecting the motor supply cable with fuse links. However. When protecting transformer supply cables.
3.9). The limitations of time or over current co ordination can be overcome by a relay using both methods.1.
e. A number of relay variations use both time and over current.
3.11. High frequency of starting will not allow the fuses to cool down between starts. an example being the Inverse Time Over current (ITO) relay. Under voltage is covered in Clause 1. Defective operation of the AVR. If the fault level at the fault is in excess of the rupturing capacity of the device.
Means of reducing over voltage are discussed in Clause 4. Current Limiting Reactors are reactances employed to limit short circuit currents.
f. c.1 shows an example of Co ordination of ITO Relays. damage to the installation and the protective device can result before the current is completely interrupted. they may be caused under the following conditions: (a) (b) b. (1) Over voltages should not occur on a machine fitted with an AVR. Power Frequency Over voltages.4
.6. Therefore. In such cases the protective device must be backed up by another breaker or by fuses capable of interrupting the fault. They are used to reduce short circuit currents to a value which is `acceptable' with regards to the short circuit withstand capability of equipment or the breaking capacity of circuit breakers.3
a. the main criteria for the selection of fuse links is covered in IEC 787:1983. NES 532 contains fuse rupture characteristics up to 16 kA. the time of operation is inversely proportional to the fault current level and the actual characteristic is a function of both time and current settings. Effects of Fault Currents (1) To ensure over current protection devices can safely deal with fault currents. attention must be paid to the motor starting currents and starting time. discrimination by current can only be applied where there is an appreciable impedance between the two circuit breakers concerned. Operation under manual control. knowledge of any prospective fault current is necessary.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
(2) Discrimination by current relies on the fact that the fault current varies with the position of the fault because of the difference in impedance values between the source and the fault (see Clause 4.
2). it may be necessary to make the response of the relay directional by the introduction of directional control.4 Parallel Feeders
a. D Voltage controlled inverse time over current relay
Figure 3. comprising a combination of inverse time over current and high set instantaneous over current elements. C Independent definite minimum time over current relay.1 10 100 1000 10000
Fault Current to Common kV Base MVA Generator
Relay Examples: A Thermal relay combining Motor Thermal Protection Unit (MTPU) with high set instantaneous over current elements for short circuit protection.5
.1 – Co-ordination of Inverse Time Over-current Relays 3.
3. B Composite triple pole relay. When fault current can flow in both directions through the relay location (see Figure 3.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
3. Use of non directional relays on parallel feeders means that.2
Indirect Contact a.
Non-Directional NOTE
The directional elements look into the protected line and their time and over current settings are set lower than the non directional relays.5. Therefore. directional relays must be applied at the receiving end which are then graded with non directional relays at the source end. The use of dead line indicators prior to touching any exposed conductor is recommended to prevent electric shock. owing to creepage paths. they can come in contact with live parts as a result of a fault.
3. The shorter the duration of the fault current.
c. High impedance neutral earthing.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
. arcs or direct contact. The neutral earthing policies considered appropriate to MV systems in HM Surface Ships and Submarines are: (1) (2) Unearthed neutral.5. all non live parts of equipment must be earthed if. In the event of a system fault to earth.6
Earthing Policy for Medium Voltage Systems in HM Surface Ships and Submarines
a. any fault on one feeder may isolate both lines and completely disconnect the power supply.
Figure 3. When protective earthing is used.5
3. the earth path carries at least part of the short circuit current. the higher is the permitted maximum value of touch voltages occurring in the installation.1
Protection Against Contact Above 1 kV
Direct Contact a. regardless of relay settings.
3. to ensure correct discrimination operation during fault conditions. In MV installations with low resistance neutral earthing the maximum touch voltages allowed depends on the duration of the fault current.2 – Parallel Feeders 3.
(1) Electric Shock .7
Continuity of Supply (a)
3.7.Recommendations for the Electrical and Electronic Equipment of Mobile and Fixed Offshore Installations. therefore. Satisfactory installations of all types and voltages can be engineered. certain factors apply equally. The following factors are significant when selecting a method of neutral earthing: (1) Earth Faults (a) Earth faults are the most common fault.
Over voltage (a)
System Voltage (a)
3. for the argument to be valid. A solid earth fault on a high impedance or unearthed neutral system will increase the phase to earth voltage stress on the two healthy phases for the duration of the fault. However.
c. are produced by switching surges which are independent of the treatment of the neutral.7
.7. the majority occur in miscellaneous electrical equipment. Appendix C. These methods are not.Phase to Earth (a) Human tolerance to shock currents is so low that any method of earthing the neutral has the possibility of allowing lethal currents to flow. and are summarised below. the earth fault must have caused the loss of an essential supply.2
Factors Not Significant a.
3.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
b. In 3 Phase circuits. the neutral point is treated and so can be disregarded when selecting between methods. Continuity of supply following a single earth fault is an important argument in favour of the unearthed and high impedance methods but.1
Considerations in Selecting Earthing Method
Preferred Method a. These earthing methods and their associated advantages and disadvantages are discussed in detail in lEE Regulations . The preferred method for treating the generator earth is to provide a high impedance connection to the ship's hull.
3. be used in MV systems for HM Surface Ships and Submarines. The large fault currents and large circulating triplen harmonic currents associated with solid earth and low impedance neutral earthing present an unacceptable risk of fire. single phase to earth faults are likely to escalate into phase to phase faults unless measures are taken to reduce this likelihood. The largest and therefore the most significant over voltages on marine systems.3
Significant Factors a.7. System voltage itself is not a determining factor in selecting a neutral earthing method. Although important in their own right.
although it is normal to provide a device warning of an earth fault on the system. fault location is either expensive (special fault locating equipment) or time consuming (fault located by successive isolation of suspect circuits).
Fault Location (a)
Fire Risk (a)
3. Tolerance of comparatively high earth strap bonding impedances before an indirect shock risk arises. The risk is dependent on the magnitude and duration of the fault current hence. typical natural frequencies are of several kHz but the system losses are such that these frequencies are normally over damped hence the associated over voltages do not occur. Fault location is a manual task. The advantages offered by the unearthed system are: (1) (2) Continued operation with single earth fault present.4
Flash Hazard a. Earth faults must be located quickly to prevent a phase to phase fault arising from a second earth fault. The risk dependencies are the same as those for fire. Very low fire and earth fault flash hazards during a single earth fault. A flash hazard arises when a fault occurs close to people.8
. In marine systems. The system neutral is isolated from earth (i. This can occur on unearthed neutral systems if the arc associated with an earth fault extinguishes and restrikes producing over voltages at the natural frequency of the system. The significant system over voltage that is influenced by the method of system neutral earthing is the `intermittent earth fault'.7.e. In high impedance systems. Minimal earth fault protection cost since low fault currents do not normally constitute a fire risk.8
Unearthed Neutral Systems
a. Fires can arise from burning at the point of fault or from ignition of flammable materials or gases by a fault arc.
(3) b. the hull or earth system in non metal hulled vessels) although there will be an unavoidable connection via the phase to hull capacitance of the MV system. is greater in low impedance earth systems.
The disadvantages of the unearthed neutral are: (1)
(3) Switchgear Rating (a) (4) The most onerous duty for marine system switchgear will normally be a phase to phase or 3 Phase symmetrical fault. This fault finding procedure can be more disruptive to the system than automatic fault isolation systems. since it is usually uneconomical to install sufficiently sensitive detection devices.
c. Continued operation with an earth fault is not possible. Earth fault relays can be provided economically to locate and isolate earth faults automatically. This method involves the connection of the system neutral to earth via an impedance. The phase to earth over voltage caused by an earth fault is reduced compared to an isolated neutral earth system. The value of the impedance is determined by the desired level of earth fault current and phase to earth over voltage. Estimate the system capacitance fault current at the design stage and then measure it to ensure the installation matches the design figure and any difference does not represent an unacceptable fire hazard.9
High Impedance Neutral Earthing
a. A warning notice should be installed adjacent to the earth fault indication in the event of an earth fault on the system. Earth fault protection equipment is an additional capital item and maintenance load. For example: (a) (b) Allow adequate cable spacing which may facilitate the use of fault locating equipment.
Considerations for Earthed Neutral Systems are: (1)
3. The neutral points of the MV generators are to be bonded to the ship's structure at a single point via individual resistors/impedances to limit the fault current. Assess the benefits offered by phase segregation barriers to reduce the likelihood of earth faults becoming phase faults. consider what actions can be taken to ease the fault location problem. and is the preferred method for high voltage systems on HM Surface Ships and Submarines. The risks associated with fire and earth fault flash are small. ensuring that a system is earthed at only one point requires considerable automatic switching. the advantages offered by the method are: (1) (2) (3) (4) b. Comparatively high earth strap bonding impedances can be tolerated before an indirect shock risk arises. Establish procedures for regular earth fault checks on the system and for their immediate location and repair. Considerations for the Unearthed Neutral System are: (1) At the design stage. The possibility exists of significant triplen harmonic current flow if generators operating in parallel are earthed at more than one point. Bonding between resistors are to be separate to that provided by the ship's hull to minimise possible interference with communications systems. Assuming the earth fault current is limited to a small value.
The disadvantages offered by the method are: (1) (2) (3) (4)
c. A failure of the earth fault protection equipment would create a fire risk due to fault current flow.
13. the requirements for equipment selection are similar to those given in NES 501 and NES 532. Circuits must be isolated and safely discharged before commencing work. It is vital to ensure that no conductive parts of equipment can accumulate dangerous voltages when undergoing maintenance tasks. and Limited Fire Hazard (LFH) and Zero Halogen (ZH) characteristics.
General a. The cables must have conductors to BS 6360 Class 5.13
3. Equipment for MV systems is to be designed. particularly with regard to legal requirements for such equipment. Cable sheath is to be coloured red to distinguish it from other cables. IEC 331. Equipment for MV systems is subject to further requirements. Cables used in systems above 3. Where an earthed system is divided into two or more sections. as far as practicable. The fault current shall be at least three times the value required to operate any earth fault protection devices.10
. for example. regardless of whether or not the cable is armoured.
b. Some circuits may require fire resisting cables to.10
Maintenance Earthing
a. Medium voltage cables are to be in accordance with BS 6883-1991 with the following exceptions and additions: (1) (2) Selection of a suitable cable for MV applications is to be in accordance with the requirements of NES 502. This is to ensure even voltage stress on the insulation and avoid touch potential problems at the cable surface. Effective means are to be provided for indicating defects in the insulation of the system. In general. This is to provide superior tear and oil resistance.1 are observed (safety by design). Refer to Lloyd's Rules for further MV earthing requirements. Provision must be made for temporary earth connections to be made to MV equipment conductors which may become charged through leakage from MV circuits.1
Further Earthing Requirements
a. means are to be provided for neutral earthing of each section.1
Medium Voltage Cables and Conductors
Cable Selection a. Braided copper wire screen is to be used on the cores.3 kV must be provided with a continuous metallic sheath.12.11 3.12
3. The STR will specify if and where fire resistant cable sheath is required.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
(3) Earthing resistors are to be selected such that the earth fault current is limited to a value not exceeding the full load current of the largest generator.
3. such that the safety requirements of Clause 2. The cable sheath is to comply with DEF STAN 61 12 Part 31. This is to provide additional flexibility to assist during installation and to improve shock resistance of equipment.
3. to avoid the requirement for MV bulkhead penetrations.2
HM Surface Ships a. local protection of cables may be needed in hazardous areas. It is not necessary to provide armoured cables or a galvanised steel wire braid throughout the MV distribution system. c.
3. MV cables must not be run through the Reactor Compartment of submarines.14.2
System Considerations a. b. MV cables must be provided with a cable support system. However. d. MV cables must be readily identifiable and must be segregated from LV cables. watertight glands or multi transit assemblies.1
Submarines a. An integral means is to be provided to earth isolated circuits so that cables.
