NYSRC 

RELIABILITY 

RULES

For Planning

And Operating

the New York State

Power System

Version 29

January 7, 2011
NYSRC RELIABILITY RULES

For Planning and Operating

the New York State Power System

Version 29

January 7, 2011

New York State Reliability Council, L.L.C.

Initially Adopted : September 10, 1999
NYSRC Reliability Rules

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NYSRC RELIABILITY RULES 

Table of Contents

I. INTRODUCTION............................................................................................... 4

II. NYSRC RELIABILITY RULES ....................................................................... 12

A. RESOURCE ADEQUACY..........................................................................13

A-R1. NYCA Installed Reserve Margin Requirement .................................13

A-R2. Load Serving Entity Installed Capacity Requirements.......................14

A-R3. External Installed Capacity ...............................................................14

B. TRANSMISSION CAPABILITY - PLANNING .........................................16

B-R1. Thermal Assessment.........................................................................19

B-R2. Voltage Assessment..........................................................................20

B-R3. Stability Assessment.........................................................................21

B-R4. Extreme Contingency Assessment ....................................................22

B-R5. Restoration .......................................................................................23

B-R6. List of NYS Bulk Power System Facilities .......................................23

B-R7. Fault Current Assessment .................................................................23

C. RESOURCE, System & DEMAND DATA REQUIREMENTS...................26

C-R1. Verification Testing of Resource Capacity........................................26

C-R2. Generating Unit Availability.............................................................26

C-R3. Load Forecasting ..............................................................................27

C-R4. System Data Requirements...............................................................27

C-R5. Disturbance Recording .....................................................................27

D. OPERATING RESERVES ..........................................................................33

D-R1. Operating Resource Adequacy..........................................................33

D-R2. Minimum Operating Reserve Requirement.......................................34

D-R3. Availability and Category.................................................................35

D-R4. Restoration of Ten (10) Minute Reserves..........................................36

E. TRANSMISSION CAPABILITY - OPERATING .......................................37

E-R1. Thermal Assessment.........................................................................39

E-R2. Voltage Assessment..........................................................................41

E-R3. Stability Assessment.........................................................................41

E-R4. Post-Contingency Operation.............................................................42

E-R5. Outage Coordination ........................................................................43

E-R6. Operation During Impending Severe Weather...................................44
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E-R7. Operation During a Severe Solar Magnetic Disturbance ...................44

E-R8. Fault Current Assessment .................................................................45

E-R9. Applications of the NYSRC Reliability Rules...................................45

E-R10.Exceptions to the NYSRC Reliability Rules .....................................45

F. OPERATION DURING MAJOR EMERGENCIES.....................................49

F-R1. Transmission Thermal Overloads .....................................................49

F-R2. Post-Contingency STE Rating Violations .........................................50

F-R3. High or Low Voltage........................................................................51

F-R4. Post-Contingency Voltage ................................................................52

F-R5. Operating Reserve Deficiency ..........................................................53

F-R6. Stability Limit Violation...................................................................53

F-R7. Low Frequency.................................................................................54

F-R8. Load Shedding Allocation ................................................................55

G. SYSTEM RESTORATION..........................................................................57

G-R1. NYCA System Restoration Plan .......................................................57

G-R2. System Restoration Training and Simulation Programs.....................57

H. SYSTEM PROTECTION ............................................................................64

H-R1. Bulk Power System Protection..........................................................64

H-R2. Bulk Power System Protection Maintenance.....................................64

I. LOCAL RELIABILITY RULES..................................................................66

I-R1. Operating Reserves/Unit Commitment (New York City) .................66

I-R2. Locational Reserves (New York City) ..............................................66

I-R3. Loss of Generator Gas Supply (New York City)...............................67

I-R4. Thunderstorm Watch (New York City).............................................67

I-R5. Loss of Generator Gas Supply (Long Island) ....................................67

J. NYISO CONTROL CENTER COMMUNICATIONS.................................70

J-R1. NYISO/Market Participant Communications....................................70

J-R2. NYISO Communications Under Emergency Conditions..................70

K. RELIABILITY ASSESSMENT...................................................................72

K-R1. NYISO Manuals.........................................................................73

K-R2. Reliability Assessments..............................................................73

K-R3. Extreme System Conditions Assessment.....................................73

III. NYSRC/NPCC/NERC RELIABILITY RULE CROSS-REFERENCE............... 78

IV. GLOSSARY...................................................................................................... 80
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A. GLOSSARY INDEX ................................................................................ 81

B. GLOSSARY ............................................................................................. 83

V. SYSTEM CONDITIONS FOR OPERATING STATES OF THE NYS BULK 

POWER SYSTEM............................................................................................. 92

VI. EXCEPTIONS TO RELIABILITY RULES....................................................... 95

VII. NYSRC PROCEDURE FOR NEW YORK CONTROL AREA TRANSMISSION 

REVIEWS ....................................................................................................... 103

VIII. RULE REVISION LOG .................................................................................. 107

TABLES:

Table A Design Criteria Contingencies.....................................................18

Table B Extreme Contingencies...............................................................18
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I. INTRODUCTION

1. Foreword

This document contains the New York State Reliability Council, L.L.C. *

(“NYSRC”) Reliability Rules for Planning and Operating the New York 

State Power System (“Reliability Rules”), and defines in terms of 

measurements, the required actions or system performance necessary to 

comply with the Reliability Rules. The New York Independent System 

Operator (“NYISO”) is required to comply with all of the Reliability 

Rules. To the extent that Market Participant action is necessary to 

implement a Reliability Rule, a requirement for such action is included in 

the NYISO procedures, which are binding on all Market Participants.

2. Background

The mission of the NYSRC is to promote and preserve the reliability of the

New York State Power System (“NYS Power System”) in the New York 

Control Area (“NYCA”). This mission includes developing, maintaining, 

and from time-to-time, updating the Reliability Rules which shall be 

complied with by the NYISO and Market Participants. The NYSRC fulfills 

this mission through its focus on maintaining the reliability of the New 

York State Bulk Power System (“NYS Bulk Power System”).

The NYSRC carries out its mission in accordance with the NYSRC and 

NYISO/NYSRC Agreements. These agreements establish the 

responsibilities, duties, and the obligations of the NYSRC.

The NYSRC’s mission also includes monitoring compliance by the NYISO 

with the Reliability Rules by working in consultation with the NYISO and

to assure compliance, including when necessary, seeking compliance 

through the dispute resolution procedure contained in the NYISO/NYSRC

 

*

 All terms in italics within this document are

 defined in the Glossary in Part IV.
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Agreement, and taking such other actions which may be necessary to carry 

out the purpose of the NYSRC Agreement.

The NYSRC carries out this mission with no intent to advantage or 

disadvantage any Market Participant’s commercial interest.

The NYSRC Executive Committee directs all NYSRC activities. The 

NYSRC Executive Committee is comprised of thirteen (13) members, 

currently consisting of one representative from each of the six 

Transmission Owners, one representative of the Wholesale Sellers, one 

representative of the Industrial and Large Commercial Consumers, one 

representative of the Municipal Electric Systems and Cooperatives, and 

four members with no affiliation with any Market Participant. Three 

subcommittees report to the NYSRC Executive Committee: The Reliability 

Rules Subcommittee develops and updates the Reliability Rules. The 

Reliability Compliance Monitoring Subcommittee monitors NYISO 

compliance with the Reliability Rules. The Installed Capacity 

Subcommittee oversees the development and analysis of studies related to 

the NYSRC’s adoption of the annual statewide installed capacity 

requirement (“ICR”) for the NYCA.

The Reliability Rules, the NYSRC Agreement, the NYISO/NYSRC

Agreement, and other NYSRC documents may be downloaded from the 

NYSRC web site, http://www.nysrc.org.

3. Reliability Rules Development

It is critical that the NYISO and all Market Participants be advised of 

proposed changes to the Reliability Rules and that they be permitted to 

participate in the revisions to the Reliability Rules. For this purpose, the 

NYSRC has established an open process through which comments and 

proposed Reliability Rule revisions from all Market Participants and the 

NYISO will be considered. This open process is described in NYSRC

Policy No. 1, “Procedure for Reviewing, Developing, Modifying, and 
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Disseminating NYSRC Reliability Rules.” This procedure gives the 

NYSRC the authority to develop or modify Reliability Rules on an 

expedited basis when conditions require such action.

The Reliability Rules define the reliability of the NYS Power System using 

the following two terms:

 Adequacy – The ability of the electric systems to supply the aggregate 

electrical demand and energy requirements of their customers at all 

times, taking into account scheduled and reasonably expected 

unscheduled outages of system elements.

 Security – The ability of the electric systems to withstand sudden 

disturbances such as electric short circuits or unanticipated loss of 

system elements.

4. What the Reliability Rules Include

The Reliability Rules, in accordance with the NYSRC and NYISO/NYSRC

Agreements, incorporate the following:

a. North American Electric Reliability Council (“NERC”)

Standards.

b. Northeast Power Coordinating Council (“NPCC”) Criteria, 

Guidelines and Procedures.

NPCC criteria may be more specific or stringent than NERC Standards 

and Policies, recognizing regional characteristics or reliability needs.

c. New York-Specific Reliability Rules.

New York-Specific Reliability Rules may be more specific or stringent 

than NERC Standards and NPCC Criteria, recognizing NYCA system 

characteristics or reliability needs.
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d. Local Reliability Rules.

Local reliability rules are more stringent than the general New YorkSpecific Reliability Rules and apply to certain NYCA zones, 

recognizing unique local area characteristics or reliability needs.

This document contains only the New York–Specific Reliability 

Rules and local reliability rules. NERC Standards and NPCC Criteria 

can be found at http://www.nerc.com and http://www.npcc.org, 

respectively.

Part III is a cross-reference of New York–Specific Reliability Rules 

with corresponding NPCC criteria and NERC Standards.

5. Maintaining the Reliability of the NYS Bulk Power System

The Reliability Rules in this document focus on that portion of the NYS 

Power System which constitutes the NYS Bulk Power System. Maintaining 

the reliability of the NYS Bulk Power System provides protection for the 

entire NYCA system from widespread and cascading outages. Therefore, 

the reliability of the NYS Power System is dependent on maintaining NYS 

Bulk Power System reliability through the Reliability Rules.

NPCC defines the bulk power system as “the interconnected electrical 

systems within northeastern North America comprising generation and 

transmission facilities on which faults or disturbances can have a 

significant adverse impact outside of the local area”. The NYS Bulk Power 

System is “the portion of the bulk power system within the NYCA, 

generally comprising generating units 300 MW and larger, and generally 

comprising transmission facilities 230 kV and above. However, smaller 

generating units and lower voltage transmission facilities on which faults 

and disturbances can have a significant adverse impact outside of the local 

area are also part of the NYS Bulk Power System”.
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The application of the NYS Bulk Power System definition in the NYCA is 

consistent with similar NPCC and NERC bulk power system definitions. 

The NYISO shall develop, maintain, and keep current a list of NYS Bulk 

Power System facilities in its annual NYISO “Load and Capacity Data 

Report”.

6. NYS Bulk Power System States

An objective of the Reliability Rules is to provide for the operation of the 

NYS Bulk Power System within the normal state. It is recognized, however, 

that certain system conditions may cause the system to depart from the 

normal state to four other operating states: Warning, Alert, Major

Emergency, and Restoration. These five operating states are defined in 

Part V. 

Examples of system conditions that could cause departure from the normal

state are: capacity deficiencies, energy deficiencies, loss of generation or 

transmission facilities, transmission facility overloads and high or low 

voltages, abnormal power system frequency, and environmental episodes. 

When the system enters an operating state other than the normal state, the 

primary objective of the NYISO shall be to return the system to the normal 

state as soon as possible by achieving the criteria set forth in Part V.

7. Format of Reliability Rule Sections

Part II contains eleven Reliability Rule groups or sections. The 

presentation of each Reliability Rule section is based on the following 

general format:

 Introduction – Background and general need for the Reliability 

Rules that are included in the Reliability Rule section.

 Reliability Rules – Explicitly stated technical and performance 

reliability outcomes that must be achieved. Reliability Rules are 
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shown in bold. There are currently two to eight Rules in each 

Reliability Rule section.

 Measurements – Specific requirements, including procedures, 

performance, and other actions that must be implemented by the 

NYISO in order to ensure compliance with the related Reliability 

Rule. Each Reliability Rule has one or more related Measurements. 

 Guidelines – NYISO guidelines or procedures that must be 

followed to comply with the Reliability Rules.