3. The system is to be designed as far as possible.11
. BR 8472 and BR 8473.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
(8) (9) Below 3. Therefore. Refer to BR 8470. Where the series of BR is incomplete. LV cables must not be run in the same duct as MV cables. etc. are discharged. Cable ratings are to be calculated as for LV system cables. The preferred type of breaker for MV systems in HM Surface Ships and Submarines is the Vacuum Circuit Breaker (VCB).
3. Equipment enclosures are to be sufficiently robust to contain material expelled in the event of a catastrophic failure.14. Standard. MV cables passing through watertight decks or bulkheads must be provided with bulkhead or deck transits such as decktubes. Consideration is to be given to the catastrophic failure modes of current interrupting devices. BR 8471.15
a. Bulkhead penetrators for MV cables are not available and it is not anticipated that they will be developed .13.13.3 kV the metallic sheath may be omitted provided that the cable is armoured. guidance may be obtained from BR 3021 Volumes 1 and 2. except that the heating effects of harmonic currents must be considered. Cable sheathing and armour must be bonded to the ship's earth. non MOD(N) transits are acceptable.3
Cable Ratings a.
Internally Generated Shock (a)
Maintenance Earthing (a)
3. (1) External Shock Requirements (a) The design of circuit breakers and their mountings are to withstand externally generated shock levels appropriate to the equipment location within the vessel.
Type Tests (1)
3. connected to the ship's hull. Specification for HV Fuse links for Motor Circuit Applications.20
b. ship's motion and toxicity of the material.19
Oil Filled Components
a. In the meantime. except that inter turn insulation is to be tested at Un/3 + 1000 V ac rms. Integral means are to be provided to earth the isolated circuits for maintenance purposes. Sample coils should adequately represent the finished coil to be used in the winding. maintenance burden. MV fusegear enclosures are to be designed to provide containment in the event of fire or fuse cartridge failure. tests are to be agreed between the MOD Sponsor and the machine supplier. c. NES 530 and NES 532.16
a. require special consideration to ensure that the component is adequately rated. The following references are applicable: (1) BS 2692 Part 2 Fuses for Voltages Exceeding 1000 V ac: Expulsion Fuses. Transformers which provide isolation between LV and MV systems are to be provided with a screen between primary and secondary windings.20.
3. Such components must not be used in the MV systems of HM Surface Ships and Submarines. The following standards must also be consulted: BS EN 60298 (1996) and BS EN 60694 (1997). The requirements of BS 4999 Part 144 are to apply. switchboards are to be designed to meet the requirements of NES 501.1
Machines a. BS EN 60644
a. Switchboards should be arranged with supply cables and duplicated services in completely segregated sections to allow continued operation of healthy circuits in the event of a single fault.12
3. Unless superseded by MV requirements.
b. The very high voltages which can be generated when fault current is interrupted by a circuit fuse.
b. where Un is the rated line-to-line voltage.
b. namely.
BS EN 60282 1 High Voltage Fuses: Current Limiting Fuses.17
a. Transformers and switchgear which are filled with mineral insulating oil are undesirable for a number of reasons. Random sample tests are to be conducted to evaluate the insulation system. Machines with Vacuum Impregnated Windings (1) Tests for machines with vacuum impregnated windings are under consideration.
3. A power frequency high voltage test is to be conducted on the completed winding in accordance with BS 4999 Part 143.21 Commissioning/Special Test Equipment
a. a transformer may be used to step down the voltage to levels compatible with the insulation system of the load. A high frequency MV test is to be performed on the individual coils to demonstrate satisfactory withstand of the inter turn insulation to steep fronted switching surges. for applying load.0 17. Refer to BS EN 60071. Provisions for commissioning the MV generation and distribution system are to be considered at the design stages. The requirements for preventive and corrective maintenance testing must also be considered at this stage. The test should preferably be done after the coils are installed into the stator core.6 7. Other equipment is to be tested in accordance with the appropriate British Standard for that equipment. Where there is no relevant standard. Routine Tests (1) Inter turn.20. The test will normally be performed by discharging a capacitor across the coil. Consideration must be given at the design stage to the methods which will be used.
d.1 – Standard Insulation Levels 3. Particular consideration must be given to the method by which load banks may be connected to the MV system. The commissioning of generators will require the use of load banks.
3. Each coil is to be subjected to at least 5 impulses of peak amplitude 3 x Un√(2/3).
c.1. a power frequency high voltage test is to be performed at the value given in Table 3. Power frequency.5 Standard Short Duration Power Frequency Withstand Voltage (kV rms) 10 20 28 38
Table 3. to demonstrate a satisfactory withstand voltage level to earth. Testing will require special equipment for checking insulation. and for measuring performance.13
. Highest Voltage for Equipment (kV rms) 3. Where the voltage rating of such equipment is below the generator output voltage.2 12. Shore supplies will normally be connected to the ship's LV distribution system.2
Other Equipment a.
which are routinely occupied by persons not competent to access such equipment. allowing the MV distribution system to be isolated when the propulsion system is not required. Separation between MV and other cables are to be at least 300 mm.
MV equipment and cable runs must not be accessible in compartments such as accommodation spaces. d.1
b. NES 532.1. YM3889/82. NES 501. NES 516. Access to all compartments containing MV equipment must be limited to persons competent to enter such compartments. The distribution system voltage and frequency regulation must be compatible with the requirement for the LV side of conversion equipment. All persons required to carry out switching operations are to be qualified as Authorised Person(s) (AP). Shore supply and ship alongside facilities must be connected directly to the LV distribution system.1
4. see also Annex A.
e.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
4. Switchboards must be located as close as is practicable to associated generators.
Main ac Electrical Power Supply and Distribution
b. to meet the requirements of DEF STAN 61 5 Part 4. Cables run on cable trays are to be provided with individual overall metallic screens.
4. regardless of any requirements for armoured cables. all MV equipment is to be located such that it is not possible to access the equipment without correct authorisation.
d. also as defined in Clause 2.2
System Configuration a.
4. The generator neutral (star) point must be earthed using high impedance earthing techniques (see Clause 3.
DESIGN REQUIREMENTS/GUIDANCE Related Documents: DEF STAN 61-5 Part 4. Generators are to be connected to the distribution system via `pole linked' circuit breakers contained within associated switchboards. Such trunking shall be used for MV cables only. MV cables must be run separately from LV and signal cables.1. The voltage and frequency rating of main generators for MV systems will be determined by the requirements for propulsion power and by the total system load. feeding the 440 V 60 Hz distribution system. MV distribution systems may be configured as `ring' or `tree' networks dependent on individual ship requirements. with facilities to operate in `split' sections in the event of faults or action damage.1. Systems shall provide maximum equipment availability by provision of the capability of operation with all available generators connected in parallel. All persons required to enter compartments containing MV equipment are to be qualified as Competent Persons (CP). (1) (2) f.2).
c. as defined in Clause 2.
c.1. To meet the requirements of MV safety. Cables are to be run in trunking if further physical protection is required.
The power rating of each converter is to be such that the prospective fault current does not exceed the limitations against which a MV system was initially selected.
4. The required safety measures for working on MV equipment mean that repair and maintenance at sea is difficult and prolonged.2
. The principal requirements are stated below: (1) It must be possible to spread the ship's total MV load between the running generators in order to optimise the efficiency and the maintenance load of the generation system.
The above aims will be achieved by centralised control of the MV supply system from a Primary Electrical Control Panel. The LV distribution system is to be supplied using conversion equipment which converts the MV supply to a 440 V 60 Hz LV supply which meets the . Sufficient separate interfaces are to be provided to ensure that all equipment requirements for Normal. Emergency supply arranagements are incorporated. c.
4. It must be possible to isolate defective parts of the MV supply and distribution system.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
g. requirements of DEF STAN 61 5 Part 4. by using a common droop in a parallel generation system where the prime movers have similar part load efficiencies.
4. providing control and instrumentation for: (1) (2) (3) (4) Generator start and stop. by automatically controlling the droops in a parallel generation system where the prime movers have different part load efficiencies. The conversion equipment must be designed to ensure that the LV system cannot become charged to MV potential under fault conditions. d. Available supplies are able to be re connected as dictated by the prevailing system conditions.
b. At least two methods of synchronisation of any two supply sources.1. This may be achieved.2
Interfaces with the Low Voltage Distribution System
a. The system design is to aim to eliminate any requirement for maintenance at sea.
(2) (3) (4) b. by evenly loading the generators in a split generation system. Supply voltage control. one method being manual. or by some other method.3
4. The control and instrumentation requirements for an MV system are similar to those of the LV Main Electrical Power System and reference should be made to NES 532. Alternative and Emergency supplies can be met.3. Supply frequency control.1
Requirements a. Conversion equipment is subject to the MV safety requirements of Clause 2.
the ship's services requirement will dominate the load.
4. Precautions are to be observed to prevent leakage from the MV system charging the LV system.
c. In an IFEP system.
4. HM Surface Ships and Submarines utilising MV systems will tend to operate with a wide power band.5.1
Safe Operating Procedures a.5. Thus. Where the load is an electrical propulsion system. the power range will be lower than for either FEP or IFEP .6.
4. are not wholly exclusive to MV systems.4. This may give scope for a vessel to have a reconfigurable power system to meet integrity requirements in various ship states. In a FEP system. the integrity requirement of the load may vary with vessel speeds and operations. Thus the design of the MV system must ensure the integrity of the supplies to its various loads.2
Generator Configuration a. In electric cruise or MV ship's services systems.2
Sensing Circuits a.2 identifies and briefly describes generation configurations which are particularly appropriate to systems utilising high power prime movers. Instrumentation transformers are to be fitted with earthed screens between primary and secondary windings.1
Integrity of Medium Voltage Electrical Power Supplies
4. Clause 4. This issue is considered further in Clause 4. The principles of segregating MV and LV circuits must be maintained in the sensor circuits. The guidance provided in NES 532 is generally applicable to MV systems.5
4. to avoid potentially hazardous operating conditions arising.3
.5. an IFEP system will have a slightly narrower power band requirement than a FEP system. sited within or near to the main MV switchboards.4.4
4. The design of the control scheme must provide safeguards as far as practicable. Monitoring the MV system requires sensors to interface between LV and MV circuits. These configurations. This will normally be accomplished by the use of current and voltage transformers. In the case where the LV system derives power from the MV system. However.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
(5) Remote electrical control of all main breakers and illuminated indication of the state of all main breakers. the maximum speed will require a much greater power than the normal speed.
Reversionary control of main supply generators and switchgear is to be provided by Secondary Electrical Control Panels. propulsion load demands will dominate the load requirement at high vessel speeds whereas at low vessel speeds. b. particular attention must be paid to maintaining the continuity of essential LV supplies. The integrity requirements of any main electrical supply system must be such that the integrity requirements of the electrical supplies for all the loads are met. provided by the use of discrepancy switches. some require further consideration.
b. The high power density of plant required by MV generation systems in fast warships using electric propulsion, together with the wide power band, suggests that the generation plant will comprise either: (1) (2) (3) c. d. A small number of high rated prime movers whose efficient power range is wide; A range of prime movers which can together, supply the power band efficiently; A combination of (1) and (2).
The generators may be arranged in a number of schemes, some of which are discussed below. A split generation scheme has been traditionally employed in the ship's services distribution systems of HM Surface Ships and Submarines. But with the predicted increasing loads of future vessels, split generation appears to have been superseded in concept studies by variants of parallel generation. However, split generation may still be appropriate for propulsion to maximum vessel speeds in order to reduce distribution and fault currents. Parallel Generator Operation (PGO) has become the standard method of generation in commercial vessels with MV systems. Here a power management system can automatically run up and shut down generators, and start and stop loads to ensure that the generation system operates efficiently within its capacity. Minimum Generator Operation (MGO) operates the generators in PGO mode until the load can be supplied by one generator. Then the system operates in Single Generator Operation (SGO) mode. An energy storage system may be required to support the load on failure of the single running generator and until a standby generator can be brought to load. Energy storage specifications would depend on the availability requirements of the various power system loads. NOTE It may be possible to run a FEP system in MGO without energy storage.