Part IV is a glossary of terms used in the Reliability Rules. Part VII 

is a log of initial adoption and revision dates for the Reliability

Rules and Measurements.

8. Compliance with the Reliability Rules

The NYS Bulk Power System involves multiple participants. Since all 

electric systems in the NYCA network are electrically connected, whatever 

one entity does can affect the reliability of other aspects of the NYCA.

Therefore, the Reliability Rules describe the actions that the NYISO and 

Market Participants must take in order to maintain the reliability of the 

NYS Bulk Power System. The NYISO is responsible for the implementation 

of all Reliability Rules. To the extent actions by Market Participants are 

necessary to implement the Reliability Rules, such requirements are set 

forth in NYISO procedures and enforced by the NYISO under its tariffs.

When the NYSRC Executive Committee adopts a Reliability Rule or 

Measurement, it becomes effective immediately. The NYISO and Market 

Participants are required to comply with the Rule or Measurement in 

accordance with an Implementation Plan. Section VII, Reliability Revision 

Log, provides the date on which each Rule and Measurement was adopted 

or modified by the Executive Committee.
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All NYISO policies, procedures, guidelines, and manuals must comply 

with the Reliability Rules. The NYISO must immediately notify the 

NYSRC if it finds that it is not in compliance with the Reliability Rules, 

regardless of whether the non-compliance is the result of the action or 

inaction of the NYISO or one or more Market Participants.

NYSRC Policy 4, “Procedure for Monitoring Compliance with the NYSRC 

Reliability Rules,” addresses how the NYSRC monitors the NYISO

compliance with the Reliability Rules.

9. Applications of the NYSRC Reliability Rules

The Applications of the Reliability Rules were operating procedures and 

local reliability rules prior to the formation of the NYISO. They consist of 

procedures that apply to very specific system locations or conditions. The 

Applications of the Reliability Rules are included on the NYISO Web site, 

http://nyiso.com.

Prior to the NYISO startup, the Applications of the Reliability Rules were 

implemented by the transmission owners. The implementation of the 

Applications to the Reliability Rules will continue to require 

close coordination between the transmission owners and the NYISO in 

order to protect the reliability of the NYS Power System. For example, the 

transmission owners must coordinate with the NYISO on the 

implementation of Applications of the Reliability Rules where the NYISO

lacks monitoring capabilities. The transmission owners also 

must coordinate with the NYISO on the implementation of the Reliability 

Rules for those portions of the New York State Transmission System 

("NYS Transmission System") not included in the NYISO secured 

transmission system. 

New Applications or modifications to existing Applications may be 

proposed by a transmission owner or the NYISO, and must be approved 
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by the NYISO. Upon approval, the new or modified Application must be

included on a list of Applications on the NYISO’s website. The NYISO 

also must advise the NYSRC of any new or modified Applications. The 

NYSRC Reliability Rules define actions by the NYISO for meeting these 

requirements.

 

10. Exceptions to the Reliability Rules

Requests to obtain exceptions to the Reliability Rules must be submitted 

to and approved by the NYSRC. The NYISO or any member of the 

Executive Committee may submit a request for an exception to the NYSRC

Executive Committee in accordance with NYSRC Policy No. 1. A list of 

specific exceptions to the Reliability Rules is included in Part VI.
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II.

NYSRC 

RELIABILITY 

RULES
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NYSRC Reliability Rules

A. RESOURCE ADEQUACY

Introduction

The NYSRC is responsible for establishing the annual statewide ICR in order to 

ensure adequate resource capacity. Among the factors to be considered in the 

calculation of the ICR are the characteristics of the loads, uncertainty in the load

forecast, outages and deratings of generating units, the effects of interconnections 

to other control areas, and transfer capabilities within the NYCA. The annual 

statewide ICR is established by implementing Reliability Rules for providing the 

corresponding statewide installed reserve margin ("IRM") requirement. The IRM 

requirement relates to ICR through the following equation:

ICR = (1+ IRM Requirement) x Forecasted NYCA Peak Load 

In order to meet the annual statewide ICR established by the NYSRC, the NYISO

establishes installed capacity (“ICAP”) requirements for the load serving entities 

(“LSEs”), including locational ICAP requirements, recognizing internal and 

external transmission constraints.

Reliability Rules

A-R1. NYCA Installed Reserve Margin Requirement

The NYSRC shall establish the IRM requirement for the NYCA

such that the probability (or risk) of disconnecting any firm load

due to resource deficiencies shall be, on average, not more than 

once in ten years. Compliance with this criterion shall be 

evaluated probabilistically, such that the loss of load expectation 

(LOLE) of disconnecting firm load due to resource deficiencies 
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A. RESOURCE ADEQUACY (CONT’D.)

shall be, on average, no more than 0.1 day per year. This 

evaluation shall make due allowance for demand uncertainty, 

scheduled outages and deratings, forced outages and deratings, 

assistance over interconnections with neighboring control areas, 

NYS Transmission System emergency transfer capability, and 

capacity and/or load relief from available operating procedures.

A-R2. Load Serving Entity Installed Capacity Requirements

LSEs shall be required to procure sufficient resource capacity for 

the entire NYISO defined obligation procurement period so as to 

meet the statewide IRM requirement determined from A-R1. 

Further, this LSE capacity obligation shall be distributed so as to 

meet locational ICAP requirements, considering the availability and 

capability of the NYS Transmission System to maintain A-R1 

reliability requirements.

A-R3. External Installed Capacity 

ICAP from resources external to the NYCA for satisfying a portion 

of LSE ICAP requirements must be demonstrated to be available 

and deliverable to the NYCA borders. ICAP from resources

external to the NYCA shall be permitted to the extent A-R1 

reliability requirements are satisfied.

Measurements

A-M1. The NYSRC shall periodically perform resource adequacy studies to 

update the required statewide IRM. A report shall be prepared
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A. RESOURCE ADEQUACY (CONT’D.)

providing the assumptions, procedures, and results of the study. (AR1)

A-M2. The NYISO shall prepare a report for the next capability period

showing (1) LSE IRM and ICAP requirements so as to meet the 

statewide IRM requirement, (2) LSE locational ICAP requirements for 

applicable NYCA zones, such as New York City and Long Island, and 

(3) the allowable amount of LSE ICAP requirements that may be 

located externally to the NYCA. The report shall include the 

procedures, factors, and assumptions utilized by the NYISO to 

determine these LSE ICAP requirements. The NYISO Installed 

Capacity Manual shall include procedures to establish LSE ICAP 

requirements. (A-R2, A-R3)

A-M3. Each LSE shall certify and maintain its ICAP obligation for the next 

capability period, including any locational and external ICAP, in 

accordance with LSE ICAP requirements established by the NYISO

Tariff and the NYISO Installed Capacity Manual. (A-R2, A-R3)

A-M4. The NYISO shall notify those LSEs that are determined to be deficient 

in meeting their ICAP requirements including locational ICAP 

requirements, for the next capability period. This notification shall 

specify appropriate deficiency charges. The NYSRC shall be 

immediately notified of such capacity deficiencies, including any 

measures that may be planned to minimize reliability impacts. (A-R2)
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NYSRC Reliability Rules

B. TRANSMISSION CAPABILITY - PLANNING

Introduction

The NYS Bulk Power System must be planned with sufficient transmission 

capability to withstand the loss of specified, representative and reasonably 

foreseeable design criteria contingencies at projected customer demand and 

anticipated transfer levels. Application of these design criteria contingencies 

should not result in any criteria violations, or the loss of a major portion of the 

system, or unintentional separation of a major portion of the system. These design 

criteria contingencies are listed in Table A. Analysis of these contingencies 

should include thermal, voltage, and stability assessments as defined by the 

Reliability Rules. The Reliability Rules also apply after any critical generator, 

transmission circuit, transformer, series or shunt compensating device, or high 

voltage direct current (“HVDC”) pole has already been lost, and after generation

and power flows have been adjusted between outages by the use of ten (10) 

minute operating reserve and, where available, phase angle regulator control and 

HVDC control.

Loss of small portions of the NYS Power System (such as radial portions) may be 

tolerated provided they do not jeopardize the reliability of the overall NYS Bulk 

Power System.

Assessment of extreme contingencies recognizes that the NYS Bulk Power System

may be subjected to events which exceed in severity the representative 

contingencies in Table A. These assessments measure the robustness of the 

transmission system, and should be evaluated for risks and consequences. One of 

the objectives of extreme contingency assessment is to determine, through 

planning studies, the effects of extreme contingencies on system performance. 

Extreme contingency assessments provide an indication of system strength, or to
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B. TRANSMISSION CAPABILITY – PLANNING (CONT’D.)

determine the extent of a widespread system disturbance, even though extreme 

contingencies do have low probabilities of occurrence. Extreme contingency 

assessments examine several specific contingencies which are listed in Table B. 

They are intended to serve as a means of identifying some of those particular 

situations that may result in a widespread NYS Bulk Power System shutdown. 

Transmission owners may take actions to reduce the frequency of occurrence of 

extreme contingencies, or to mitigate the consequences that are indicated as the 

result of testing for such contingencies. 

The ability of the NYS Bulk Power System to withstand representative and 

extreme contingencies must be determined by simulation testing of the system as 

prescribed by the Reliability Rules and all applicable NYISO policies, procedures 

and guidelines.

Section B also sets forth a Reliability Rule requiring fault duty levels to be within 

appropriate equipment ratings.

A Special Protection System (SPS) may be employed to provide protection for 

infrequent contingencies or for temporary conditions that may exist such as 

project delays, unusual combinations of system demand and equipment outages or 

unavailability, or specific equipment maintenance outages. An SPS may be 

applied to preserve system integrity in the event of severe facility outages and 

extreme contingencies. The decision to employ an SPS should take into account 

the complexity of the scheme and the consequence of correct or incorrect 

operation as well as benefits. An SPS should be used judiciously and when 

employed, should be installed consistent with good system design and operating 

policy.

This Reliability Rule section also specifies requirements for establishing and 

maintaining a list of NYS Bulk Power System facilities. 
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Table A

Design Criteria Contingencies

a. A permanent three-phase fault on any generator, transmission circuit, transformer or bus section, 

with normal fault clearing.

b. Simultaneous permanent phase-to-ground faults on different phases of each of two adjacent 

transmission circuits on a multiple circuit tower, with normal fault clearing. If multiple circuit 

towers are used only for station entrance and exit purposes, and if they do not exceed five towers 

at each station, then this condition is not applicable.

c. A permanent phase-to-ground fault on any generator, transmission circuit, transformer or bus 

section, with delayed fault clearing.

d. Loss of any element without a fault.

e. A permanent phase-to-ground fault on a circuit breaker, with normal fault clearing. (Normal fault 

clearing time for this condition may not always be high speed.)

f. Simultaneous permanent loss of both poles of a direct current bipolar HVDC facility without an 

ac fault.

g. The failure of a circuit breaker to operate when initiated by a special protection system ("SPS")

following: loss of any element without a fault; or a permanent phase-to-ground fault, with normal 

fault clearing, on any transmission circuit, transformer or bus section.

Table B

Extreme Contingencies

a. Loss of the entire capability of a generating station.

b. Loss of all transmission circuits emanating from a generation station, switching station, d-c 

terminal, or substation.

c. Loss of all transmission circuits on a common right-of-way.

d. Permanent three-phase fault on any generator, transmission circuit, transformer, or bus section, 

with delayed fault clearing and with due regard to reclosing.

e. The sudden loss of a large load or major load center.

f. The effect of severe power swings arising from disturbances outside the NYS Bulk Power System.

g. Failure of a SPS to operate when required following the normal contingencies listed in Table A.

h. The operation or partial operation of a SPS for an event or condition for which it was not intended 

to operate.

i. Sudden loss of fuel delivery system to multiple plants (i.e. gas pipeline contingencies).
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B. TRANSMISSION CAPABILITY – PLANNING (CONT’D.)

Reliability Rules

B-R1. Thermal Assessment

a. Pre-Contingency Thermal Criteria

1. For normal transfers, no transmission facility shall be 

loaded beyond its normal rating.

2. For emergency transfers, no transmission facility shall 

be loaded beyond its normal rating. However, a facility 

may be loaded to the long-term emergency (“LTE”)

rating pre-contingency, if the short-term emergency 

(“STE”) rating is reduced accordingly.

b. Post-Contingency Thermal Criteria

1. For normal transfers, no facility shall be loaded beyond 

its LTE rating following the most severe of design 

criteria contingencies “a” through “g” specified in 

Table A.

An underground cable circuit may be loaded to 

its STE rating following:

Loss of Generation - provided ten (10) minute

operating reserve and/or phase angle regulation 

is available to reduce the loading to its LTE 

rating within fifteen (15) minutes and not cause 

any other facility to be loaded beyond its LTE 

rating.

Loss of Transmission Facilities - provided phase 

angle regulation is available to reduce the 

loading to its LTE rating within fifteen (15)
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B. TRANSMISSION CAPABILITY – PLANNING (CONT’D.)

minutes and not cause any other facility to be 

loaded beyond its LTE rating.

For design criteria contingencies “b”, “c”, “e”, “f”, and 

“g” in Table A that are not confined to the loss of a 

single element, transmission owners may request 

permission from the NYISO to design the system so that 

post-contingency flows up to the STE ratings on the 

remaining facilities can occur. This is permissible 

provided operating measures are available to reduce the 

loading to its LTE rating within fifteen (15) minutes and 

not cause any other facility to be loaded beyond its LTE 

rating.

Design exceptions should be well documented, including 

NYISO comments, and must be approved by the 

NYSRC.

2. For emergency transfers, no facility shall be loaded 

beyond its STE rating following the more severe of 

design criteria contingencies “a” or “d” listed in Table 

A. The STE rating is based on an assumed pre-loading 

equal to the normal rating. Therefore, if the limiting 

facility is loaded above its normal rating precontingency, the STE rating must be reduced 

accordingly.

B-R2. Voltage Assessment

Reactive power shall be maintained within the NYS Bulk Power 

System in order to maintain voltages within applicable 
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B. TRANSMISSION CAPABILITY – PLANNING (CONT’D.)

pre-disturbance and post-disturbance limits for both normal and 

emergency transfers, consistent with the Reliability Rules and all 

applicable guidelines and procedures.

a. Pre-Contingency Voltage Criteria

For both normal and emergency transfers, no bus voltage 

shall be below its pre-contingency low voltage limit nor be 

above its pre-contingency high voltage limit.

b. Post-Contingency Voltage Criteria

No bus voltage shall fall below its post-contingency low 

voltage limit nor rise above its post-contingency high voltage 

limit. For normal transfers, design criteria contingencies 

“a” through “g” specified in Table A are applicable. For 

emergency transfers, design criteria contingencies “a” 

through “g” specified in Table A are applicable.

B-R3. Stability Assessment

Stability of the NYS Bulk Power System shall be maintained 

during and following the most severe of the design criteria 

contingencies “a” through “g” specified in Table A, with due 

regard to reclosing. For each of those design criteria contingencies 

that involves a fault, stability shall be maintained when the 

simulation is based on fault clearing initiated by the “system A” 

protection group and also shall be maintained when the simulation 

is based on fault clearing by the “system B” protection group.

a. System Stability

1. For normal transfers, stability of the NYS Bulk Power 

System shall be maintained during and after the most 
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B. TRANSMISSION CAPABILITY – PLANNING (CONT’D.)

severe of design criteria contingencies “a” through “g” 

specified in Table A. The NYS Bulk Power System must be 

stable if the faulted element is re-energized by delayed reclosing 

before any manual system adjustment, unless specific alternate 

procedures are documented. 

2. For emergency transfers, stability of the NYS Bulk Power 

System shall be maintained during and after the more severe of 

design criteria contingencies “a” through “g” specified in 

Table A. The NYS Bulk Power System must also be stable if the 

faulted element is re-energized by delayed reclosing before any 

manual system adjustment. Emergency transfer levels may 

require generation adjustment before manually reclosing 

faulted elements not equipped with automatic reclosing or 

whose automatic reclosing capability has been rendered 

inoperative.

b. Generator Unit Stability

With all transmission facilities in service, generator unit 

stability shall be maintained on all facilities not directly 

involved in clearing the fault for design criteria 

contingencies “a” through “g” specified in Table A.

B-R4. Extreme Contingency Assessment

Assessment of the extreme contingencies listed in Table B shall 

examine post-contingency steady state conditions as well as 

overload cascading and voltage collapse. Pre-contingency load

flows chosen for analysis should reflect reasonable power transfer 

conditions. The testing shall be conducted at megawatt (“MW”) 

B. TRANSMISSION CAPABILITY – PLANNING (CONT’D.)
NYSRC Reliability Rules

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23

transfers at a level which is expected at least 75% of the time on a 

load flow duration basis, but not to exceed the maximum 

operating limit for the interface being tested. This may be at or 

near the normal transfer limit for some interfaces. Analytical 

studies shall be performed to determine the effect of the extreme 

contingencies in Table B.

After due assessment of extreme contingencies, measures will be 

utilized where appropriate, to reduce the frequency of occurrence 

of such contingencies, or to mitigate the consequences that are 

indicated as a result of testing for such contingencies.

B-R5. Restoration

System expansion or reconfiguration plans shall include an 

assessment of their impact on the existing NYCA System 

Restoration Plan (NYCA SRP).

B-R6. List of NYS Bulk Power System Facilities

The NYISO shall develop, maintain, and keep current a list of NYS 

Bulk Power System facilities.

B-R7. Fault Current Assessment

Fault duty levels shall be within appropriate equipment ratings.

Measurements

B-M1. The NYISO shall ensure that the thermal, voltage, short-circuit, and 

stability performance of the NYS Bulk Power System, as planned, is in 

accordance with NYSRC thermal, voltage, fault duty, and stability

B. TRANSMISSION CAPABILITY – PLANNING (CONT’D.)
NYSRC Reliability Rules

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assessment criteria, and applicable NPCC Criteria. (B-R1 through BR3 and B-R7)

B-M2. The NYISO shall assess the risks and system performance resulting 

from the extreme contingencies in Table B, and shall utilize measures, 

where appropriate, to reduce the frequency of occurrence of such 

contingencies, or to mitigate the consequences that are indicated as a 

result of testing for such contingencies. (B-R4)

B-M3. The NYISO shall develop, maintain, and execute procedures to 

evaluate system expansion or reconfiguration plans and identify their 

impact on the NYCA SRP. This process shall be performed every 

year as part of the NYISO annual transmission assessment. Any 

impacts identified shall be described in terms of how and where the 

SRP may need to be modified, and made available to the NYISO 

Operating Group and the operating function of the appropriate 

transmission owners for consideration in the annual review and update 

of NYISO and transmission owner restoration plans as required by 

Reliability Rule G-R1. (B-R5)

B-M4. The NYISO shall establish and maintain a procedure for developing a 

list of NYS Bulk Power System facilities. On request, the NYISO shall 

submit this procedure and list of NYS Bulk Power System facilities to 

the NYSRC for review. The NYS Bulk Power System facilities list shall 

be published in the annual NYISO “Load and Capacity Data Report” or 

other publication approved by the NYSRC. (B-R6)
NYSRC Reliability Rules

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B. TRANSMISSION CAPABILITY – PLANNING (CONT’D.)

Guidelines

NYISO Voltage Limit Guideline – Refer to Appendix E of the NYISO 

“Transmission Expansion and Interconnection Manual”. This guideline should be 

used in transmission studies in accordance with Reliability Rule B-R2.

NYISO Stability Limit Guideline – Refer to Appendix F of the NYISO

“Transmission Expansion and Interconnection Manual”. This guideline should be 

used in transmission studies in accordance with Reliability Rule B-R3.

NYPP Tie Line Ratings Task Force Report – Refer to the Planning Reference 

Documents on the NYISO web site. This guideline should be used in transmission 

studies accordance with Reliability Rule B-R1.

NYISO Fault Current Assessment Guideline – Refer to the Planning Reference 

Documents on the NYISO web site. This guideline should be used in transmission 

studies in accordance with Reliability Rule B-R7.

The NYISO documents referenced above can be found on the NYISO web site, 

www.nyiso.com/services. 

Thermal and voltage ratings for facilities to be included in transmission planning 

assessments are to be determined by the transmission owner, or operator pursuant 

to contractual arrangement, consistent with applicable NYISO guidelines. These 

ratings and limits will be used for all studies conducted by the NYISO and 

transmission owners and in the operation of the NYS Bulk Power System.
NYSRC Reliability Rules

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NYSRC Reliability Rules

C. RESOURCE, SYSTEM & DEMAND DATA 

REQUIREMENTS

Introduction

System modeling is the first step toward planning and operating a reliable NYS 

Bulk Power System. The development of system modeling data to realistically 

simulate the operation of resource and transmission facilities is essential for 

planning and operating studies used to assess electric system reliability. To 

achieve this purpose, the Reliability Rules establish requirements for the 

development and submission of complete, accurate, and timely data necessary for 

NYSRC studies for establishing statewide IRM requirements and various NYISO

resource and transmission analyses and assessments required by the Reliability 

Rules and NYISO procedures. 

System modeling data required under this section includes resource capacity

verification testing and availability, system data, and load forecasting, and data 

from disturbance recording devices

Reliability Rules

C-R1. Verification Testing of Resource Capacity

Equipment used for providing resource capacity shall be tested to 

verify capacity data. 

C-R2. Generating Unit Availability

Accurate generating unit outage data needed to analyze and model 

the reliability of the NYCA shall be collected and maintained.
NYSRC Reliability Rules

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C. RESOURCE, SYSTEM & DEMAND DATA REQUIREMENTS (CONT’D.)

C-R3. Load Forecasting

Actual and forecast demands and net energy for load data required 

for the analysis of the reliability of the NYCA shall be developed, 

provided, and maintained on an aggregated statewide, 

transmission district, and zone basis.

C-R4. System Data Requirements

Accurate load flow, short circuit, and stability data bases required 

for planning and operating studies of the NYS Bulk Power System

shall be developed and maintained. The data shall include 

appropriate detail from adjacent control areas.

C-R5. Disturbance Recording

Disturbance recording devices shall be installed to ensure data is 

available to assist in the analysis of NYCA performance during 

system disturbances.

Measurements

C-M1. The NYISO shall establish and maintain procedures for 

resource capacity data verification testing or demonstration for all 

equipment utilized for providing installed capacity and reactive power 

capacity to the NYCA. 

The data to be provided to the NYISO shall include resource net

dependable capacity for all resources that are participating in the 

NYISO installed capacity market, and reactive power capacity for all 

resources that are voltage support ancillary service providers. The 

procedures shall include requirements for resource providers to 

provide to the NYISO the net MW at the time of the DMNC test, and 
NYSRC Reliability Rules

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C. RESOURCE, SYSTEM & DEMAND DATA REQUIREMENTS (CONT’D.)

the net MW and gross MVAr quantities taken simultaneously at the 

time of the reactive power capability test. These reactive power tests 

shall be undertaken for both leading and lagging reactive power 

operation. 

NYISO procedures shall further require that generation equipment 

owners perform leading reactive power tests once every three calendar 

years and lagging reactive power tests once every calendar year for all 

generators that are voltage support ancillary service providers. These 

tests shall verify the maximum reactive power capacity offered into 

the voltage support service program. The AVR shall be in service at all 

times during the test. The resource capacity test results reported to the 

NYISO shall include the actual test date(s) for each generator and the 

MW output at the time of the test. 

In addition, NYISO procedures shall include a requirement that, 

following leading reactive power testing, each generation equipment 

owner shall provide a certification to the NYISO that the data 

submitted for the leading reactive power test accurately demonstrates 

the maximum leading reactive power of the generator at the time of the 

test.

The NYISO shall provide dependable net capacity and gross reactive 

power capacity data to the operating function of the Transmission 

Owner that the resource connects to, within 60 calendar days 

following the close of the seasonal capability period or annual test 

period, respectively. Documentation of the NYISO procedures and 

verification results shall be provided to the NYSRC upon request. 
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C. RESOURCE, SYSTEM & DEMAND DATA REQUIREMENTS (CONT’D.)

C-M2. Owners of resources responsible for providing ICAP shall seasonally 

verify the net dependable capacity of their equipment and report these 

results to the NYISO in accordance with NYISO procedures and 

schedules as required in Measurement C-M1. (C-R1)

C-M3. Generation equipment owners shall annually perform lagging reactive 

power tests for all generators that are voltage support ancillary service 

providers. Generation equipment owners shall perform leading 

reactive power tests once every three calendar years for all generators 

that are voltage support ancillary service providers. These tests shall 

verify the maximum reactive power capacity offered into the voltage 

support service program. Test results shall be reported to the NYISO, 

in accordance with NYISO procedures and schedules as required in 

Measurement C-M1.

C-M4. The NYISO shall establish, maintain and follow procedures to address 

Installed Capacity Provider generating unit outage data reporting 

requirements and methods of processing outage data. These 

procedures shall be designed to provide complete, consistent and 

accurate data to support NYSRC and NYISO reliability studies. This 

data shall include, but not be limited to, forced, partial and 

maintenance outage statistics. NYISO outage data reporting and 

processing procedures shall include the following requirements: 

Outage Data Reporting Procedure

1. Installed Capacity Provider generating unit outage data 

reporting instructions.