It may be cost effective, or otherwise desirable, to be able to re configure the generation configuration for different operational activities and vessel speeds. Here re configuration could be automatic or manual.
a. MV systems may be required to supply one or more of the following types of load: ship's services loads; electric propulsion load; pulsed loads; other miscellaneous loads. The Availability and Reliability (A&R) requirements of the MV supplies will be stated in the STR. The maintainability requirements for MV systems are the same as for LV requirements and are discussed in NES 532. There are likely to be different requirements for the different loads, for different operational activities and for different vessel speeds. These A&R requirements will then impact on generator selection, generation configuration and amount of re configuration.
c. A&R requirements for LV supplies will be stated in the STR and will be in accordance with NES 532. However, where the MV system supplies the LV system, `generators' referred to in NES 532 will be MV/LV converters plus any additional LV generators and should be considered as `LV sources'. MV/LV converters may be transformers, power electronic converters or rotary converters.
The integrity of the LV supplies will inevitably depend on the A&R of the MV/LV converters, the number and rating of the MV/LV converters and the A&R of the supplies to the MV/LV converters. Therefore, the design of the MV system, its method of operation and the number and specification of the MV/LV converters, will be depend on the LV system A&R requirements stated in the STR. The prime contractor should determine A&R figures for the MV/LV system interface to apply at the point of common coupling or some other agreed point (or points). DME/ME242 will arbitrate if necessary for both the A&R figures and the agreed points. Where the MV system provides power for propulsion, the STR will state A&R figures for propulsion capability. This may be in terms of the A&R for a given shaft power or a given vessel speed and should include different A&R for different vessel speeds and operational activities. If the MV system supplier does not provide the propulsion plant required, the various contractors must agree A&R requirements and the points in the MV system at which they apply, e.g. at the input terminals of the propulsion plant. Again, DME/ME242 will arbitrate if necessary. The A&R requirements placed on the MV system sub prime contractor will influence MV generation and distribution system design and operation. In summary, the STR will state the availability and reliability requirements for various loads, vessel speeds and operational activities. Measurement points, i.e. points where the A&R figures will be applicable, will also be stated. The STR may present its requirements in a form similar to Tables 4.1 and 4.2.
Load State Vessel Speed S eed (knots) Vessel O erating Operating Activity Propulsion
Medium Voltage System Load Low Voltage Supplies
Availability Reliability Measurement Comment Availability Reliability Measurement Comment Point1 Point1
0 3 8 15 19 23 25 27 30 31
NOTE The measurement point is the agreed location at which the availability and reliability of the MV supply to the given load must apply.
Table 4.1 – Integrity Parameter Requirement Format for Medium Voltage System Propulsion and Low Voltage Supplies
Load State Vessel Speed S eed (knots)
Miscellaneous MediumVoltage System Loads1
Vessel Name of Load 1: Name of Load n: O erating Operating Activity Availability Reliability Measurement Comment Availability Reliability Measurement Comment Point2 Point2
NOTE 1. Miscellaneous loads include pulsed loads. 2. The measurement point is the agreed location at which the availability and reliability of the MV supply to the given load must apply.
Table 4.2 – Integrity Parameter Requirement Format for Medium Voltage System Miscellaneous Loads
will be stated in the STR.e.
Levels of Over-voltages Experienced in a System
a.assuming that they meet the environmental requirements. which are of an atmospheric origin and internal over voltages which result from faults and operation of the system. In this case.
c. a distinction is made between external over voltages.
4. assuming the electrical system is in accordance with the requirements of NES 501 and NES 516. The method of assessing fault levels in MV systems will not differ from that used to assess LV system fault levels. When designing to meet the A&R requirements stated in the STR in accordance with Clause 4.g. the shutters must have the facility to be locked. reference should be made to NES 532. if isolation is by means of shutters.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
4. i. The breakers will have the facility to be earthed when disconnected from the supply. detailed alternative supply requirements for the supply of specific loads or systems. Breakers of the same frame size (and voltage rating) are to be fully interchangeable (within two hours). The causes of internal over voltages experienced in electrical systems have been identified as: (1) (2) Generator Automatic Voltage Regulator (AVR) faults.9. the designer should determine whether the provision of alternative supplies will offer the most effective solution. However. the sponsor may require specific alternative supplies to be provided.
4.6. According to their source. Interruption of short circuit fault currents by fuses.
b. Hence. lightning strikes are not considered as a cause of over voltage in HM Surface Ships. The isolation facilities must be lockable.
4. Thus truck breakers could be used for some or all MV breaker frame sizes if required . Over voltages are generally transient voltages which are greater than the maximum permissible continuous operating voltages of electrical systems.9
Fault Level Assessment for Medium Voltage Systems
General a. External over voltages. Functional tests must be able to be carried out on the breaker while it is fitted in the switchboard. Breakers must have the facility to isolate faulty sections to allow maintenance to be carried out on the faulty equipment. It is not a requirement for MV and LV breakers to be interchangeable.7
Provision of Alternative Supplies
a. Main Circuit Breakers: (1) The number of different frame sizes of breakers used in the MV supply system is to be kept to a minimum.8
Issues Specific to Medium Voltage Supplies
4. e.7
Multiple re ignition during circuit breaker opening.8
Generator AVR fault Solid earth fault1 Intermittent earth fault2 Fuse current chopping Interrupter current chopping Pre strike Multiple re ignition Where: U Z I K = = = =
5( 2U
BS 2692 : Pt 1
3) Z1)( 2U 5.0 8. Chopping of current to inductive loads. 2. (Reference YARD Memo. Arc suppression coils.3 – Characteristics of System Over-voltages 4. YM3889/82). Low impedance neutral point earthing.5 4. Only applicable to unearthed neutral and high resistance earth neutral systems.
Switching and Earth fault over voltage limiting devices:
The methods of deriving the levels of over voltage created by the above phenomena are detailed in Table 4. Thyristor switching.7 5. Cause Derivation
2U 3 3)
Frequency Power frequency Power frequency kHz kHz kHz kHz kHz
K Factor 2.3.
Table 4. Shunt reactors.12
a.75 8( 2U 3)
Line Volts (rms) Load Surge Impedance Chopping Current Ratio of over voltage (peak) to phase voltage (peak)
NOTE: 1.11 Means of Reducing Over-voltages
a.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
(3) (4) (5) (6) (7) e.4 5. Pre strike during circuit breaker closure. For example: (1) Power frequency voltage rise limiting devices: (a) (b) (c) (2) (a) (b) (c) Voltage regulators for generators. Over voltages can be limited by a variety of design measures and/or arrangement of the system circuits. Tap changers for transformers.3( 2U 3)0.
4. Restrike free circuit breakers. An explanation of the pu base system along with a fault level example and procedure can be found in NES 532. Earth faults. Only applicable to unearthed neutral systems.0 1.
Xd''.
Fault Level at point A: = =
MVA(base) (0.6 kV base. Calculation of Impedance at point B: ZB = Impedance at point A + Cabling Impedance = 0.6 10 3
= 34. The values in brackets are the converted pu values after using the above formulae and base values.37 kA g. are given as a pu value on the machine rating. B and C (Figure 4.0664 pu
4. The peak asymmetrical fault current at point A: Isc = 2 2I rms symmetrical = 2 2 x 34.22 kA h. This is converted to a pu value on the system base as follows:
X d pu + X d pu(rating) V 2(rating) MVA(rating) MVA(base) V 2(base)
Other parameters such as cable resistances are often given as ohmic values. the circuit resistance may be omitted to simplify the calculations.95 10 3 6.
Calculation for a fault at point A: ZA = 0.00066)j0. Often machine parameters such as sub transient reactance.95 MVA f.0155 = 0.
e.0509 + 0.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
b.0509)
= 392.9
.0509 NOTE In many cases.373 x 103 = 97. 6. where resistance is negligible compared to reactance.000066 + j0. The rms symmetrical fault current at point A is calculated as follows: VA = 3 V LIL Thus I L + VA
6 + 392.0192 + j0.1) have been calculated using a 20 MVA.01986 + j0.
Calculations: The fault levels at points A.0509) (20 10 6) (0.00066 + j0. These can be converted to pu values as follows:
Rpu + R W MVA(base) V2(base)
m.6 = j0.775 ë36.34o
= 288. The rms symmetrical current at point C: I = 25.408 kA l.600 MVA j.385 kA
4.6 106 10 3
= 25. The peak asymmetrical current at point C: I=2 2
2.600 3 6.257 kA o.775ë36. Impedance at point C: Zc = Impedance at point B + Impedance of Equivalent Transformer = 0.0693 ë73.806
3 10 6 6. Fault Level at point B:
+ + MVA(base) 0.806 MVA n.10
.246 kA = 71.95
= 25.01986 ) j0.0664 + 0.4664 pu
+ 0.0664 20 106 0.61986 + j0.4 = 0.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
Fault Level at point C:
+ 20 10 6 0. The peak asymmetrical fault current at point B: I = 2 2 x 25.257 10 3
= 6.01986 + j0.246 kA k.6 10 3
= 2. The rms symmetrical fault current at point B:
I + 288.
0.03W (0.0003W (0.126 (0.0018)
Motor Load 22 MVA Xm = 3.004W (0.0183) 0.006W (0.0137)
1 MVA Transformer R = 3% X = 2%
Ship’s Services C
Figure 4.0003W (0.000137) 0.000918) 0.04W (0.11
.006W (0.00275) X X
25 MVA Xd” = R = X = 0.1008) 0.1 – Typical Simple Network
4.000137) 0.002W (0.126 (0.64 (3.1008) 0.31)
0.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
25 MVA Xd” = R = X = 0.
Medium Voltage Creepage and Clearance
Insulation Co-ordination a.10355
j 0.12
.6 Equivalent Transformer j 0.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
INFINITE BUSBAR Equivalent Generator Equivalent Motor
0. with due consideration for system protection levels and the service environment.13
4.10355
A 0.000137
j 0.0192 Cabling Impedance
j 0.000137 j 3. Guidance on insulation co ordination is contained in BS EN 60071.2 – Equivalent Impedance Diagram 4.0155
0. The selection of system insulation levels must take into account the voltages which may appear on the system under all conditions.
suitable enclosures may reduce the pollution level category. the values given in Table 4. Normally. Nominal System Voltage (volts) 1100 2400 3300 4160 6600 11000 13800 15000 Minimum Clearances Between Phases and to Earth (mm) 25 40 50 60 65 80 85 95 Minimum Creepage Between Phases and to Earth (mm) 25 40 50 70 90 125 140 150
b. pollution level IV will apply. mechanical shock. Designers must also take account of the most unfavourable combination of manufacturing tolerances and any movement or deformation which may occur when the equipment is subjected to ageing.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
Taken from IEE Recommendations for the Electrical and Electronic Equipment of Mobile and Fixed Offshore Installations. The minimum creepage and clearance distances provided for all connections.2
Creepage and Clearance a. Where the information required to perform the calculations of BS EN 60071 is not available. however.
Table 4.4 – Minimum Creepage and Clearance Distances
4.4 may be used as minimum values. terminals and similar bare `live' parts are to be determined in accordance with the requirements of BS EN 60071 1 and BS EN 60071 2. temperature. vibration and system fault conditions.
This NES has been compiled using the MV technology currently used within commercial environments. b.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
5. corporate knowledge and experience will become available and as such will be included within this section. there is at present no relevant knowledge and experience which fits within this section.1
5. Due to the recent introduction of MV technology into the Royal Navy. As this technology is developed for use on naval platforms.
ANNEX A.Test Procedures (English) Application Guide for the Selection of Fuse Links of High Voltage Fuses for Transformer Circuit Applications (includes Amdt 1) Tests for electric cables under fire conditions Recommended Practice for Electric Power Distribution for Industrial Plants Recommended Practice for Protection and Co ordination of Industrial and Commercial Power Systems Recommended Practice for Industrial and Commercial Power Systems Analysis Recommended Practices and Requirements for Harmonic Control in Electrical Power Systems Regulations for the Electrical and Electronic Equipment of Ships. RELATED DOCUMENTS
. Recommendations for the Electrical and Electronic Equipment of Mobile and Fixed Offshore Installations Electricity at Work Regulations Health and Safety at Work Act 1974 BS 2692 BS 4999 Fuses for voltages exceeding 1000 V ac: Part 2: Expulsion Fuses General Requirements for Rotating Electrical Machines: Part 143: Specification for Tests Part 144: Specification for the Insulation of Bars and Coils of High Voltage Machines Including Test Methods Safety Signs and Colours Low Voltage Switchgear and Control Gear Assemblies Specifications for conductors in insulated cables and cords Insulating and Sheathing Materials of Electric Cables Specification for 600/1000 V and 1900/3300 V Armoured Electric Cables having Thermosetting Insulation and Low Emission of Smoke and Corrosive Gases when affected by Fire Specification for Elastomer Insulated Cables for Fixed Wiring in Ships and on Mobile and Fixed Offshore Units Insulation Co ordination Current Limiting Fuses ac Metal enclosed switchgear and control gear for rated voltages above 1 kV and up to and including 52 kV Specification for High Voltage Fuse Links for Motor Circuit Applications
BS 5378 BS 5486 BS 6360 BS 6469 BS 6724 BS 6883 BS EN 60071 BS EN 60282 1 BS EN 60298 BS EN 60644
A. The following documents and publications are referred to in this NES: Lloyd's Rules IEC 60 2 IEC 787:1983 IEC 331 IEEE Std 141 IEEE Std 242 IEEE Std 399 IEEE Std 519 IEE Regulations Lloyd's Register .Rules and Regulations for the Classification of Ships High Voltage Test Techniques .
Common Test Methods Ship Safety Management System Handbook: Volume 1 Policy and Guidance on MOD Ship Equipment Safety Management Electromagnetic Compatibility Electrical Power Supply Systems below 650 Volts: Part 4: Power supplies in HM Ships Wires. Thin Wall Insulated. Limited Fire Hazard (LFH) Sheathed Requirements for Electric Cables.2
. Electric.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
BS EN 60694(1997) BS EN 60811 JSP 430
Common Specifications for High Voltage Switchgear and Control Gear Standards Insulating and Sheathing Materials of Electric Cables. Electric: Part 1: Pressure Tight Ethylene Propylene Rubber (EPR) or Silicone Rubber Insulated. High Temperature Zones and Limited Fire Hazard Sheathed Requirements for Main and Distribution Switchgear Guide to the Design of Electrical Supply and Distribution Systems in Surface Ships (Restricted) Requirements for Design and Testing of Equipment to Meet Environmental Conditions (UK Restricted) Shock Manual (Metric) Volume 1 Volume 2 Shock and Vibration Manual Mounting System Design Installation and Maintenance Naval Standard Range Mounts for Equipment Installation (to Attenuate Mechanical Shock or Vibration) Miscellaneous Mounts for Equipment Installation (to Attenuate Mechanical Shock or Vibration) YARD Memo Neutral Earthing of Marine Electrical Power Systems 1982
DEF STAN 59-41 DEF STAN 61-5 DEF STAN 61-12 NES 501 NES 502 NES 512 NES 516 NES 517
NES 525 NES 527 NES 530 NES 532 NES 1004 BR 3021
BR 8470 BR 8471 BR 8472 BR 8473 YM3889/82
A. Cords and Cables. Electrical and Associated Items Guide to Lightning Protection in Surface Ships (Restricted-Commercial) Requirements for Cables. Limited Fire Hazard Requirements for Cables. Electrical .Metric Units: Part 31: Limited Fire Hazard General Requirements for the Design of Electrotechnical and Naval Weapon Equipment (Restricted) Requirements for Electrical Installations Guide to Cables. Fire Survival. Chlorosulphonated Polyethylene (CSP).
. ABBREVIATIONS AND DEFINITIONS
B1. For the purpose of this NES the following abbreviations apply: AE AP APC AVR A&R CME CP CSP DEF STAN DLO DME/ME DPA EMC EPR EOW FEP HOFR HV IEE IFEP ITO LFH LOA LOB LV MEO MGO MOD MOD(N) MTPU MV NES PCC PFT PFW Authorising Engineer Authorised Person Authorised Person in Control Automatic Voltage Regulator Availability and Reliability Circuit Main Earth Competent Person Chlorosulphonated Polyethylene Defence Standard Defence Logistics Organisation Director Marine Engineering/Marine Engineering Defence Procurement Agency Electromagnetic Compatibility Ethylene Propylene Rubber Engineering Officer of the Watch Full Electric Propulsion Heat resistant. Oil resistant and Flame Retardant High Voltage Institute of Electrical Engineers Integrated Full Electric Propulsion Inverse Time Over-current Limited Fire Hazard Limitation of Access Lock Out Box Low Voltage Marine Engineering Officer Minimum Generator Operation Ministry of Defence Ministry of Defence (Navy) Motor Thermal Protection Unit Medium Voltage Naval Engineering Standard Point of Common Coupling Permit for Test Permit for Work
Parallel Generator Operation Root Mean Square Royal Navy Single Generator Operation Statement of Technical Requirements Total Harmonic Distortion Unit Production Cost Vacuum Circuit Breaker Voltage Transformer Zero Halogen
For the purpose of the NES the following definitions apply: Medium Voltage I2R Any ac voltage between 1 kV and 15 kV Heating losses referred to current
PGO rms RN SGO STR THD UPC VCB VT ZH B2.
2.6.9 3. Rectifiers Starting and inrush currents Local balance Spikes. 3.5. c. c.5 3.10 3.6.
1. Considerations in selecting earthing methods Unearthed neutral systems High imbalance neutral earthing Maintenance earthing
MV cables and conductors
C. b. d.8 3. c. Each item is to be marked either: = included NA = not applicable
Check No.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
ANNEX C. e.4 3.13
Susceptibility to waveform quality: a.3 1.3 1.5.1 1.5.3 and 3.5 1.4 1.1 and Annex E 3.3 1.2 1.6. 3.4 1.1
.6 3. b. This Check List is to ensure that certain aspects of this Naval Engineering Standard are consulted when preparing a procurement specification for a particular application.1 3.7 3.6. f.1 1. d.6. Current and Contact Protection Parallel feeders Earthing Policy for MV systems in HM Surface Ships and Submarines: a. 2. surges and sags Voltage and current line to line imbalance Harmonics Notches Voltage ripple Modulation flicker
Clause No. b.
Safety and rules for working with MV equipment MV electrical power requirements Voltage.2 1.6 2.6.
Quality of MV power supplies Compliance with DEF STAN 61-5 Contribution to waveform quality: a. PROCUREMENT CHECK LIST
Notes: 1. Clauses where a preference for an option is to be used or where specific data are to be added are included in the Check List.
.16 3.5 4.13
C.10 and 4.21 4.15 3.3 4.17 3.14 3.2 4.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
Bulkhead penetrators Circuit breakers Switchboards Transformers Fuses MV Testing Commissioning/Special Test Equipment Mains ac electrical power supply and distribution Interfaces with LV distribution systems Instrumentation and control Integrity of MV electrical power supplies Power system integrity Levels of over voltage in systems and methods of reducing Fault Level MV creepage and clearances
3.12 4.18 3.11 4.20 3.1 4.
depth and recovery time Frequency surge. NES 607 refers to the STR on many of these topics. The requirement for this topic is stated in another section of the STR (or in another STR). waveshape. depth and recovery time Voltage surge. energy Limits of harmonic distortion NOTES: 1. 4. depth and recovery time dc offset Voltage spike. 2. Tick one column per parameter STR1 N/A2 Contractor3 Diff4
Table D1 – Statement of Technical Requirements Compliancy Matrix – Quality of Power Supplies
D. This Annex provides a checklist of salient points which need to be considered when writing an STR. 3. This aspect of the design. or value of the parameter. is left to the discretion of the contractor. peak.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
ANNEX D. Requirement for this topic is stated in the STR.1
. depth and recovery time Fixed frequency system and nominal frequency Variable frequency system and frequency range Frequency tolerance Frequency modulation Frequency sag. A requirement for this topic is not applicable for this project. Topic or parameter Quality of Power Limits Fixed voltage system and nominal voltage Variable voltage system and voltage range Average line-to-line voltage Line voltage unbalance tolerance Maximum voltage deviation from average Voltage modulation Voltage sag. STATEMENT OF TECHNICAL REQUIREMENTS COMPLIANCE MATRIX
. or value of the parameter. 3. This aspect of the design. The requirement for this topic is stated in another section of the STR (or in another STR). 4.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
Topic or parameter User Equipment Constraints Switch ON/start up current transient limitation Duty cycle and period of pulsed loads Harmonic distortion limits Commutation notch depth and duration restrictions Permitted out of balance load on a 3 Phase supply Earth leakage currents Conducted and radiated EMC limits Equipment short circuit fault current rating NOTES: 1.
Table D2 – Statement of Technical Requirements Compliancy Matrix – User Equipment Constraints
D. is left to the discretion of the contractor.
Tick one column per parameter STR1 N/A2 Contractor3 Diff4
A requirement for this topic is not applicable for this project. Requirement for this topic is stated in the STR. 2.
This aspect of the design.
Table D3 – Statement of Technical Requirement Compliancy Matrix – Miscellaneous Topics
D. or value of the parameter. is left to the discretion of the contractor. 2. Requirement for this topic is stated in the STR. 4.3
A requirement for this topic is not applicable for this project. The requirement for this topic is stated in another section of the STR (or in another STR).INT DEF STAN 02–607 / ISSUE 1 (NES 607)
Topic or parameter Availability and Reliability A&R requirements for LV supplies A&R requirements for propulsion A&R requirements for MV supplies to miscellaneous loads including pulsed loads Applicability of Standards EMC DEF STAN 59-41 Environmental NES 1004 Hazards ARM Noise and Vibration Shock General Method of earthing Specific alternative supply arrangements Specific requirements for parallel and back-up supplies Specific protection requirements such as reverse power protection Specific testing requirements Tests for machines with vacuum impregnation NOTES: 1.
E2. RULE 1 RULE 2 RULE 3 RULE 4 RULE 5 RULE 6 RULE 7 RULE 8 RULE 9 Access to MV Compartments and Equipment Access to Confined Spaces Key Arrangements Duplicate Keys MV Switching Indicating and Recording of MV Switching Safety Locks Caution and Danger Notices Precautions to be Taken Before Working on MV Systems Page E.1
. RULE 15 Work on MV Metal Clad Switchgear E16.3 E. E3. E9. E4. RULE 12 On Completion of Work E13.2 E.9 E. SAFETY RULES FOR WORK ON OR NEAR MEDIUM VOLTAGE EQUIPMENT CONTENTS
Rule E1. RULE 17 Work in MV Compartments Containing Exposed Live MV Conductors E18.2 E. RULE 14 Remotely and Automatically Controlled Equipment E15. RULE 10 Earthing E11.9 E.13 E.4 E.12 E. RULE 11 Permits for Work and Test and Limitations of Access E12.14
E10.6 E. E5. RULE 16 Work on MV Distribution Transformers E17. RULE 20 Fire Protection Equipment E20.9 E.5 E.4 E.13 E.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
ANNEX E.3 E. E6. E7. RULE 18 Work on Ancillary Equipment E19.5 E. RULE 21 Work on MV Cables
E. E8.2 E.11 E.9 E. RULE 13 Testing MV Equipment E14.4 E.
and when not in use. under the control of the APC. Access to these compartments requires prior approval of the APC.