2. Installed Capacity Provider outage data reporting schedules.
NYSRC Reliability Rules

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C. RESOURCE, SYSTEM & DEMAND DATA REQUIREMENTS (CONT’D.)

3. Training programs for Installed Capacity Providers that focus 

on proper generating unit outage data collection and reporting 

methods for submission of accurate data to the NYISO.

4. The consequences to an Installed Capacity Provider of failing 

to submit complete, accurate and timely data to the NYISO. 

Outage Data Processing Procedures

5. Due diligence NYISO processes for screening of all generating 

unit outage data received from Installed Capacity Providers. 

These processes shall be designed to screen outage data and 

replace misreported outage data or Suspect Data with corrected 

or proxy data as necessary, and shall be employed by the 

NYISO before the data is used in NYSRC and NYISO reliability 

studies. On request by the NYSRC, the NYISO shall make 

available for inspection documentation covering its processes 

for reviewing and screening outage data.

C-M5. Installed Capacity Providers located in or serving the NYCA shall

provide generating unit outage data for their generating units in 

accordance with NYISO procedures, tariffs and schedules for reporting 

outage data to the NYISO. 

C-M6. The NYISO shall annually prepare, from generating unit outage data 

received under C-M5, a document depicting outage data statistics to be 

specified by the NYSRC, and submitted in accordance with NYSRC

time schedules.

C-M7. The NYISO shall have documentation identifying the scope and details 

of the actual and forecast (a) demand data and (b) net energy for load

data to be reported for system modeling and reliability analyses. The 

documentation of the scope and details of the data reporting 

requirements shall be available to the NYSRC on request. (C-R3)
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C. RESOURCE, SYSTEM & DEMAND DATA REQUIREMENTS (CONT’D.)

C-M8. The following information shall be provided annually to the NYSRC as 

specified by NYISO procedures required under C-M7:

a. Annual peak hour actual demands in MW and net energy for load

in gigawatthours (“GWh”) for the prior year, on an aggregated 

statewide and transmission district basis.

b. Annual peak hour forecast demands in MW (summer and winter) 

in MW and annual net energy in GWh for at least five years and to 

ten years into the future, on an aggregated statewide and 

transmission owner basis. In addition, annual peak hour forecast 

demands for the NYCA zones, for a specified future period, will be 

provided to the NYSRC on request. (C-R3)

C-M9. The NYISO shall establish and maintain procedures for the 

development and maintenance of load flow, short circuit, and stability 

data bases. These procedures shall: 

1. Require Market Participants and Developers to report to the 

NYISO accurate equipment data, including changes, which affect 

these data bases. The procedure shall address appropriate time 

requirements for reporting such data.

2. Include guidelines for checking the reasonableness of equipment 

data (load flow, short circuit and stability data) to identify Suspect 

Data. The guidelines shall specify reasonable data parameters. 

3. Require the NYISO to apply the guidelines in C-M9.2 to data 

provided to the NYISO. 

4. Require the NYISO to request verification or corrections of any 

Suspect Data from the Market Participant or Developer that 

provided the data.
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C. RESOURCE, SYSTEM & DEMAND DATA REQUIREMENTS (CONT’D.)

C-M10. Load flow, short-circuit, and stability data bases shall be updated by 

the NYISO on an annual basis or whenever system changes warrant an 

update, as specified by NYISO procedures required under 

Measurement C-M9. These data bases shall be made available per 

NYISO procedures. (C-R4)

C-M11. Market Participants and Developers shall:

1. Provide to the NYISO accurate load flow, short circuit and stability 

data in the time frame and format as specified by NYISO

procedures required under C-M9. This data will be used to 

maintain up-to-date data bases required under Measurement CM10.

2. Respond to NYISO requests for data verification or correction of 

Suspect Data.

3. Review and check their equipment data (load flow, short circuit 

and stability data) within data bases provided by the NYISO to 

ensure accuracy.

C-M12. The NYISO shall develop requirements and procedures for the 

installation of disturbance recording devices and the reporting of data 

to assist in the analysis of NYCA performance during system 

disturbances. The NYISO shall maintain a database of all NYCA

disturbance recording device installations. (C-R5)

C-M13. Market Participants shall install disturbance monitoring devices and 

report data in accordance with NYISO requirements and procedures. 

(C-R5)
NYSRC Reliability Rules

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NYSRC Reliability Rules

D. OPERATING RESERVES

Introduction

The Reliability Rules in this Section establish the minimum level of operating 

reserves to be provided in the NYCA. Resource capacity in excess of projected 

load requirements is necessary to assure an acceptable degree of service 

continuity. 

The factors considered in establishing the minimum desired magnitude of 

operating reserve include unexpected resource and transmission contingencies, 

regulation of frequency and tie line flow, and load forecast error. The nature and 

characteristics of the various types of synchronized and non-synchronized 

resource capacity which comprise the operating reserve have been considered in 

the formulation of NYCA's operating reserve requirements. 

Reliability Rules

 D-R1. Operating Resource Adequacy

Scheduled outages and deratings of resources shall be coordinated 

in such a manner that the available resources, with due allowance 

for forced outages and deratings, will be adequate to meet NYCA’s

forecasted load and operating reserve requirements. Procedures 

shall be developed consistent with the Reliability Rules that: 

maintain a minimum operating reserve level for each type of 

reserve, in both computer directed and non-computer directed 

dispatch; define how anticipated future shortages of reserve will be 

handled; and defines coordination with other Market Participants

in NPCC and PJM to share reserves. The procedure must include 
NYSRC Reliability Rules

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D. OPERATING RESERVES (CONT’D.)

forecasts for weekly, daily, and hourly reserves, and reflect the 

impact of capability, loads, response rates, transactions, 

transmission limitations, and unit commitment. These forecasts 

must also support unit commitment.

D-R2. Minimum Operating Reserve Requirement

The minimum operating reserve requirement of the NYISO shall 

be the sum of:

a. Sufficient ten (10) minute operating reserve to replace the 

operating capacity loss caused by the most severe 

contingency observed under normal transfer criteria 

multiplied by the Contingency Reserve Adjustment Factor.

b. Sufficient thirty (30) minute operating reserve equal to onehalf of the ten (10) minute operating reserve necessary to 

replace the operating capacity loss caused by the most 

severe contingency observed under normal transfer criteria.

At all times sufficient ten (10) minute operating reserve shall be 

maintained to cover the energy loss due to the most severe normal 

transfer criteria contingency within the NYCA or the energy loss 

caused by the cancellation of an interruptible energy purchase 

from another system, whichever is greater multiplied by the 

Contingency Reserve Adjustment Factor.
NYSRC Reliability Rules

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D. OPERATING RESERVES (CONT’D.)

D-R3. Availability and Category

a. The ten (10) minute operating reserve portion of the NYISO’s

minimum operating reserve requirement shall be fully available 

within ten (10) minutes and shall be in the following categories: 

1. Synchronized Operating Reserve - At least one-half of the 

ten (10) minute operating reserve will consist of unused 

resource capacity which is synchronized and ready to 

achieve claimed capacity, or resource capacity which can be 

made available by curtailing pumping hydro units, or 

canceling energy sales to other systems.

2. Non-Synchronized Ten Minute (10) Operating Reserve - The 

remainder of the ten (10) minute operating reserve may be 

composed of non-synchronized resource capacity such as 

hydro, pumped storage hydro, and quick start combustion 

generation, which can be synchronized and loaded to 

claimed capacity in ten (10) minutes or less, and 

interruptible load that can be activated in ten (10) minutes 

or less.

b. The thirty (30) minute operating reserve portion of the NYISO’s

operating reserve requirement is that portion of unused 

resource capacity or interruptible load which can and will be 

made fully available as promptly as possible, but in no more 

than thirty (30) minutes.

c. Resource capacity associated with the delivery of interruptible 

sales to adjacent control areas may be included as operating 

reserve in the category agreed upon by the purchaser.
NYSRC Reliability Rules

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D. OPERATING RESERVES (CONT’D.)

D-R4. Restoration of Ten (10) Minute Reserves

Following a contingency, the ten (10) minute operating reserve shall 

be restored within thirty (30) minutes of the time that the

contingency occurred, or sooner if possible.

Measurements

D-M1. Retired

D-M2. The NYISO shall maintain procedures and systems that ensure the 

adequacy of operating reserves, and shall provide documentation of 

these procedures and systems. The NYISO must notify the NYSRC of 

any changes to these procedures and systems. (D-R1 through D-R4)

D-M3. Retired
NYSRC Reliability Rules

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NYSRC Reliability Rules

E. TRANSMISSION CAPABILITY - OPERATING

Introduction

This Section sets forth Reliability Rules for establishing operating transmission 

capabilities. NYSRC operating Reliability Rules provide the basis for application 

of the planning Reliability Rules to inter-control area and NYS Bulk Power 

System operation. They represent the minimum level of security that shall apply to 

the operation of the NYS Bulk Power System. Where NYS Bulk Power System or 

inter-control area security is affected, operating limits are established so that the 

contingencies stated in Table A can be withstood without adversely affecting the 

reliability of the NYS Bulk Power System or neighboring systems.

When adequate facilities are available to supply firm load, pre-contingency 

voltages, line loadings, and equipment loadings shall be within applicable normal 

voltage limits and thermal ratings. Unless specific instructions describing 

alternate action are in effect, normal transfers shall be such that manual reclosing 

of a faulted element can be carried out before any manual system adjustment, 

without affecting the stability of the NYS Bulk Power System.

When necessary to ensure that adequate facilities continue to be available to 

supply firm load in the NYCA or a portion of the NYCA, transfers may be 

increased to the point where pre-contingency voltages, line loadings, and 

equipment loadings are within applicable emergency voltage limits and thermal 

ratings. Emergency transfer levels may require generation adjustment before 

manually reclosing faulted elements.

When adequate NYS Bulk Power System facilities are not available, SPSs may be 

employed to maintain system security. The requirements of SPSs should be 

defined by the NYISO. 
NYSRC Reliability Rules

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E. TRANSMISSION CAPABILITY – OPERATING (CONT’D.)

Two categories of transmission transfer capabilities, normal and emergency, are 

applicable. Normal transfer capabilities are to be observed unless emergency

transfer criteria are invoked by the NYISO.

This section of the Reliability Rules requires assessments to evaluate fault duty 

levels and to develop appropriate mitigation plans in the event equipment ratings 

are exceeded.

The transmission owners establish and implement procedures for meeting the 

NYSRC Reliability Rules that apply to specific conditions on portions of the NYS 

Transmission System not included in the NYISO Secured Transmission System. 

These procedures are known as “Applications of the Reliability Rules”. These 

Applications require close coordination between the transmission owners and the 

NYISO in order to maintain the reliability of the NYS Power System. The 

NYSRC Reliability Rules provide the NYISO with the responsibility of 

maintaining the Applications, approving modifications or new Applications, and 

for securing the needed cooperation by the transmission owners. 

Local conditions may require criteria which are more stringent than those set out 

herein. Any constraints imposed by these more stringent criteria will be observed 

in daily operations. The criteria will not necessarily apply to portions of a 

transmission owner’s system where instability or overloads will not jeopardize the 

reliability of the NYS Bulk Power System, unless otherwise incorporated as local 

reliability rules.

Local conditions requiring criteria which are more stringent than those set out 

herein shall be formulated as Local Reliability Rules. These Local Reliability 

Rules are provided in Reliability Rules Section I. Any constraints imposed by 

such local reliability rules shall be observed in daily operations.
NYSRC Reliability Rules

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E. TRANSMISSION CAPABILITY – OPERATING (CONT’D.)

Subsequent to the determination of the day-ahead commitment of generating units 

by the NYISO, transmission owners will have the opportunity to review the unit 

commitment. To the extent that operating circumstances may adversely impact 

short-term reliability of the transmission owner’s local system and such operating 

circumstances have not been addressed in any Reliability Rules, inclusive of local 

reliability rules, the transmission owner will have the flexibility to request 

additional generating units to be committed for service. The final commitment 

decision will rest with the NYISO and will be posted on the NYISO’s Open

Access Same-Time Information System (“OASIS”).

Reliability Rules

E-R1. Thermal Assessment

a. Pre-Contingency Thermal Criteria

1. For normal transfers, no transmission facility shall be 

loaded beyond its normal rating.

2. For emergency transfers, no transmission facility shall be 

loaded beyond its normal rating. However, a facility may be 

loaded up to the LTE rating pre-contingency if the STE 

rating is reduced accordingly.

b. Post-Contingency Thermal Criteria

1. For normal transfers, no facility shall be loaded beyond its 

LTE rating following the most severe of contingencies "a" 

through "g" specified in Table A in Reliability Rule Section 

B.

An underground cable circuit may be loaded to its STE 

rating following:
NYSRC Reliability Rules

January 7, 2011

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E. TRANSMISSION CAPABILITY – OPERATING (CONT’D.)

Loss of Generation - provided ten (10) minute operating

reserve and/or phase angle regulation is available to reduce 

the loading to its LTE rating within fifteen (15) minutes and 

not cause any other facility to be loaded beyond its LTE 

rating.

Loss of Transmission Facilities - provided phase angle 

regulation is available to reduce the loading to its LTE 

rating within fifteen (15) minutes and not cause any other 

facility to be loaded beyond its LTE rating.

For contingencies "b", "c", "e", "f", and "g" in Table A 

that are not confined to the loss of a single element, 

transmission owners may request the NYISO for an 

exception to allow the post-contingency flow on a facility up 

to its STE rating. This is permissible provided operating 

measures are available to reduce the flow below the LTE 

rating within fifteen (15) minutes and not cause any other 

facility to be loaded beyond its LTE rating.

Operating exceptions shall be well documented, including 

NYISO comments, and must be approved by the NYSRC.

2. For emergency transfers, no facility shall be loaded beyond 

its STE rating following the more severe of contingencies 

"a" or "d" listed in Table A. The STE rating is based on an 

assumed pre-loading equal to the normal rating. A limiting 

facility may be loaded up to the LTE rating, precontingency, if the STE rating is reduced accordingly.
NYSRC Reliability Rules

January 7, 2011

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E. TRANSMISSION CAPABILITY – OPERATING (CONT’D.)

E-R2. Voltage Assessment

Reactive power shall be maintained within the NYS Bulk Power 

System in order to maintain voltages within applicable predisturbance and post-disturbance limits, for both normal and 

emergency transfers, as specified below.

a. Pre-Contingency Voltage Criteria

For both normal and emergency transfers, no bus voltage will 

be below its pre-contingency low voltage limit nor be above its 

pre-contingency high voltage limit. The pre-contingency voltage 

on a bus is permitted to operate below its pre-contingency low 

voltage limit or above its pre-contingency high voltage limit if 

all corrective actions short of load shedding have been taken 

and conditions are not indicative of system problems, or 

sufficient time and resources exist to take corrective action to 

prevent voltage collapse should a contingency occur.

b. Post-Contingency Voltage Criteria

No bus voltage will fall below its post-contingency low voltage 

limit nor rise above its post-contingency high voltage limit. For 

normal transfers, contingencies "a" through "g" specified in 

Table A are applicable. For emergency transfers, contingencies 

"a" through “g” specified in Table A are applicable. 

E-R3. Stability Assessment

System stability transfer limits shall be consistent with the 

Reliability Rules and all applicable guidelines and procedures in 

the NYISO Guideline #3-0, “Guideline for Stability Analysis and 

Determination of Stability-Based Transfer Limits”.
NYSRC Reliability Rules

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E. TRANSMISSION CAPABILITY – OPERATING (CONT’D.)

a. For normal transfers, stability of the NYS Bulk Power System

shall be maintained during and after the most severe of 

contingencies "a" through "g" specified in Table A. The NYS 

Bulk Power System must also be stable if the faulted element as 

described in Table A is re-energized by delayed reclosing

before any manual system adjustment, unless specific alternate 

procedures are documented.

b. For emergency transfers, when firm load cannot be served, 

stability of the NYS Bulk Power System shall be maintained 

during and after contingencies "a" through "g" specified in 

Table A. The NYS bulk power system must also be stable if the 

faulted element as described in Table A is re-energized by 

delayed reclosing before any manual system adjustment.

E-R4. Post-Contingency Operation

Immediately after the occurrence of a contingency, the status of 

the NYS Bulk Power System shall be assessed and transfer levels 

shall be adjusted, if necessary, to prepare for the next contingency. 

If the readjustment of generation, including the use of operating 

reserve, phase angle regulator control, and HVDC control is not 

adequate to restore the system to a secure state, then other 

measures such as voltage reduction and shedding of firm load may 

be required. System adjustments shall be completed as quickly as 

possible, but in all cases within thirty (30) minutes after the 

occurrence of the contingency.

Voltage reduction need not be initiated and firm load need not be 

shed to observe a post-contingency loading requirement until the 

contingency occurs, provided that adequate response time for this 

action is available after the contingency occurs and other measures 
NYSRC Reliability Rules

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E. TRANSMISSION CAPABILITY – OPERATING (CONT’D.)

shall maintain post-contingency loadings within applicable 

emergency ratings. Emergency measures, including the preshedding of firm load, if necessary, must be effected to limit 

transfers to within the requirements of E-R1.a.2, E-R1.b.2, ER2.b, and E-R3.b.

E-R5. Outage Coordination

Scheduled outages of facilities that affect the reliability of the NYS 

Bulk Power System shall be coordinated sufficiently in advance of 

the outage to permit the affected systems to maintain reliability. 

The adjacent systems shall be notified of scheduled or forced 

outages of any facility that may impact another system(s) 

reliability and of any other abnormal transmission configuration 

which may impact the reliability of the NYS Bulk Power System. A 

list of facilities that must be secured by the NYISO and require 

coordination shall be maintained including any other abnormal 

transmission configuration which may impact the reliability of the 

NYS Bulk Power System. Work on facilities which impact the 

reliability of the NYS Bulk Power System shall be expedited.

Appropriate adjustments shall be made to NYCA operations to 

accommodate the impact of protection group outages. For typical 

periods of forced or maintenance outage of a protection group, it 

can be assumed, unless there are indications to the contrary, that 

the remaining protection will function as designed. If the protection 

group will be out of service for an extended period of time (as 

defined in NPCC criteria), additional adjustments to operations 

may be appropriate considering other system conditions and the 

consequences of possible failure of a remaining protection group.
NYSRC Reliability Rules

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E. TRANSMISSION CAPABILITY – OPERATING (CONT’D.)

E-R6. Operation During Impending Severe Weather

During periods when severe weather (such as, but not limited to, 

tornadoes or hurricanes) exists or is forecast to occur, it may be 

necessary to take steps in addition to those procedures normally 

followed to maintain system security. When a situation exists in 

which the effects of impending severe weather could severely 

jeopardize the security of the NYS Bulk Power System, corrective 

actions which would be necessary to protect for one transmission 

contingency greater than the normal criteria within the affected 

area shall be carried out.

Generation may be ordered to full operating capacity and 

transmission facilities out of service for maintenance may be 

ordered restored to service.

The NYISO shall enter this mode of operation for those portions of 

the NYS Bulk Power System affected by actual or impending severe 

weather when requested to do so by the affected transmission 

owners, or at any other times when it deems necessary to preserve 

the security and reliability of the NYS Bulk Power System.

E-R7. Operation During a Severe Solar Magnetic Disturbance

During periods when a severe solar magnetic disturbance 

(“SMD”) exists or is forecast to occur, it may be necessary for the 

NYISO and transmission owners to take steps in addition to those 

procedures normally followed to maintain system security. Such 

steps may include, but are not limited to, restoration of 

transmission facilities that are out of service, cancellation of 

scheduled outages, and adjustment of reactive power dispatch.
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E. TRANSMISSION CAPABILITY – OPERATING (CONT’D.)

The NYISO shall enter this mode of operation for those portions of 

the NYS Bulk Power System affected by an SMD when requested to 

do so by the affected transmission owners, or at any other times 

when it deems necessary to preserve the security and reliability of 

the NYS Bulk Power System.

E-R8. Fault Current Assessment

Fault duty levels shall be within appropriate equipment ratings.

E-R9. Applications of the NYSRC Reliability Rules

Applications of the NYSRC Reliability Rules shall be established 

and maintained.

E-R10. Exceptions to the NYSRC Reliability Rules

A list of all exceptions to the NYSRC Reliability Rules shall be 

established and maintained.

Measurements

E-M1. The NYISO shall maintain procedures and systems that ensure that 

appropriate actions are taken when thermal, voltage, and/or stability

limits are violated. The NYISO must notify the NYSRC of any changes 

to these procedures and systems. (E-R1 through E-R3)

E-M2. Retired

E-M3. The NYISO shall maintain procedures and systems which ensure that 

outages of transmission facilities are coordinated in such a manner to 

ensure reliability. The NYISO must notify the NYSRC of any changes 

to these procedures and systems. (E-R5)
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E. TRANSMISSION CAPABILITY – OPERATING (CONT’D.)

E-M4. The NYISO shall maintain procedures and systems which allow for 

more stringent operating restrictions prior to, and during, severe 

weather conditions, and severe solar magnetic disturbances. The 

NYISO must notify the NYSRC of any changes to these procedures and 

systems. (E-R6, R7)

E-M5. Retired

E-M6. a. The NYISO shall perform pre-seasonal assessments, and additional

re-evaluations if required by system changes, to evaluate fault duty

at each NYS Bulk Power System station. The NYISO shall notify

the applicable equipment owner and other potentially affected

Market Participants of any location expected to exceed equipment

ratings.

b. After the equipment owner has reported its findings on the

NYISO’s assessment (as required by Measurement E-M7), the

NYISO, in consultation with the equipment owner and the other

potentially affected Market Participants, shall develop, if

necessary, an appropriate mitigation plan. (E-R8)

E-M7. After evaluating and considering the NYISO assessment concerning a 

location for which fault duty levels may exceed appropriate equipment 

ratings, the applicable equipment owner shall assess the condition and 

report its findings to the NYSIO in accordance with NYISO 

requirements (see Measurement E-M6a). (E-R8)

E-M8. The NYISO shall establish and maintain Applications of the NYSRC

Reliability Rules (Applications) consisting of transmission owner

procedures for meeting the NYSRC Reliability Rules that apply to 

specific system locations or conditions. The list of Applications shall

be posted on the NYISO web site. The transmission owners shall 

prepare new or revised Applications as required. Applications 
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E. TRANSMISSION CAPABILITY – OPERATING (CONT’D.)

proposed by transmission owners shall be referred to the NYISO for 

approval. The NYISO shall advise the NYSRC when Application 

changes occur. The NYISO shall prepare a procedure addressing the 

above requirements. (E-R9)

E-M9 The NYISO shall implement actions required for granting new

exceptions or modifying or removing current exceptions, as described 

in NYSRC Policy 1, Procedure for Reviewing, Developing, Modifying, 

and Disseminating NYSRC Reliability Rules. These required NYISO 

actions shall include:

1. Request each Transmission Owner, at least annually, to assess its 

exceptions and to determine whether it wishes to request the 

NYSRC to grant a new exception or modify or remove a current 

exception.

2. Implementation of a request from the NYSRC to review an 

application for a new exception or the renewal or modification of a 

current exception that:

• The NYSRC has received directly from a Market Participant or

• The NYSRC has received from a Transmission Owner via the 

Annual Exception Review.

3. Following its review pursuant to paragraph 2 above, the NYISO

shall notify the NYSRC if it recommends that the NYSRC approve 

the granting of the new exception, or whether the current exception 

should be removed or modified as proposed. The NYISO shall 

document the reasons for its recommendation, including a finding 

that there would be no adverse impact to reliability upon issuance 

of the new exception or removal or modification of the current 

exception. If the NYISO recommends that the exception request 
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E. TRANSMISSION CAPABILITY – OPERATING (CONT’D.)

should be rejected by the NYSRC, the NYISO shall document its 

reasons for such a recommendation.

Guidelines

NYISO Transmission Operating Guideline for Voltage Analysis and 

Determination of Voltage-Based Transfer Limits. This guideline should be used 

in operating studies in accordance with Reliability Rule E-R2.

 

NYISO Stability Limit Guideline – Refer to Appendix F of the NYISO 

“Transmission Expansion and Interconnection Manual”. This guideline should be 

used in operating studies in accordance with Reliability Rule E-R3.

NYPP Tie Line Ratings Task Force Report – Refer to the Planning Reference 

Documents on the NYISO web site. This guideline should be used in accordance 

with operating studies in accordance with Reliability Rule E-R1.

NYISO OP1 Voltage Limits – Refer to Exhibit A-3 of the NYISO document, 

“System Operation Procedures”. This guideline should be used in operating 

studies in accordance with Reliability Rule E-R2.