E3. a confined space must conform to the requirements of MOD safety rules covering confined spaces.
E2. Exceptionally. All MV compartment and switchgear keys are to be uniquely numbered and all key numbers listed in the MV Key Register. Where one or more persons are required to work in a confined space. to whom it is issued and reason for its issue must be entered in a separate register kept by the AE who must also muster the keys regularly. chamber.
b. cubicles or cells are normally to be kept locked. be locked shut. When dangerous fumes are liable to be present. and exposed flames or smoking are prohibited in. RULE 3 . All unmanned compartments containing MV equipment are to be fitted with a unique lock.
All spout shutters not required for immediate work or operation must. A CP acting under the direct supervision of an AP who has adequate knowledge or experience to avoid danger and who has been instructed in the action to be taken in the event of an accident. Persons who do not have adequate knowledge or experience to avoid danger and who have not been instructed in the action to be taken in the event of an accident. All unmanned compartments containing MV equipment are to be kept secure to deny unauthorised access.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
b. an extra person is to be kept on duty outside the confined space and that person is to keep in touch with the worker(s) inside the confined space. cubicle or cell in which a live conductor is exposed except: (1).
c. The extra person must not enter the confined space at any time. No person may open or enter any such enclosure. its number.
c. RULE 2 . the key to the press being in the possession of the APC at all times.
(2). Barriers (including plates) denying access to MV enclosures. use of suitable natural or forced ventilation) and the consent of an AP obtained.g. if not otherwise made inaccessible. An AP accompanied by another person who has adequate knowledge or experience to avoid danger and who has been instructed in the action to be taken in the event of an accident. All locks are to belong to a single suite for which a master key is available. service. each key being kept on a key ring with a tally attached giving the key number and the name of the compartment or switch to which it applies. No person is to enter. Master keys held for the system are to be issued by the AE to specific persons. The recipients of the issue are to sign a receipt for each key. from whom access keys are to be drawn.ACCESS TO MEDIUM VOLTAGE COMPARTMENTS AND EQUIPMENT a. b. any confined space unless adequate precautions have been taken (e.KEY ARRANGEMENTS a. and work within. Details of each master. RULE 1 . these precautions are to include testing for gas. keys must be kept in a locked security cupboard or safe. or absence of oxygen by means of an approved detector.ACCESS TO CONFINED SPACES a. No key is to be removed from the vessel. chambers. All entry to. and should any incident occur the alarm is to be immediately raised. must not enter any MV compartment manned or otherwise. AP with master keys do not require prior approval but should inform the APC of their presence in the compartment.
E. When not issued to an AP or CP all keys are to be kept in a locked key press .
RULE 4 .
E. Any circuit breaker opening under fault conditions should if practicable. Security arrangements for safety locks and keys issued to an AP are covered in detail in Rule 11. the keys are to be returned to the APC. Before any switching is carried out on any system which may affect other systems. RULE 5 .
c. the APC will countersign the entry and issue the necessary keys to the AP . and signed by him: (1). is to be reported to the APC as soon as possible after each operation. be checked for signs of distress. If duplicate keys for any MV equipment or compartment are held for emergency use.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
d. When switching or other work is being arranged between the APC and AP(s). The AP is to report back the instruction prior to taking the action.DUPLICATE KEYS a. the switching being recorded by all concerned. When a requirement exists to hold duplicate or master interlock keys. Date and time of issue. When keys are issued for any purpose. g.
f. Nature of work requiring issue of keys.MEDIUM VOLTAGE SWITCHING a. Details of the issue of duplicate keys must be kept in accordance with Rule 3. All switching whether to instructions or with consent. (2). the date and time being recorded in the register and countersigned by the APC. the following details are to be entered in the MV Key Register by the person requiring the keys. any objections must be referred to the AE for a decision before the operations are commenced. When switchgear shows any sign of distress. by the authorised key holder. b. f. or when there is a danger to life or any other case of emergency.
E5. When the APC gives instructions for MV switching to be carried out he is to communicate with the AP who is to carry out the switching.
After the entry has been completed. c.
e. to confirm his understanding of the instruction. The circumstances of an occurrence necessitating any emergency switching are to be reported at the same time in accordance with Rule 6. h. Switching to the instructions of the APC or with his consent is to be carried out without undue delay. No MV switching is to be carried out without the prior sanction of the APC except for agreed routine switching or in case of emergency. Making live or dead by signal or pre arranged understanding after an agreed interval of time.3
. they are to be kept in a separate locked key press in the office of the Senior AP or other defined location. the APC authorising the switching is to communicate with the Control Engineer of the systems concerned. these should be held by the AE in a separate locked key press and only used under his direct supervision with the sanction of the APC. Keys required.
E4. its condition must be reported immediately to the APC and it must be examined before further operation. is forbidden.
b. On completion of the work. (3). e. Direct communication is required at all times during remote switching operations.
Barriers and Screens must only be fixed or moved under the immediate supervision of an AP . They may be the normal equipment locks or additional locks specifically provided for the purpose. additional temporary Barriers/Screens are to be erected. Hand dressed displays are to be amended only and as soon as possible after completion of the MV switching operation has been reported by the AP concerned. Danger Notices. The keys for normal equipment locks are to be kept in the key press required by Rule 3. All communications relating to the operation of the MV system must whenever practicable. RULE 7 . d.
E. location and identity of the switch or switches concerned. links and carriers are to be removed and kept in custody of the AP in charge of the work or the APC. preferably using a safety lock. or links. is to be confirmed by signature of the APC at the end of the watch. the date. if completed by his deputy.
E7. selector switches. Where necessary to physically define and/or restrict access to the working area.
b. Each safety lock is to have only one key which is different from all other safety lock keys in use. on all switchgear controlling the equipment which has been made dead and upon which work is to be carried out. additional safety locks and their keys must be kept in a key safe. All AP carrying out MV switching or linking operations are to provide the APC or his delegated representative with full particulars of those operations as soon as possible after they have been completed. RULE 6 . etc. operating handles. d. in the possession of an AP or the APC. The log book. RULE 8 . or other safe place. Safety locks are to be used when making a system or equipment safe prior to the issue or PTW.CAUTION AND DANGER NOTICES a. c. Such custody is to be equivalent to that provided by a key safe. the operation and the reason for all such operations carried out during his shift duty.
.g. When not in use.
E6. where the circuit on which work is to be carried out could be energised. The APC or his delegated representative is to record in the log book provided for the purpose. for locking off shutters.INDICATING AND RECORDING OF MEDIUM VOLTAGE SWITCHING a. or by other approved method. Caution Notices must be fixed. When the circuit on which the work is to be carried out is controlled only by fuses.
e. The APC is to be responsible for the correctness of the supervisory display of the systems in the Main Control Room. or other approved record. the fuses. Every message is to be repeated in full back to the sender to ensure that the message has been accurately received.SAFETY LOCKS a. The APC must check for correct indication of any automatic monitoring system. time.
E8. Caution Notices. be written down or recorded. e. Danger Notices must be attached (where applicable) on or adjacent to live equipment at the limits of the zone in which the work is to proceed.
2. or in any way interfere with MV equipment such as busbar connections. Where (1).1.
d. or between such points and the point(s) of work. and then only by an AP accompanied by another person who has adequate knowledge or experience to avoid danger. cleaning. NOTE The approved pattern link stick is one fitted with a porcelain or similar insulator between the brass hook and the handle.
e. or cable trays containing MV cables unless and until personally instructed by. it is to be done: (1). Circuit Main Earth When MV equipment is to be discharged and earthed in accordance with Rule 9c. by the use of a circuit breaker or specially provided earth switch to make the earth connection. connected to the hook is to be of not less than 70 mm2 conductor cross section. No person is to touch the electrical insulation of MV busbars. RULE 9 .PRECAUTIONS TO BE TAKEN BEFORE WORKING ON MEDIUM VOLTAGE SYSTEMS a. the trip feature must be rendered inoperative before closing. No person is to undertake any repairs. The earthing cable. the circuit breaker or earth switch must be locked in the earthed position. (2). c.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
E9. maintenance. is not practicable. (3). windings or conductors unless and until the equipment has been discharged to earth and connected to earth. an AP .5
. transformer connections. the MV equipment is to be tested to ensure that it is dead and may then be discharged and earthed by an earthing lead applied by an approved means in accordance the Rule above. (5). work on. RULE 10 . When a temporary earthing arrangement is required. while it is in Circuit Main Earth (CME). Efficiently connected to earth at all points of disconnection of supply to such equipment. a. Where practicable. Screened when necessary to prevent danger and Danger Notices fixed. the link stick temporarily earthing a conductor is to be kept in position until earthing cables have been securely attached. a. Isolated and all practicable steps taken to lock off from live conductors. Pre Requisite: It is the duty of the AP issuing the Permit to ensure that the following provisions are complied with. on any part of MV equipment unless that person is fully conversant with the nature and also the extent of the work to be done.
E10. b. When the circuit breaker is used. No person is to touch. After closing.
E10. that part must be: (1). Before any of the above procedures are carried out on any part of a MV system. Released for work by the issue of a PFW or PFT.EARTHING E10. The free end earthing clamp shall be of an approved type and able to carry a current to earth equivalent to the cable capacity. and under the supervision of.
Only the approved pattern of link stick is to be used for discharging and earthing a conductor.
(2). Dead. alteration or such work.
Operation No MV earthing switch must be operated or CME connection attached or removed except with the consent of the APC. (4). machine windings. and who has been instructed in the action to be taken in the event of an accident. unless this is impracticable.
NOTE Additional earths applied after the issue of a PFW or PFT may be attached or removed by a CP The status of these earths should be given to the APC . a. time of application. b. RULE 11 . Earthing leads are to be connected to the earth system before being secured to the phases. (6). a. A PFW or PFT may only be issued by the AP under whose supervision the work is initiated and is to be issued before any work is carried out on any equipment forming part of. For the purpose of earthing on spout contacts of metal clad switchgear. Recording of Circuit Main Earths Each operation must be reported to the APC as soon as possible after completion and the date.PERMITS FOR WORK AND TEST AND LIMITATIONS OF ACCESS E11.
E11. they are to be disconnected from the phases first and the earth system last. and where practicable. a.4. an LOA is to only be issued with the sanction of the APC. Authority for Issue A PFW or a PFT may only be issued with the sanction of the APC who must retain in his custody a written record of the issue of each Permit and its cancellation.
(2). Removal of CME must be similarly reported to the APC and the date and time recorded.
E11.2. When earthing leads are being removed. always examined for defects immediately prior to use. even if work is to be carried out on one phase only. Verify that the circuit is not live. The precise location of each CME shall be recorded on the PFW or PFT. They must only be secured to the phases by an approved means. precise location recorded in the MV switching record. All phases are to be earthed. The insertion of the hand or any tool into contact spouts for this purpose is forbidden. the AP under whose supervision the work is initiated must first prepare and agree with the APC a Safety Programme detailing the activities considered necessary to make the equipment safe.
Procedure for the use of Earthing Leads The procedure to be followed when using earthing leads is: (1). Procedure for Issue and Receipt For all programmed work or tests on MV equipment. or which may be energised from a MV system. E10.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
E10. only approved appliances are to be used. Earthing leads are to be properly maintained. Earthing leads must not be applied in any cell or compartment in which there is any exposed metal live at MV. There is to be no more than one extant master document for a switching sequence. For work in the vicinity of live MV or control equipment. a. Care must be taken to ensure that a good contact is made.
c.3. A LOA is to be issued by an AP when verbal instructions are not considered sufficient and a PFW is not relevant. at each change.
(3). (2).
E. the indicator itself being tested immediately before and after the verification.
(7).6
.1. (4). and inspected and approved for use annually by an AP . (1). (5). test by means of a potential detector of an approved type.
and Rule 9. the AP is to: (1). the earth(s) which may be removed for testing purposes.