NYISO Fault Current Assessment Guideline – Refer to the Planning Reference 

Documents on the NYISO web site. This guideline should be used in operating 

studies in accordance with Reliability Rule E-R8. 

The NYISO documents referenced above can be found on the NYISO web site,

www.nyiso.com/services. 
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NYSRC Reliability Rules

F. OPERATION DURING MAJOR EMERGENCIES

Introduction

The NYISO develops, maintains, and implements plans to mitigate major 

emergencies. This Section sets forth Reliability Rules to be used by the NYISO in 

the event of eight types of major emergencies. 

After declaration of a major emergency, any request made by the NYISO to a 

Market Participant dispatcher for remedial action including, but not limited to, 

load shedding, shall be considered an order to effect such remedial action. 

Normally, those orders shall be made over the hot line to the transmission owners.

Reliability Rules

F-R1. Transmission Thermal Overloads

If a transmission facility, which constitutes a part of the NYS Bulk 

Power System, becomes overloaded, relief measures shall be 

applied immediately to bring the loading within established 

ratings.

a. When a facility becomes loaded above its LTE rating, but 

below its STE rating corrective action which may include 

voltage reduction and/or load shedding, must be taken to return 

the loading on the facility to its LTE rating or lower within 

fifteen (15) minutes.

b. When a facility becomes loaded at or above its STE rating, 

immediate corrective action which may include voltage 

reduction and/or load shedding, must be initiated to reduce the
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F. OPERATION DURING MAJOR EMERGENCIES (CONT’D.)

loading on the facility to below its STE rating within five (5) 

minutes and furthermore, to continue to reduce the loading on 

the facility to below its LTE rating within ten (10) minutes from 

the initial overload. If the loading is substantially above the 

STE rating, load relief should be considered as the initial action 

to be taken.

c. After the loading on a facility has been reduced below its LTE 

rating additional corrective action, excluding further voltage 

reduction and/or load shedding, should be taken to reduce the 

loading on the facility to below its normal rating within thirty 

(30) minutes of the initial overload. In the event this cannot be 

accomplished, emergency transfer criteria shall be invoked.

d. When a facility has been loaded for four (4) continuous hours 

(or such longer period as may be established by the Rating 

Authority) above its normal rating, but at or below its LTE 

rating, corrective action, which may include voltage reduction

and/or load shedding, must be taken to return the facility to its 

normal rating within thirty (30) minutes.

Procedures shall be developed by the NYISO consistent with 

the NYISO tariffs that resolve transmission overloads caused 

by both internal and external events to the NYS Bulk Power 

System.

F-R2. Post-Contingency STE Rating Violations

If a transmission facility which constitutes a part of the NYS Bulk 

Power System is being operated under emergency transfer criteria

and becomes loaded to a level which would cause its 
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F. OPERATION DURING MAJOR EMERGENCIES (CONT’D.)

post-contingency loading to exceed its STE rating and corrective 

action could not be taken rapidly enough to meet the requirements 

of this policy once the contingency occurs, immediate corrective 

action which may include voltage reduction and load shedding, 

must be taken to reduce the loading such that sufficient time will 

be available to apply corrective action following the contingency.

F-R3. High or Low Voltage

Voltage control of the NYS Bulk Power System shall be coordinated 

to provide adequate voltage at all times to maintain power transfer 

capability.

When in a major emergency due to voltage problems, all

transmission owners shall be notified of the condition and direct 

the necessary corrective actions short of load shedding.

If, having taken the actions above, the actual voltage at any NYS 

Bulk Power System bus remains below its pre-contingency low 

limit for thirty (30) minutes or declines to a level below the 

midpoint between the pre- and post-contingency low limits and 

remains there for fifteen (15) minutes, the NYISO shall discuss the 

situation with the transmission owner(s) to determine if corrective 

action could be taken following a contingency to prevent a system 

voltage collapse. If it is anticipated that adequate time will not 

exist to prevent a voltage collapse following a contingency, the 

transmission owners shall be directed to take the necessary 

corrective action, including load shedding, to maintain a minimum 

voltage equal to the pre-contingency low limit. If the actual voltage 

at any NYS Bulk Power System bus declines below the 
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F. OPERATION DURING MAJOR EMERGENCIES (CONT’D.)

post-contingency low limit and is indicative of a system voltage 

collapse, the NYISO shall immediately order load shedding in the 

amount and at the locations deemed necessary to maintain a 

minimum voltage equal to the pre-contingency low limit.

F-R4. Post-Contingency Voltage

a. Less than 5%

If the post-contingency loading of an internal New York 

transfer interface or the post-contingency flow towards New 

York on an inter-control area interface exceeds the limits 

associated with a voltage collapse by less than 5%, measures 

shall be applied immediately to bring the loading to established 

limits within fifteen (15) minutes. If, after taking corrective 

action, loadings are not below the limit within fifteen (15) 

minutes, a major emergency shall be declared and corrective 

measures, which may include load relief, shall be initiated to 

bring the loading to established limits within fifteen (15) 

minutes. If loadings are not below the limit within thirty (30) 

minutes from the initial overload, load relief measures must be 

instituted.

b. More than 5%

If the post-contingency loading of an internal New York 

transfer interface or the post-contingency flow towards New 

York of an inter-control area interface exceeds the limits 

associated with a voltage collapse by 5% or more, a major 

emergency shall be declared immediately and corrective 

measures, which may include load relief, shall be initiated to 
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F. OPERATION DURING MAJOR EMERGENCIES (CONT’D.)

bring the loading to established limits. If loadings are not 

below 105% of the limit within fifteen (15) minutes from the 

initial overload, or below the limit within thirty (30) minutes 

from the initial overload, load relief measures must be 

instituted.

F-R5. Operating Reserve Deficiency

Emergency transfer criteria shall be invoked if necessary to provide 

transmission capability to deliver operating reserve to an area 

deficient in operating reserve. The NYISO shall notify all 

transmission owners that emergency transfer criteria have been 

invoked and transmission owners in the deficient area shall be 

prepared to return facilities to appropriate ratings within the 

prescribed time should such ratings be exceeded. If, after the 

above action, a shortage of ten (10) minute operating reserve or 

operating reserve still exists, the NYISO shall declare a major

emergency and shall direct that load relief procedures be 

implemented.

F-R6. Stability Limit Violation

a. Less than 5%

If the loading of an internal New York transfer interface or the 

power flow towards New York on an inter-control area

interface exceeds the system stability limit by less than 5%, 

measures shall be applied immediately to bring the loading to 

established limits within fifteen (15) minutes. If, after taking 

corrective action, loadings are not below the stability limit
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F. OPERATION DURING MAJOR EMERGENCIES (CONT’D.)

within fifteen (15) minutes, a major emergency shall be 

declared and corrective measures, which may include load 

relief, shall be initiated to bring the loading to established 

limits within fifteen (15) minutes. If loadings are not below the

stability limit within thirty (30) minutes from the initial 

overload, the transmission owners shall be ordered by the 

NYISO to institute load relief measures.

b. More than 5%

If the loading of an internal New York transfer interface or the 

power flow towards New York on an inter-control area

interface exceeds the system stability limit by 5% or more, a 

major emergency shall be declared immediately and corrective 

measures, which may include load relief, shall be initiated to 

bring the loading to established limits. If loadings are not 

below 105% of the stability limit within fifteen (15) minutes 

from the initial overload, or below the stability limit within 

thirty (30) minutes from the initial overload, load relief

measures must be instituted.

F-R7. Low Frequency

A sustained low frequency of 59.9 Hz is an indication of major 

load-generation imbalance in which case a major emergency shall 

be declared. During a major emergency resulting from a low 

frequency condition caused by load-generation imbalance within 

the NYCA, load shall be shed in accordance with a schedule 

previously determined.
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F. OPERATION DURING MAJOR EMERGENCIES (CONT’D.)

F-R8. Load Shedding Allocation

In the event that the frequency decline is so rapid as to prevent 

operator action, automatic facilities shall achieve load shedding

without regard for transmission loadings. Load shedding allocation 

procedures shall be developed which meet the requirements of the 

NPCC Underfrequency Load Shedding Guides.

The NYCA must be capable of shedding at least 50 percent of its 

load in ten (10) minutes or less. Insofar as practical, the first half 

of the load shed manually should not include that load which is 

part of any automatic load shedding plan.

If frequency is still declining below 58.5 Hz, all transmission 

systems shall take such steps as are necessary, including 

separating units to preserve generation, minimize damage and 

service interruption.

Measurements

F-M1. The NYISO shall maintain procedures and systems that ensure that 

appropriate actions are taken when frequency, reserves, thermal, 

voltage, and/or stability limits are violated. The NYISO must notify the 

NYSRC of any changes to these procedures and systems. (F-R1 

through F-R7)

F-M2. The NYISO shall report to the NYSRC on every instance of a major

emergency. Included in this report shall be a description of the 

incident, a summary of conditions that warranted the change to a 

major emergency state, a summary of actions taken, and the 
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F. OPERATION DURING MAJOR EMERGENCIES (CONT’D.)

effectiveness of those actions. A preliminary report shall be provided 

to the NYSRC within one week of the incident; and a final report, if 

requested by the NYSRC, shall be provided within one month 

following the incident. (F-R1 through F-R7)

F-M3. The NYISO shall maintain procedures and systems that ensure that 

sufficient load shedding capability exists for both manual and 

automatic response. The NYISO must notify the NYSRC of any 

changes to these procedures and systems. (F-R8)

F-M4. Each transmission owner shall report to the NYISO the amount of load

that is expected to be shed through automatic and manual load 

shedding, coincident with the peak load of its transmission district in 

accordance with NYISO procedures (see Measurement F-M3). The 

NYISO shall annually report compliance of this requirement to the 

NYSRC. (F-R8)

F-M5. Retired

F-M6. The NYISO shall institute a statewide voltage reduction test during the 

summer capability period of each year if statewide voltage reduction

has not been called for during the early portion of the summer. The

results of the test or actual voltage reduction shall be recorded and 

provided to the NYSRC every year. (F-R5)
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NYSRC Reliability Rules

G. SYSTEM RESTORATION

Introduction

The NYISO and market participants must ensure plans, procedures, and resources 

are available to restore the NYCA NYS Bulk Power to a normal condition in the 

event of a partial or system-wide shutdown. Accordingly, this Section sets forth 

Reliability Rules for the establishment and documentation of plans, procedures 

and resources required for the restoration of the NYCA system in the event NYCA 

experiences these types of partial or system-wide system shutdowns. 

Additionally, these rules establish requirements for the training of personnel in the 

execution of these plans and procedures. These Reliability Rules cover 

requirements for NYISO and transmission owner procedures, system blackstart 

capability, training, and restoration simulations.

Reliability Rules

G-R1. NYCA System Restoration Plan

A NYCA System Restoration Plan (NYCA SRP) shall be 

maintained to restore the NYCA system to a Normal Operating 

State in a safe, orderly and prompt manner following a major or 

total blackout. The NYCA SRP shall be comprised of a NYISO

system restoration plan and transmission owner system restoration 

plans.

G-R2. System Restoration Training and Simulation Programs

The NYISO and each transmission owner shall provide its 

personnel with a coordinated training program that will ensure 

effective implementation of the NYCA SRP and NYCA BCP as 

required in Reliability Rule G-R1.
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G. SYSTEM RESTORATION (CONT’D.)

Measurements

G-M1. The NYISO shall develop and maintain a NYCA System 

Restoration Plan (NYCA SRP) that will assure the prompt 

restoration of the NYCA system following a major or total 

blackout. The NYCA SRP shall define that system restoration take 

place at two integrated levels: restoration of the NYCA backbone 

system in accordance with a NYISO System Restoration Plan 

(NYISO SRP) and restoration of local areas in accordance with 

transmission owner system restoration plans (transmission owner 

SRPs). The NYCA SRP shall include the following minimum 

requirements:

1. Procedures for coordinating the NYISO SRP and the 

transmission owner SRPs.

2. Required actions to be included in each transmission owner’s 

restoration plan, consistent with NYISO procedures and 

NYSRC, NPCC, and NERC criteria.

3. Procedures for coordinating the SRPs of the NYISO and 

neighboring Reliability Coordinators, including restoration of 

interconnections.

4. Identification of blackstart facilities required for implementing 

the NYISO SRP, including the names, location, megawatt 

capabilities, megavar capabilities, and unit type.

5. Identification of blackstart facility test requirements to verify

that each blackstart facility in the NYISO SRP is capable of 

meeting the requirements of the NYISO SRP. These tests, at 
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G. SYSTEM RESTORATION (CONT’D.)

minimum, shall be conducted for each Capability Year and 

include those tests described in Table BS-1 of NPCC Directory 

#8, System Restoration. The NYISO shall determine the 

number of units within a blackstart facility that shall be tested 

annually, and the time within the Capability Year that testing 

shall be completed. The NYISO procedures shall indicate that 

with due regard for reliability considerations and subject to 

approval by the Transmission Owner and the NYISO, a test 

performed by blackstart facilities in the Transmission Owner’s 

SRP within one month beyond the Capability Year test period, 

or longer in force majeure cases, shall be considered a valid 

test for that Capability Year. On request by the NYSRC, the 

NYISO shall certify that reliability was considered when the 

NYISO and the Transmission Owner approved blackstart 

facility testing beyond the Capability Year.

6. Procedures requiring that each transmission owner identify 

blackstart resources that are necessary for implementing its 

SRP. These procedures shall also require transmission owners 

to identify the name, location, megawatt capacity, megavar 

capacity, and type of blackstart resource(s). The identity of 

transmission SRP blackstart facilities shall be made available 

to the NYISO and to affected transmission owners. In addition, 

NYISO procedures shall include a requirement that each 

Blackstart Provider annually provide a letter to the NYISO 

confirming that it identifies and maintains a list of critical 

components in its facilities (i.e., batteries, diesel back-up 

generators, inverters etc.) to verify the condition of these 

critical components in accordance with good industry practice.
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G. SYSTEM RESTORATION (CONT’D.)

7. Identification of the necessary operating instructions and 

procedures to cover loss of telecommunications channels 

during a system disturbance.

8. Identification of protocols for disseminating information to 

operating entities identified in the plan during a system 

disturbance.

9. Procedures for ensuring that the coordination of NYISO and 

transmission owner SRPs be demonstrated by drill or by 

simulation.

10. Procedures requiring transmission owners to notify the NYISO 

of any proposed changes to transmission owner SRP facilities 

or procedures that could effect the coordination of the NYISO 

and TO restoration plans at least two months prior to their 

implementation.

11. Procedures requiring that the NYISO and transmission owner 

SRPs be reviewed and updated annually and whenever changes 

are made in the NYS Power System. This review shall evaluate 

the impact of planned system expansion or reconfiguration on 

these SRPs, prior to implementation.

12. Identification of guidelines which provide the basis for 

alternative restoration actions if normal restoration procedures 

cannot be executed due to system conditions.

13. Procedures for coordinating annual updates to the NYISO SRP 

and restoration plans of neighboring Reliability Coordinators. 

(G-R1)
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G. SYSTEM RESTORATION (CONT’D.)

G-M2. Each transmission owner shall establish and maintain a restoration 

plan in accordance with the NYCA SRP, NYISO procedures, and 

Measurement G-M1. This restoration plan shall be coordinated 

with the restoration plans of other transmission owners and shall 

be part of the NYCA SRP. The transmission owner SRP shall

include procedures to identify blackstart resources that are 

necessary for implementing its SRP including testing requirements, 

in accordance with the NYCA SRP and NYISO procedures. 

Transmission owners shall conduct an annual review of their SRP. 

Transmission owners shall conduct annual training of their 

operating personnel on their SRP procedures, including the 

procedures for coordinating with the NYISO SRP. Each 

transmission owner shall report to the NYISO the completion of the 

annual training and review. (G-R1&2)

G-M3. Each Blackstart Provider shall develop appropriate test procedures 

in accordance with G-M2 requirements to ensure those blackstart 

facilities that are included in the transmission owner’s SRP are 

able to perform their intended functions. Each Blackstart Provider 

shall complete a successful test of the startup and operation of each

of its Blackstart Facilities included in the NYCA SRP for each 

Capability Year to demonstrate that its Blackstart Facilities can 

perform their intended functions in accordance with the procedures 

required in Measurement G-M1. The NYISO shall determine the

number of units within a blackstart facility that shall be tested 

annually, and the time within the Capability Year that testing shall 

be completed. 

With due regard for reliability considerations and subject to 

approval by the Transmission Owner and the NYISO, a test 

performed by blackstart facilities in the Transmission Owner’s 
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G. SYSTEM RESTORATION (CONT’D.)

SRP within one month beyond the Capability Year test period, or 

longer in force majeure cases, shall be considered a valid test for 

that Capability Year. Each Blackstart Provider shall provide 

documentation of these test results to the appropriate entity in 

accordance with NYISO and transmission owner procedures.

In addition, each Blackstart Provider shall annually provide a letter 

to the NYISO confirming that it identifies and maintains a list of 

critical components in its facilities (i.e., batteries, diesel back-up 

generators, inverters etc.) and performs tests to verify the condition 

of these critical components in accordance with good industry 

practice. Test results will be provided to the NYISO upon request. 

Blackstart Providers shall attend NYISO and transmission owner 

restoration training as required.

G-M4. The NYISO shall establish and maintain procedures for training 

NYISO and Market Participant operating personnel for the 

effective implementation of the NYCA SRP, in accordance with the 

following requirements:

1. NYISO procedures requiring coordinated training to be 

conducted at least annually by the NYISO and each 

transmission owner.

2. NYISO training procedures including restoration simulation 

exercises that include modeling of each transmission owner’s

SRP.

3. Conduct of annual simulations of full or partial system 

shutdowns and restoration, including the issuance of critique 

reports of their respective tests. 
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G. SYSTEM RESTORATION (CONT’D.)

4. NYISO training procedures requiring Blackstart Providers and 

other generator owners to participate in training sessions and 

exercises as appropriate.

5. Maintaining program records showing that operating personnel 

have been trained in the implementation of the NYCA SRP and 

participated in restoration exercises. These records shall be 

provided to the NYSRC upon request.

6. NYISO procedures for certifying that transmission owner

operating personnel have been trained on the transmission 

owner SRPs consistent with the requirements of NYISO SRP 

training procedures. The procedures shall require transmission 

owners to provide the NYISO restoration training program 

records upon request. (G-R2)
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NYSRC Reliability Rules

H. SYSTEM PROTECTION

Introduction

In general, the function of a protection system is to limit the severity and extent of 

system disturbances and possible damage to system equipment. Therefore, the 

reliability of the NYS Bulk Power System is impacted by the proper design, 

operation, maintenance, and application of protection systems in order to properly 

meet this function. Such protection systems include:

1. Underfrequency load shedding and equipment tripping

2. NYS Bulk Power System protection

3. Special protection systems

To meet these requirements, the Reliability Rules in this Section adopt the criteria 

for protection systems defined by NERC and NPCC Standards.

Reliability Rules

H-R1. Bulk Power System Protection

Protection systems shall be designed to limit the severity and extent 

of system disturbances and possible damages to system equipment 

in accordance with protection dependability and severity levels 

implicit in B-R1 through B-R4, and protection criteria established 

in NPCC “Bulk Power System Protection Criteria” (Directory #4).

H-R2. Bulk Power System Protection Maintenance

Comprehensive maintenance and testing programs for protection
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H. SYSTEM PROTECTION (CONT’D.)

equipment shall consist of verifying that protection equipment is 

capable of reliably and accurately performing their intended 

protection functions, in accordance with protection maintenance 

criteria established in NPCC “Maintenance Criteria for Bulk 

Power System Protection” (Directory #3).

Measurements

H-M1. The NYISO shall provide the NYSRC with compliance documentation 

and data in accordance with NPCC Directory #4, “Bulk Power System

Protection Criteria,” and requirements of the NPCC and NERC 

Compliance Programs, as requested. (H-R1)

H-M2. The NYISO shall provide the NYSRC with compliance documentation 

and data for meeting the requirements of the NYISO system protection 

maintenance procedure required by Measurement H-M3, as requested. 

(H-R2)

H-M3 The NYISO shall establish and maintain a procedure for monitoring 

compliance with the NPCC Directory #3, “Maintenance Criteria for 

Bulk Power System Protection,” as applied to the New York Control 

Area. This procedure shall include a description of how the system of 

compliance reporting is implemented within the NYISO. (H-R2)
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NYSRC Reliability Rules

I. LOCAL RELIABILITY RULES

Introduction

Local Reliability Rules have been adopted that apply to individual zones. These 

Reliability Rules are more stringent than other Reliability Rules because of the 

need to protect the reliable delivery of electricity for specific electric system 

characteristics and demographics relative to these zones. These conditions include 

unique circumstances and complexities related to the maintenance of reliable 

transmission service, and the dire consequences that would result from failure to 

provide uninterrupted service. Any constraints imposed by the more stringent 

criteria in these Local Reliability Rules shall be observed in daily operations. 

 

Certain of these Reliability Rules have been instituted as the result of NYS Public 

Service Commission orders or directives. The Local Reliability Rules apply to the 

New York City (I-R1 through I-R4) and Long Island (I-R5) zones.

Reliability Rules

I-R1. Operating Reserves/Unit Commitment (New York City)

Certain areas of the Con Edison system are designed and operated 

for the occurrence of a second contingency. Unit commitment is 

based on second contingency operation as well as consideration of 

the Storm Watch Procedure, loss of the six lines south of Millwood 

and the locational requirements for its operating reserves.

I-R2. Locational Reserves (New York City)

Sufficient ten (10) minute operating reserves shall be maintained in 

the New York City (NYC) zone as follows:
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I. LOCAL RELIABILITY RULES (CONT’D.)

a. The ten (10) minute operating reserve for NYCA shall be 

determined in accordance with Reliability Rules.

b. A percentage of the ten (10) minute NYCA operating reserves

equal to the ratio of the NYC zone peak load to the statewide 

peak load shall be required to be selected from resources

located within the NYC zone.

c. NYC zone ten (10) minute operating reserves shall be 

maintained at all levels of dispatch, except as necessary to 

alleviate emergency conditions.

I-R3. Loss of Generator Gas Supply (New York City)

The NYS Bulk Power System shall be operated so that the loss of a 

single gas facility does not result in the loss of electric load within 

the New York City zone.

I-R4. Thunderstorm Watch (New York City)

Con Edison will operate its system as if the first contingency has 

already occurred on its northern transmission system when 

thunderstorms are within one hour of the system or are actually 

being experienced.

I-R5. Loss of Generator Gas Supply (Long Island)

The NYS Bulk Power System shall be operated so that a loss of a 

single gas facility does not result in the uncontrolled loss of electric 

load within the Long Island zone.
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I. LOCAL RELIABILITY RULES (CONT’D.)

I-R3 & I-R5 Reliability Rule Applications

There are applications, approved by the NYISO for implementing this 

Reliability Rule, which specify minimum oil burn requirements for 

select generators in New York City and Long Island. 

From time to time, changes in system conditions and other 

circumstances may render existing applications inadequate, or may 

require alternate applications. Con Edison and LIPA, with NYISO

review and approval, shall determine whether revised or additional 

applications are necessary to meet this Reliability Rule and associated 

measurements. Any changes must be reviewed by the NYSRC for 

compliance with the Reliability Rules.

Measurements

I-M1. The NYISO shall document, maintain, and publish requirements for 

Con Edison to develop procedures for operating its system in 

accordance with I-R1, I-R3, and I-R4, including notification of the 

NYISO when actions are taken in accordance with these local 

reliability rules, and the reasons thereof. The NYISO shall review and 

approve Con Edison procedures and required studies, including any 

updates to such procedures and studies.

I-M2. The NYISO shall document, maintain, and publish requirements for 

LIPA to develop procedures for operating its system in accordance IR5, including notification of the NYISO when action is taken in 

accordance with this local reliability rule, and the reasons thereof. The 

NYISO shall review and approve LIPA procedures and required 

studies, including any updates to such procedures and studies.
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I. LOCAL RELIABILITY RULES (CONT’D.)

I-M3. The NYISO shall have in place procedures to ensure that sufficient ten 

(10) minute reserves are maintained in the NYC zone in accordance 

with I-R2.

I-M4. The NYISO shall apply I-R1 through I-R5 in:

a. the assessment of future transmission capability and analysis of 

transmission adequacy and security. 

b. the establishment of operating limits, assessment of operating 

adequacy, and operation on the NYS Bulk Power System.

I-M5. Con Edison shall have in place procedures for operating its system in 

accordance with I-R1, I-R3, and I-R4 and NYISO requirements (see IM1). These procedures must include notification to the NYISO when 

actions are taken in accordance with these local reliability rules, and 

the reasons thereof.

I-M6. LIPA shall have in place procedures for operating its system in 

accordance with I-R5 and NYISO requirements (see I-M2). These 

procedures must include notification to the NYISO when actions are 

taken in accordance with the local reliability rules, and the reasons 

thereof.