E. i. and for a PFT.
h. A LOA is to be issued to the CP in charge of the work who. The APC and CP should each retain a LOB key throughout the work process. Having drawn the relevant keys the AP is to proceed to the MV equipment upon which the work is pending and cause the equipment to be made safe in accordance with the Safety Programme. k. The secured LOB must be placed in key safe in the custody of the APC. is to initial any special instructions or safety measures noted on the LOA and sign its receipt and the duplicate. Demonstrate to the satisfaction of the CP that the equipment is dead and safe to work on or test. d. each having a unique key.
g. Any special safety instructions or safety measures. The original of the Permit is to be issued to. The identity of each switch to be operated. Before issuing the Permit. The Safety Programme (Annex 2) which is to be completed in duplicate is to include: (1). Particulars of the complete sequence of operation. is to initial any special instructions or safety measures noted on the Permit and sign its receipt and the duplicate.
The agreed Safety Programme is to be signed by the AP and sanctioned by the APC. must be secured by three individual locks. The person in charge to whom the LOA is issued is to be a CP who is to retain the LOA in his possession at all times while the work is in progress. the AP initiating the work must create a PFW or PFT from the appropriate Permit Book. and retained by. The duplicate must be retained by the APC. Physically identify to the CP in charge of the work. after reading and confirming its contents are understood. The location at which each operation is to be performed. (5). A diagram showing the points at which the equipment will be isolated and earthed.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
m. Draw the attention of the CP to any special instructions or safety measures noted on the Permit. the equipment on which the work or test is to be undertaken.
f. The reason for the operation. the CP throughout the work process. The keys of the equipment and safety locks are to be placed in a LOB by the AP The LOB . the original of which he has retained. (3). (2). who must retain the copy and issue the keys in accordance with Rule 3. (6). l.
The Permit must be signed by the AP initiating the work. The person issuing the LOA should inform the APC of any fire protection or security system inhibits he has initiated. n. Any other person or persons required to assist in the performance of the work are to do so only when the AP or the CP in charge is present. sanctioned by the APC and issued to the CP in charge of the work who.7
. after reading and confirming that he understands its contents. Show the CP the specific points of isolation and earthing. (7). c. The equipment concerned and the purpose of the work. Once the equipment is made safe to work upon. (The Permit Book shall be kept in close custody by the APC). (3).
j. (2). (4). (4).
(2). a new PFW or PFT must be issued. then the keys for the first LOB must be locked in the LOB for the second Permit. a. the cancellation section of the PFT should contain a declaration by the AP that all the CME have been reapplied to allow the PFW reissue.
p. the following procedure applies: (1). the AP is to return all keys immediately to the APC. d.
E. except when the LOA requires to be sanctioned. the AP relinquishing control and the AP accepting responsibility.(1) and the change authorised by the AP on both copies.
E11. the CP in charge of the work is to return the Permit to the AP for cancellation and sign the clearance portion of the duplicate.8
. of the equipment as may have been agreed. clearing the MV key register.
Transfer of responsibility for LOA is not to be authorised and any change of AP or CP should require the cancellation of original and re issue of a new LOA. In situations where two Working Parties. b. The acceptance of a Permit or LOA makes the CP personally responsible for directly supervising or undertaking the defined work or test. When more than one Working Party is concerned. Before cancellation of the Permit for completed work.
b.4. or availability for service. returned to an AP and cancelled.
e. Transfer of Control If it is necessary for the control of work to be transferred before the work is completed. q.3. Before suspended work is resumed. c. b.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
o. a. The person issuing the LOA is to retain the duplicate and inform the APC of the LOA details for record purposes. when the APC should retain the duplicate. Procedure for Clearance and Cancellation When work on equipment for which a PFW or PFT has been issued is suspended or completed. each having separate Permits are made safe by the same equipment keys. as in Rule E11. E11. When transferring control of AP both copies of the PFW or PFT are to be signed by . The CP must not leave the working place or undertake other work or tests while the defined work or test is in progress. When transferring control of CP both copies of the PFW or PFT should be changed . the AP is to check that the work or test has been completed and that the equipment is safe. . When cancelling a PFT to allow a PFW to be raised. The keys from the second LOB must be issued as Rule (j) above.4. and inform him of the return to. Upon cancellation of the Permit for completed work. During any temporary absence of the CP the work or test is to be suspended and . The cancellation of the Permit will be signed by the AP and noted by the APC. a Permit (or LOA) is to be issued to the CP in charge of each Working Party. adequate safety precautions taken until the work or test is resumed. The APC should note the transfer on both copies of the PFW or PFT and time and date the change. Precautions During Progress of Work The equipment isolated and earthed for work under the terms of a PFW or PFT is to remain so until the Permit has been cleared.
wiring or relays except by an AP or a CP acting under his direct supervision. (This rule does not exclude the use of approved voltage indicators.ON COMPLETION OF WORK a. is to re attach. (This is to include busbar Voltage Transformers (VT) when fitted). a new LOA is to be issued. all remote control and automatic features must first be rendered inoperative. On completion of the testing and after the final discharge. all temporary test conductors must be removed and the PFT cancelled. the AP is to ensure that all such Permits have been cancelled before the circuit main earths are removed.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
f. RULE 13 . or cause to be proved.
E13. Test connections must not be applied in a cell or compartment in which there is exposed metal live at medium voltage. or cause to be re attached. Whilst such work is in progress. the correct phasing of the equipment. air compressors. tap changing gear.
b. is to return to service any fire protection or security system. or approved devices for testing and phasing out circuits). The AP is to witness the withdrawal of all tools and workmen and must immediately supervise the restoration of the equipment to service as agreed by the APC. the AP must adjust. All cables including temporary test conductors are to be discharged before and after application of the test voltages. On completion of any alteration or repair. The section of the busbars on which work is to be carried out are to be isolated from all points of supply from which it can be made live. RULE 12 . prior to connection of MV equipment to the MV system. is to remove. All temporary conductors used for testing purposes are to be of an adequate size and easily visible. the AP responsible for applying the test voltage is to ensure that such equipment is adequately guarded to prevent danger. isolators.
E15.WORK ON MEDIUM VOLTAGE METAL CLAD SWITCHGEAR E15. no work is to be carried out on the controlling equipment. A PFT must be raised for the testing.
E12. Before work is carried out on remotely or automatically controlled equipment such as circuit breakers. a.
E14. When any MV equipment is to be subject to test voltage before being connected to the MV system. The APC must be informed of the cancellation and any issued keys returned immediately. is to prove.
d. all temporary earth connections.
b. RULE 15 . RULE 14 . When the work for which a LOA has been issued is suspended or completed the recipient is to return his copy of the LOA to the issuing authority for cancellation and sign the clearance portion of the duplicate. Before suspended work is resumed. and that danger notices are attached in conspicuous positions during the period the equipment may be subject to voltage. all permanent earth wires or leads.TESTING MEDIUM VOLTAGE EQUIPMENT a. or diesel generators. Busbar Spouts or Multi Panel Switchboard When work is to be carried out on busbar spouts the following operations are to be carried out in strict sequence: (1). When more than one PFW has been issued for work on MV equipment associated with the same CME. or cause to be removed.1.
b.REMOTELY AND AUTOMATICALLY CONTROLLED EQUIPMENT a.9
. All cables are to be discharged before connecting the temporary test conductors. or cause to be adjusted to a safety limit the setting of any protective gear relating to the MV equipment.
Where on load busbar isolators are installed. The insertion of the hand or any tool into the contact spouts is forbidden. Notwithstanding that work may only be required on one phase spout. The busbars are to be checked by means of an approved voltage indicator to verify that they are not live. Caution Notices must be attached at all points where the circuit can be made live. Work on spouts must then be done under the immediate supervision of an AP Removal . The spouts must only be worked on one at a time and that phase's earth replaced prior to working on the next phase.
Feed Spouts Voltage Transformer Spouts and Single Panel Busbar Spouts The spouts on which the work is to be carried out are to be isolated from all points of supply from which they can be made live. For the purpose of earthing metal clad switchgear.
h. and it is impossible to isolate them from all points of supply. the indicator itself being tested before and after such verification.
(4). The insertion of the hand or any tool into contact spouts for this purpose is forbidden. i. The spout contacts are to be checked by means of an approved voltage indicator to verify that they are not live. d.
E15. then whilst this work is in progress. only approved appliances shall be used.2.
E. before it is worked on. The circuit must be earthed with approved earthing equipment at the point of work and where practicable at all points of isolation of the supply. The checking with the voltage indicator is to be done on the panel which is to be earthed with the CME. b. (7). (6). on the isolated section of busbars.10
. The isolating arrangements are to be locked so that they cannot be operated and the shutters of live spouts shall be locked shut. a. CME of approved type is to be applied at a panel other than that at which work is to be done. Work on the spouts must then be done under the immediate supervision of an AP who is to prove each spout dead by means of an approved voltage indicator before it is worked on. of earths at the point of work and proof that each spout is dead will be done by means of an approved voltage indicator. no other work shall be carried out on the circuit connected to these spouts.
(3). all phases are to be earthed prior to commencement of work. If the only earths that can be applied to the circuit are those applied to the spouts and are the CME. Caution Notices must be attached at all points where the busbars can be made live. f. g. A PFW is to be issued. the indicator itself being tested before and after each verification. the indicator itself being tested immediately before and after verification. c. additional earths shall be efficiently connected at the nearest point to the point of work where access to the conductors can safely be obtained. Where the spouts are connected to an overhead circuit on which there is a likelihood of dangerous induced voltages.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
(5). Danger Notices must be attached (if applicable) on or adjacent to the live equipment at the limits of the zone in which work may be carried out. The isolating arrangements are to be locked so that they cannot be operated and shutters for live spouts are to be locked shut. then all switches that can be closed onto the busbars on which work is to be carried out are to have their mechanisms locked in the `open' position and the closing mechanisms must be made inoperative. A PFW must be issued. the indicator itself being tested before and after each verification. (8).
voltage transformer relay. the following operations are to be carried out in strict sequence: (1). the output circuit breaker or switchfuse is to be isolated and any output fuses removed. Caution Notices must be attached at all points of isolation. the switches are to be isolated and additionally the fuses are to be removed.11
Auxiliary Equipment When work is to be carried out on auxiliary equipment such as a circuit breaker truck. a. Additionally. The equipment is to be disconnected from all supplies and locked off from live conductors with safety locks. To prevent feedback from the output side of the transformer. The circuit breaker supplying the transformer is to be isolated. The earthing is to be achieved with approved earthing equipment. For transformers supplied from a switchfuse. CME is to also be applied preferably at the transformer side of the output circuit breaker or switchfuse. CME is to be applied preferably at the circuit breaker or switchfuse supplying the transformer. the voltage and auxiliary transformers isolated. Caution Notices must be attached at all points where the transformer can be made live. (4).
(5). When withdrawable equipment has been disconnected from all supplies and withdrawn from its normal live position. (3). If work on the withdrawn equipment carried out within a substation includes testing and adjustments. a LOA must be used. (4). When working on the connections to. a. Where remote tap changing facilities are part of the equipment. control or other equipment associated with live MV metal clad switchgear and there is a need to specify restriction of the access to be granted. or the windings of a transformer.
(2). its conductors shall be discharged to earth.4.
E. The conductors of the equipment is to be discharged to earth. (2).WORK ON MEDIUM VOLTAGE DISTRIBUTION TRANSFORMERS a. RULE 16 . (7). the remote control must be made inoperative.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
j. the auxiliary supplies required may be connected by the CP in charge of the work. the following operations are to be carried out: (1).3. The earthing is to be achieved with approved earthing equipment. Danger Notices must be attached where applicable on or adjacent to live equipment at the limits of the zone in which the work may be carried out.
(6). Withdrawable Equipment When work is to be carried out on withdrawable equipment. but need not remain connected to earth. all fuses or links associated with voltage and auxiliary transformers must be withdrawn and where practicable. (3). (5).
If the work is such that these clearances are not sufficient to avoid danger.6 kV but not exceeding 11 kV Exceeding 11 kV but not exceeding 22 kV Clearance 2.
Auxiliary Equipment Where work is to be carried out on auxiliary equipment associated with a live MV transformer and there is a need to specify restriction of the access to be granted. b. a.57 m 2. RULE 17 . This requirement does not apply to the disconnection of solidly earthed neutrals or to neutral equipment connected solely to the transformer on which work is to be done.64 m
NOTE Further guidance to the minimum clearance from an exposed live conductor can be obtained from BS 5486. or platform.
(9). unless the whole equipment is dead. The placement of the ropes or barriers is to be under the immediate supervision of the AP initiating the work.
c. a LOA is to be issued.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
(8). Danger notices must be attached to adjoining live MV equipment. f. the minimum clearances already quoted must also be obtained from the nearest exposed live MV conductor to the points from which work is carried out. other suitable arrangements are to be made to provide the requisite degree of safety.WORK IN MEDIUM VOLTAGE COMPARTMENTS CONTAINING EXPOSED LIVE MEDIUM VOLTAGE CONDUCTORS E17. the section which is made dead for work to be carried out is to be defined.12
E. At the time of issue of the PFW. Prior to issue of a PFW. the AP is to identify to the CP the transformer on which work is to be performed and that the transformer is de energised.
d. This is particularly relevant at locations with groups of transformers. If work cannot be carried out without leaving ground level or fixed platform or access ways. by the use of barriers or roping arranged so that the minimum clearance from the nearest exposed conductor to ground level. a.1. Danger Notices must be attached (where applicable) on or adjacent to the live apparatus at the limits of the zone in which work may be carried out.59 m 2. No person is permitted to climb over or under any rope or barrier. or access way which may be required to be used when the conductor is live is to be: Rated Voltage Not exceeding 6.1.
e.6 kV Exceeding 6. ropes and barriers are only to be re located or removed with the personal sanction and under the immediate supervision of an AP . the transformer is to be isolated from all common neutral earthing equipment from which it may become `live'. Safety Clearance to Live Conductors When work is to be carried out in MV compartments in which there are exposed live MV conductors then. The ropes or barriers are to be clearly visible and their meaning understood. Ropes or barriers must be so arranged that there is a properly defined access way into the area in which it is safety to work. The ropes or barriers must not be supported by any structure carrying electrical equipment or conductors.
E17. and must not carry any notice.
E16. as far as possible.
Use of Portable Ladders and Long Objects Where There are Exposed Live Conductors Portable ladders are to be of an approved type and of no greater length than is required for the work involved. Precautions taken to render the automatic control inoperative is to be noted on any Permit to Work. RULE 18 .
Operating Adjustments Operating adjustments on equipment operated by or containing compressed air which require the normal air supply.
(3). a. Long objects include any items of any material which may dangerously reduce safety clearances when used or moved. A Caution Notice must be attached.
E18. The crane or other equipment are to be connected to the MV compartment earthing system as soon as practicable. Automatic Control Before work or inspections are carried out in any enclosure protected by automatic fire extinguishing equipment: (1).1. are to be carried out only under the immediate supervision of an AP . Portable ladders and other long objects must not be used without the permission of the AP who is to define on site the conditions of use to the person in charge of the work. The actions to render the automatic control inoperative and to restore to service is to be carried out by an AP or a CP only. The automatic control is to be rendered inoperative and the equipment inhibited from operation or left on hand control. a.
E19. The limits of operation of such equipment is to be defined by the AP initiating the work and thereafter the equipment is to be erected or moved only within these limits and under his direct supervision. E18. When lifting or other equipment such as preformed scaffolding is taken into or out of a MV compartment.
c. The operation of the valves is to be prohibited by the application of rip out and tag out procedures.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
E17. The movement and erection of such ladders is to then be carried out only under the direct supervision of the person in charge of the work. and must be padlocked to a secure anchorage. a. portable ladders must not be left within MV compartments or switching stations. RULE 20 .
(2).2.WORK ON ANCILLARY EQUIPMENT E18. other than operating adjustments may be carried out on the MV equipment operated by or containing compressed air: (1).
(2). the route to be followed is to be agreed by the AP initiating the work.1. The valves controlling the supply of air to the equipment are to be closed and the air released from the associated receivers and pipework which are to be left open to atmosphere.2. When not in use.13
b. This is equally applicable to a LOA to such a protected enclosure. or other written instruction issued for the work in the protected enclosure.FIRE PROTECTION EQUIPMENT E19. The automatic control is to be restored immediately after the persons engaged on the work or inspections have withdrawn from the protected enclosure. a. Equipment Operated by or Containing Compressed Air The following precautions are to be taken before any work.
(4). d.
the actions to be taken are to be specifically defined permission is to be obtained from a AE. Portable Extinguishers Only approved portable extinguishers are to be used in the vicinity of live electrical equipment provided that in the handling of the extinguishers safety clearances are maintained. earthed with a cable of not less than 70 mm2 cross section. the AP is to inform the APC of his action. E19. RULE 21 .14
. When exceptionally it is necessary. d. NOTES: 1. 2. a.4.
c. notices to that effect are to be displayed adjacent to the fire protection equipment. The cable at the point of work must then be spiked in an approved manner. the space is to be thoroughly ventilated before entry.
E20.3. The steel spike should be of a remotely operated power type. Before issuing a PFW for work on a high voltage cable. The APC is to be informed at the time the actions take place and these actions must be recorded.
Equipment-Chemical Hazard Contact with chemicals used in fire protection equipment may be dangerous and in such cases.
When work is to be carried out on any cables which may be subjected to induced voltages from other live circuits in their proximity. General After discharge of portable or fixed fire extinguishers in an enclosed space. unless the conductors are dead and earthed. or breathing apparatus shall be worn if entry is necessary before the gases have cleared and the enclosed space declared to be safe. This process should not normally be carried out at sea.2. On completion. the AP in addition to the procedure of Rule E9. Direct discharge onto electrical equipment is prohibited unless the equipment is known to be disconnected from all sources of supply. and the APC is to give permission for the commencement of the movement. E19.WORK ON MEDIUM VOLTAGE CABLES a. The physical movement of MV cables whilst energised should be avoided. No person is to remove the outer protective sheathing on MV cables so as to expose the insulation which covers or supports any conductor subject to high voltage. special precautions are to be taken to prevent danger from any voltage which might appear. Prior to the spiking action and immediately after the action. is to identify the cable to be worked upon. E19.
b. the AP immediately supervising the movement is to inform the APC. a. a.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
(1). Authorising the issue of any deviation from the approved safety rules. All AP are to be issued with a card of authorisation. Authorised Person Medium Voltage a. Additional Earth a. Additional earths are to be applied on the instructions of the APC. The interpretation of the electrical safety rules and statutory requirements. following the issue of a PFW. An earth of approved type is to be applied during the work in hand. (2). Bus Section Switch a. The APC will normally be the Engineering Officer of the Watch (EOW) who is in charge of the main control room and associated switchboard. operation and maintenance of MV distribution systems.
F. These are normally persons of the rank of Chief Petty Officer and above. F1. and are fully understood by all AP and other persons concerned. these being: (1). prior to leaving the control room. Where the EOW is required away from the control room he must formally transfer his authority to a person qualified to discharge these duties. See Table F1 for general duties. The selection. `Approved' means of a type complying with Statutory Regulations.
F2. See Table F1 for general duties.
F3. Ensuring that all amendments to the approval safety rules are brought to the attention of. British Standards and sanctioned for use by the Authorising Engineer or the APC on his behalf. NES. The Marine Engineering Officer (MEO) shall normally discharge the duties of the AE. Authorising Engineer a. (3).
F5. F6. A switch connecting two sections of a common busbar. Card of Authorisation a. He is responsible for the overall co ordination of the operation and maintenance of all electrical distribution systems.
F4. Approved a. Authorised Person in Control a.1
. when he is instructed in writing to do so. they are fully acquainted with the electrical safety rules and any authorised variations or agreed local versions and with all applicable Statutory Regulations and Naval Requirements. A member of Ship's Staff who meets the requirements of a CP and is appointed or selected by the AE to carry out specific tasks in connection with the control.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
F7. who are over 21 years of age and have formally demonstrated that. to control distributions and fault levels.
See Table F1 for general duties. (4). they are fully conversant with ship's electrical distribution system and equipment. training and appointment of AP. Normally of Officer or Senior Rate status. SAFETY TERMINOLOGY
This Annex provides a list of general terminology and related actions to be taken to ensure safety of personnel.
c. b. they are technically competent to safely operate and make safe to work on or test the systems and equipment with which they are concerned.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
(3). they have satisfactorily completed all appropriate training courses including first aid treatment of electric shock. A register will be kept of Authorisation. renewal and cancellation of all Cards of Competent Person II (CP II) p p p p Competent Person III (CP III) p p
Authorised Authorised Competent Person in Person Person I Control (AP) (CP I) (APC) p p p p p p p p p p
Enter MV Compartments Receive Limitation of Access (LOA) Routine Switching MV Work: Receive Permit for Work (PFW). Authorising Engineer (AE) the issue.
All AP will surrender for renewal and revalidation their Card of Authorisation once a year or on leaving the post which required them to be authorised.2
. (4). Issue and Cancel PFW Overall Control of MV System Resolve Operational disagreements between APS and assume control as APC if required
Table F1 – Responsibilities for Medium Voltage Related Activities ANNEX F F. Permit for Test (PFT) Issue/Cancel LOA MV Switching Isolating and Earthing Apply/Remove MV (Circuit Main Earth (CME) Receive.
(2). Members of Ship's Staff and/or contractors personnel who are competent to carry out. have adequate knowledge of the electrical safety rules and any authorised variations or agreed local versions and with all applicable Statutory Regulations and Naval Requirements.
F11. (3). Competent a. a. b.
F9. and carry out work on or near MV equipment safely. A register will be kept of the issue. calling attention to the danger of approaching or interfering with. Assessed and certified by the AE as having the technical knowledge and/or experience adequate to prevent danger and/or injury.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
F8. An earth normally applied by locking the main breaker. Caution Notice a. are familiar with installations and equipment upon which they are required to work. receive a PFT/PFW or LOA.
F13. under the supervision of an AP specific tasks in connection with the electrical system .
(3). and equipment. renewal and cancellation of all certificates.MEN WORKING' in a black on an orange/yellow background (as defined in BS 2929). receive a LOA. conveying a warning against interference with the apparatus. (4). A notice of approved form attached to apparatus or its control equipment. Grade I A person assessed and certified as competent to enter an MV compartment. in either the circuit or busbar earth position integral to the breaker. receive a LOA and carry out work near MV equipment safely. Grade II A person assessed and certified as competent to enter an MV compartment. The notice carries the words `DANGER . c. The AE will issue certificates of competency only to persons over 18 years of age who can formally demonstrate that they. Grade III A person assessed and certified as competent to enter an MV compartment. The notice carries the word `CAUTION . Danger Notice a. The application of a circuit main earth is to be carried out before a PFW is issued on the instruction of the APC. have adequate technical knowledge and experience to avoid danger presented by the work to be undertaken. perform routine switching and carry out work near MV equipment safely. Competent Person a.3
. Certificate of Competency a. have satisfactorily completed all appropriate training courses including the first aid treatment of electric shock. A notice in approved form attached to apparatus or its control equipment when live. such apparatus. Circuit Main Earth
F12.LIVE EQUIPMENT' with the words in red on a white background (as defined in BS 2929). The three grades of CP are: (1).
All certificates of competency are to be reviewed at least once every three years and are to be surrendered when leaving the post which required the certificate to be issued.
(2). (1).
F14. the removal and secure placement of fuses. Key Press a. for the secure retention of the keys of all safety locks in use for a particular task. after being disconnected from any live system and discharged.
F21. Live means connected to a source of electrical energy or otherwise electrically charged.
F16. Equipment is isolated when it is disconnected and separated from every source of electrical energy in such a way that this disconnection and separation is secure. Limitation of Access a.4
. The LOA is to be signed by an AP An example on the format of the LOA is given at . A MV safety programme specifies the agreed sequence of operation and any special safety measures necessary to make MV equipment safe for work or test prior to the issue of a PFW or PFT. and locking in.
(2). and locking in. in the case of withdrawable switchgear. Figure F2. Key Safe a.
F20. links or jumper connections. the operation of controlling switchgear to. An example on the format of the MV Switching Programme is given at Figure F1. The opening only (Switching OFF) of switchgear by any person to prevent damage or danger to life or plant. an immediate discharge of electrical energy without danger.
F18. A key safe is a locked cupboard for the secure retention of safety locks and `in use' portable Lock Out Boxes (LOB). F19.
F23. the `Isolated' position. either portable or fixed. A LOB is an approved device. Earthed a. The programme is to be signed by an AP and be countersigned by the APC. Equipment is dead when it is at or about zero potential with respect to the ship's structure. Isolated a.
A key press is a locked keyboard for the secure retention and display of the keys of all MV equipment. Lock Out Box a. Medium Voltage Safety Programme a. Dead a. An LOA is to be issued when a PFW is not applicable but verbal instruction is not considered sufficient. by moving the controlling switchgear from the `service' position to. Isolation may be achieved by.
F15. Connected by a suitable means to the main body or structure of the ship in such a manner as will ensure at all times. A LOA defines the limits and specifies the work to be performed in the vicinity of live equipment and any special instructions or safety measures required. Live a. (1). Emergency Switching a. the OFF position or.
F25. isolated from all live conductors.
F26. Permit for Work on Medium Voltage Equipment a. (1).5 ANNEX F
. An example on the format of the PFW is given at Figure F4. (3).INT DEF STAN 02–607 / ISSUE 1 (NES 607)
F24. The PFT is issued to make known to the CP exactly which equipment is. has been discharged. Permit for Test on Medium Voltage Equipment a. Potential Detector a.
F29. connected to earth and made safe to test. (4). F28. A potential detector is an approved instrument for proving that an isolated MV circuit is dead. (2). THESE ARE TO BE OPERATED ONLY WITH THE SPECIFIC PERMISSION OF THE AUTHORISED PERSON IN CONTROL. is connected to earth and safe to work on. An example on the format of the PFT is given at Figure F3. (4). The permit is to be signed by an AP and countersigned by the APC. Main Control Room a. Routine Switching
ROUTINE SWITCHING DOES NOT COVER THE OPERATION OF BUS-SECTION SWITCHES. dead. A PFW specifies the work to be carried out on any MV equipment and is issued to the CP in charge of that work. isolated from all live conductors. A PFT specifies the tests to be carried out on any MV equipment and is given to the CP in charge of these tests. A system of mechanical interlocks such as castell keys or fortress keys designed to inhibit the simultaneous operation of two or more breakers. (1). F.
The PFT will also detail which earths will be removed during the tests and any special instructions or safety measures. (3). discharged. The permit shall be signed by an AP and countersigned by the APC. Main Control Room is a generic term identifying the room from which the electrical distribution system is controlled and where the APC is normally on duty. (2). The PFW is issued for the purpose of making known to the CP exactly which equipment is.
The PFW will also detail any special instructions or safety measures. Permissive Interlocks a. The detector shall be tested immediately before and after use. F27. dead.
Each safety lock will have only one key which is to be tallied and kept in the LOB applicable to the PFW or PFT under which it has been applied.
b. c. see Annex E. rotary convertors. Direct Supervision . Supervision a. Working Party a. b.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
F32. and his concurrence sought prior to the switching operation.
F.requires an AP or a CP to be visible or within hailing distance at all times during the progress of the work. The normal switching in or out of circuit.requires an AP or a CP to be standing immediately beside the Person(s) performing the work. to meet increasing or decreasing load demands. Switching a.
F30. Indirect Supervision . Routine switching will generally be that carried out on a regular/daily basis. earthing or other safety devices. Safety Locks a. b. Where switching of major loads is required outwith recognised daily practice. A working party is the person or persons working under the supervision of an AP or a CP and may include the AP or CP working by himself. of such equipment as motor generators. fuses or other methods of making or breaking a circuit and thereby connecting or disconnecting an electrical source. etc.
F31. Switching is the operation of switchgear.
F33. Routine switching operations are to be carried out only by an AP or CP .6
. Immediate Supervision .may be achieved by the use of a high integrity communication system between the AP or CP and the person performing the work. For Safety Rules on or near Medium Voltage equipment. the APC is to be notified. These are padlocks used to lock off any means of isolation.
Figure F1 – Medium Voltage Switching F.7 ANNEX F
Figure F2 – Limitation of Access ANNEX F F.
ON MEDIUM VOLTAGE EQUIPMENT
Figure F3 – Permit for Test F.9 ANNEX F
Figure F4 – Permit for Work ANNEX F F.10
Cables: 1. 4.7. F.5 Clearance: 4. 4.2.11. F.4 FEP .3. 4.4 Low Voltage: 3.8.1.1 System: 1.14 Capacitance: 1. rating: 1.2 Control: 3.2 Authorising Engineer: F. 4.5.8.5. 3. 4.2.2 Constraints Hardware: 1.14 High Voltage: 2.12.7.3.1
Fault: 1.3. 3. 3.see propulsion: 4. 4. E.4 Automatic Voltage Regulator: 3.3 Fire Risk: 3.1.8 Fuse: 3.11.1. 3.INT DEF STAN 02–607 / ISSUE 1 (NES 607)
ALPHABETICAL INDEX (NOTE: Page numbers are given)
Authorised Person in Control: E.7. 3. F.4. F. 3. 3.5 Earthing: E. F.3 Generator: 3.5 Limited Fire Hazard: E.1.2.1.2. 3.1 Output Voltage: 3. 3.1 Short Circuit: 3. E. F. 1.2 Availability: 4. F.1.8. F. 4.1 Symmetrical: 3. 3. E. E.2.1.2 Creepage: 3.13 Parallel Operation: 4.11 Busbar: 1. current: 4.4
Bulkhead Penetrators: 3. E.6 High Impedance Neutral: 3.1.6.14.1. D.12. F. E.8.8 Availability and Reliability: 4.12. 4. E. 3. 1. F. F. 3.1 Asymmetrical: F.10.6 Maintenance: 3. 2.11. F.6 Current. 4.2 Energy Storage: 4.13 Circuit Breaker: 1.1 Rating: F.7.4 Start And Stop: 4. 4.4.3 Low Impedance: 3.8.4
Generator: 1.2 Earthing: F.1.3.6 Unearthed Neutral: 3.6 Minimum Operation: 4.2 Conversion equipment: 4. F. F. E.7.12 Competent Person: 4.6.1 Earth Fault: 3.4.1 Fault.4 Single Operation: 4. 3.7 High Impedance: 3. F.12.9.8.7. 3.2
.1 Level: 1.3 Earth Leakage Currents: D.3 Distortion: D. E. F.2 Authorised Person: 2.6 Configuration: 4. F.7. F. D. F.2
Discrimination: 3. E.4. 4. 3.4.5.3. 4.3 Earth Fault: 3.8.6.3 Solid: 3.4. F.3.1.4. F.1.9. 4.6 Electromagnetic Compatibility: 1.5. 1. 1.1 Current: 1.6 User: 1.8
Earth: 3.9.1.3 Additional Earth: F.4.
Harmonics: 1.3, 1.5
Notches: 1.4, 1.5; D.2 Notice: 2.4; E.13 Caution Notice: 2.4; E.13 Danger Notice: 2.4; E.13
I2R losses: 1.5 IEE Regulations: 1.1, 1.2 Inductance : 1.5, 1.7 Inductive: 4.8 Instrumentation: 4.3 Insulation: 1.4, 1.5; 2.1; 3.10, 3.12, 3.13; 4.12 System: 3.12 Integrity: 3.3; 4.4; F.6 Interlock: F.5 Inverse Time Over-Current relay: 3.4
Oil Filled Components: 3.12
Padlock: 2.3 Panel: 2.1; 4.2; E.9, E.10 Panel Electronic Circuit (PEC): 2.1 Peak: 3.13 Permit for Test (PFT): F.2 Permit for Work (PFW): E.14; F.2 Point of Common Coupling: 1.2; 4.5 Prime Movers: 4.2; 4.4 Propulsion: 1.1, 1.2; 3.1; 4.1 Cruise: 4.3 Full Electric: 1.1 Integrated Full Electric: 1.2; 4.3 System: 1.2; 3.2 Vessel Speed: 4.5 Protection: 3.11; 4.1; E.1, E.13, E.14 Fire: E.7, E.9 Protection, Circuit: 3.5 Pulsed Loads: 3.1; 4.4; D.2
Key Safe: F.4
Lightning: 1.3; 4.7 Limitation of Access (LOA): F.2 Lloyd's Register of Shipping: 2.2 Lloyd's Regulations: 1.1, 1.2 Load chart : 3.1 Lock-out box : E.7
Metallic screens: 4.1 Modulation: 1.6; D.1 Motor: 1.1, 1.4; 3.12; F.6 Electric Propulsion: 1.1 Supply Cable: 3.4 Motor Thermal Protection Unit: 3.5 Quality: 1.2
Rated current: 1.7 Relay: 3.5 Reliability: D.3 rms: 1.1; 3.12 Routine Tests: 3.13
Switchboard: 3.12; 4.1 Switchgear: 3.8, 3.12; 4.3
Safety: 2.3, 2.4; 3.10; 4.2 Sags: 1.4; D.1 Sensing Circuits: 4.3 Separation: 4.1 Ships Services System: 1.1 Shore Supplies: 3.13; 4.1 Short Circuit: 3.6; D.2 Spikes: 1.4; D.1 Split Generation: 1.1; 4.2; 4.4 Statement of Technical Requirements : 4.5 Supplies, alternative: 4.7 Surges: 1.4; 3.7, 3.13
Total Harmonic Distortion: 1.8 Transformers: 1.2, 1.3; 3.4, 3.12, 3.13; 4.3 Transient: 3.1 Trunking: 4.1 Type Tests: 3.12
Vacuum: 3.12 Voltage drops: 1.1
Information on all Defence Standards is contained in Def Stan 00-00 Standards for Defence Part 3 .mod.
.© Crown Copyright 2001 Copying Only as Agreed with DStan
Defence Standards are Published by and Obtainable from: Defence Procurement Agency An Executive Agency of The Ministry of Defence Directorate of Standardization Kentigern House 65 Brown Street GLASGOW G2 8EX
DStan Helpdesk Tel 0141 224 2531/2 Fax 0141 224 2503 Internet e-mail enquiries@dstan. Compliance with a Defence Standard does not in itself confer immunity from legal obligations. Revision of Defence Standards Defence Standards are revised as necessary by up issue or amendment.uk
File Reference The DStan file reference relating to work on this standard is D/DStan/069/02/607 Contract Requirements When Defence Standards are incorporated into contracts users are responsible for their correct application and for complying with contractual and statutory requirements. when making use of a Defence Standard encounters an inaccuracy or ambiguity is requested to notify the Directorate of Standardization (DStan) without delay in order that the matter may be investigated and appropriate action taken. Any person who. Index of Standards for Defence Procurement Section 4 ‘Index of Defence Standards and Defence Specifications’ published annually and supplemented regularly by Standards in Defence News (SID News). It is important that users of Defence Standards should ascertain that they are in possession of the latest issue or amendment.
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