References

Reliability Rule 1 – PSC Directive, July 17, 1961

Reliability Rule 2 – PSC Order #27302

Reliability Rule 4 – PSC Order #27302
NYSRC Reliability Rules

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70

NYSRC Reliability Rules

J. NYISO CONTROL CENTER COMMUNICATIONS

Introduction

Adequate data and voice communication interfaces between the NYISO and 

Market Participants is essential for meeting the Reliability Rules and ensuring 

reliability. This Section covers NYISO procedures necessary for supporting the 

required NYISO/Market Participant communication facilities for meeting this 

objective.

Reliability Rules

J-R1. NYISO/Market Participant Communications

Procedures shall be developed to support communications 

between the NYISO and Market Participants during both normal 

and off-normal conditions. These procedures shall recognize the 

need for NYISO/Market Participant voice communications using 

emergency hot lines and "red phones" during off-normal 

conditions.

J-R2. NYISO Communications Under Emergency Conditions

Procedures shall be developed to support data and voice 

communications between the NYISO and Market Participants to 

ensure safe and reliable operations under the following emergency 

conditions:

a. Failure of data and/or voice communications between the 

NYISO and Market Participants.

b. Emergency transfer of control after evacuation of the NYISO

Power Control Center.
NYSRC Reliability Rules

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J. NYISO CONTROL CENTER COMMUNICATIONS (CONT’D.)

c. Continued operations from the NYISO Alternate Control 

Center.

The procedures shall identify how various systems are monitored 

for availability and include methods of tracking performance 

measures of system availability.

Measurements

J-M1. The NYISO shall develop the necessary procedures and other required 

documentation in compliance with J-R1 and J-R2, which shall be 

provided to the NYSRC on request.

J-M2. The NYISO shall prepare reports summarizing performance data of 

control center communication interfaces. These reports shall be 

provided to the NYSRC on request or when significant changes are 

made, and shall include a tracking basis of historical performance of 

voice and data communication equipment. (J-R2)

J-M3. The NYISO shall provide to the NYSRC within one month a report 

summarizing any loss of critical voice and/or data systems. The report 

shall describe the problem and its relationship to the control of the NYS 

Bulk Power System, the cause of the problem, the corrective action, 

and implementation schedule. (J-R2)
NYSRC Reliability Rules

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72

NYSRC Reliability Rules

K. RELIABILITY ASSESSMENT

Introduction

To ensure the reliability of the NYS Bulk Power System, the NYSRC, though the 

Reliability Compliance Monitoring Subcommittee (“RCMS”), reviews and 

assesses NYISO Planning and Operating Manuals to evaluate if they are in 

concert with the Reliability Rules.

In addition, the NYSRC, also through RCMS, reviews and assesses the overall 

reliability of the NYS Bulk Power System, both existing and planned, to be sure 

that it conforms to the Reliability Rules. 

To carry out this mission, RCMS must have sufficient data, reports, and other 

documentation from the NYISO, first, to ensure that NYISO planning analyses and 

operations meet the Reliability Rules, and second, to prepare and publish annual 

NYSRC assessments of the reliability of the existing and future NYCA generation

and transmission system. 

The NYISO must also assess the NYCA system within the context of 

interconnected networks. Therefore, the NYISO must coordinate its assessment 

efforts with neighboring control areas.
NYSRC Reliability Rules

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73

K. RELIABILITY ASSESSMENT (CONT’D.)

Reliability Rules

K-R1. NYISO Manuals

NYISO Planning and Operating Manuals shall conform to the 

Reliability Rules.

K-R2. Reliability Assessments

The overall reliability (adequacy and security) of the NYCA

interconnected NYS Bulk Power System shall be reviewed and 

assessed, both in real-time and as planned, to ensure that the 

NYISO and its Market Participants conform to the Reliability 

Rules.

K-R3. Extreme System Conditions Assessment

Events that have a low probability of occurrence, shall be assessed 

to determine, through transmission and resource adequacy 

assessments, the impact of these conditions on expected steadystate and dynamic system performance. These assessments shall 

provide an indication of system robustness or the extent of a 

widespread adverse system response. Transmission assessments 

shall consider the effect of design criteria contingencies specified 

in Table A on the NYS Bulk Power System. Analytical studies 

shall be conducted under the following Extreme System Condition 

events:

a. Peak load conditions resulting from extreme weather 

conditions with applicable rating of electrical elements.

b. Generating unit(s) fuel shortage, e.g., gas supply adequacy.

After due assessment of the above Extreme System Conditions, 

measures may be utilized, where appropriate, to mitigate the 
NYSRC Reliability Rules

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74

K. RELIABILITY ASSESSMENT (CONT’D.)

consequences that are indicated as a result of testing such system 

conditions.

Measurements

K-M1. The NYISO Planning and Operating Manuals shall be prepared by the 

NYISO in conformance with the Reliability Rules and submitted to the 

NYSRC for compliance review on request. (K-R1)

K-M2. The NYISO shall conduct, and provide to the NYSRC, the following 

reliability assessments:

a. A transmission review to demonstrate that the planned NYCA 

transmission system is in conformance with NYSRC Reliability 

Rules. Specifically, the transmission review shall incorporate 

assessments for documenting NYISO compliance with the 

following NYSRC measurements:

1. Measurement B-M1 – Thermal, voltage, stability, and short 

circuit assessments.

2. Measurement B-M2 – Extreme contingency assessment.

3. Measurement B-M3 – Compatibility with the NYCA system 

restoration plan.

4. Measurement I-M4 – Compatibility with NYSRC Local Rules.

5. Measurement K-M3 – Extreme system conditions.

The NYCA transmission review and its accompanying assessments 

shall cover the 4-6 year planning horizon and shall be prepared 

annually. The B-M1, B-M2 and K-M3 assessments shall cover 

system performance results of simulation tests and shall include all 

supporting documentation specified in NPCC Document B-4, 

Guidelines for NPCC Area Transmission Review, which shall be 
NYSRC Reliability Rules

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75

K. RELIABILITY ASSESSMENT (CONT’D.)

supplemented to include additional documentation that may be 

requested by the NYSRC.

b. A NYCA resource adequacy assessment for the next summer 

period and two years beyond, for demonstrating next capability 

period compliance with the NYSRC IRM requirement and NYISO

locational ICAP requirements, and prospective future compliance. 

The assessment shall include statewide and New York City and 

Long Island resource adequacy.

c. Interregional reliability assessments for ensuring that the NYCA

inter-control area and internal transmission system is developed on 

a coordinated basis. Reports on these assessments shall be 

provided as requested by the NYSRC. 

d. The NYISO shall provide a monthly operations report that 

provides data on the performance of the NYCA for the previous 

month, covering the following requirements: 

1. Occurrences of major emergency and alert states.

2. Summary of the NERC/NPCC Control Performance.

3. A list of NPCC Reportable Events.

4. Reserve requirements and actual reserves for the monthly peak 

load hour for all reserve categories (10 minute synchronized, 

10 minute non-synchronized, and 30 minute operating

reserves). The report shall distinguish between supply and 

demand side resources. (D-R1 through D-R3) 

5. The response of the system to activations of reserve, including: 

the number of occasions reserves were activated in the month, 

reasons for the reserve activations, number of occasions within 
NYSRC Reliability Rules

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76

K. RELIABILITY ASSESSMENT (CONT’D.)

the month in which the reserve activation did not result in an 

area control error (“ACE”) zero crossing, number of non-zero 

crossings associated with a unit loss, and number of non-zero 

crossings requiring another reserve activation. (D-R4)

6. Performance of the transmission system (E-R1 through E-R4), 

with respect to the number of events resulting in facilities 

exceeded system operating limits resulting in Alert States or 

Major Emergencies, including pre-contingency thermal and 

voltage limits, post-contingency thermal and voltage limits, and 

stability limits. 

7. A report of the number of more stringent events in which 

operating restrictions were imposed, resulting in an Alert or 

Major Emergency State due to severe weather conditions 

and/or severe solar magnetic disturbances. (E-R6, R7) 

8. Emergency actions initiated, including: emergency assistance 

from neighboring Control Areas, manual (local) voltage 

reductions, quick response (remote control) voltage reductions

(5 and 8%), voluntary load curtailment, public appeals, Special 

Case Resources, Emergency Demand Response Program, and 

load shedding. For each emergency action the report shall 

include: (a) the date of the emergency action; (b) the zone(s)

where the emergency action was implemented; (c) an estimate 

of the MW capacity addition or load relief achieved, by zone; 

and (d) the reason(s) why the emergency action was 

implemented. (F-R5) 

9. Other analyses and indices identified by the NYSRC Executive 

Committee for monitoring the security of the system.
NYSRC Reliability Rules

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77

K. RELIABILITY ASSESSMENT (CONT’D.)

e. Monthly operating reports covering occurrences of major

emergency and alert states, a summary of the NERC/NPCC 

Control Performance, a list of NPCC Reportable Events, and other 

indices identified by the NYSRC for monitoring the security of the 

system.

f. Special reliability assessments that may be requested by the 

NYSRC.

g. Copies of additional system reliability assessments requested by 

NPCC, but not covered above.

These assessments shall be coordinated with NERC and NPCC 

assessment requirements. (K-R2)

K-M3. The NYISO shall incorporate special simulation testing to assess the 

impact of Extreme System Conditions on the NYS Bulk Power System, 

and where appropriate, develop plans to mitigate the consequences that 

are indicated by these assessments. These tests shall show the impacts 

on steady state and dynamic performance of extreme condition events 

“a” and “b” specified in Reliability Rule K-R3. The scope of these 

studies shall meet NPCC guidelines for transmission and resource

adequacy assessments. The NYISO shall report the results of these 

assessments, including evaluations of mitigation measures for any 

cases that conclude serious consequences, as part of NYCA

transmission and resource adequacy assessments required by 

Measurement K-M2. (K-R3)
NYSRC Reliability Rules

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78

 III.

 NYSRC/NPCC/NERC RELIABILITY RULE CROSS-REFERENCE

Section NYSRC Rules NPCC Criteria NERC Standards

A-R1. Statewide Installed Reserve

Margin Requirement

Directory #1 ----

A-R2. LSE Installed Capacity 

Requirement ---- ----

A. Resource 

Adequacy

A-R3. External Installed Capacity 

(“External ICAP”) ---- ----

B-R1. Thermal Assessment Directory #1 TPL-001-0 to 003-0

B-R2. Voltage Assessment Directory #1 TPL-001-0 to 003-0

B-R3. Stability Assessment Directory #1 TPL-001-0 to 003-0

B-R4. Extreme Contingency 

Assessment Directory #1 TPL-004-0

B-R5. Restoration ---- ----

B-R6. List of NYS Bulk Power 

System Facilities A-10 ----

B. Transmission 

Capability –

Planning

B-R7. Fault Current Assessment Directory #1 ----

C-R1. Verification Testing of 

Resource Capacity

Directory #9

Directory #10

MOD-024-1, 025-1, 

TOP-002-2

C-R2. Resource Availability 

Requirements Directory #1 ----

C-R3. Load Forecasting Directory #1 MOD-016-0, 017-0

C-R4. System Data Requirements Directory #1 MOD-010-0, 011-0, 

012-0

C. Resource, System, 

& Demand Data 

Requirements

C-R5. Disturbance Recording Directory #1, A-15 PRC-002-1, 018-1

D-R1. Operating Resource 

Adequacy

Directory #1

Directory #5

BAL-002-0

D-R2. Minimum Operating Reserve 

Requirement

Directory #5 BAL-002-0

D-R3. Availability and Category Directory #5 BAL-002-0

D. Operating 

Reserves

D-R4. Restoration of Ten (10) 

Minute Reserve

Directory #5 BAL-002-0

E-R1 Thermal Assessment Directory #1 TOP-004-1,

FAC-011-1

E-R2 Voltage Assessment Directory #1 TOP-004-1,

FAC-011-1

E-R3. Stability Assessment Directory #1 TOP-004-1,

FAC-011-1

E-R4. Post-Contingency Operation Directory #1 IRO-004-0, 

TOP-004-0

E-R5. Outage Coordination Directory #1 TOP-003-0

E-R6. Operation During Impending 

Severe Weather

Directory #1

Directory #2 EOP-001-0

E-R7. Operation During a Severe 

Solar Magnetic Disturbance

Directory #1

Directory #2 EOP-001-0

E-R8. Fault Current Assessment Directory #1 ----

E-R9. Applications of the NYSRC 

Reliability Rules

---- ----

E. Transmission 

Capability -

Operating

E-R10. Exceptions to the NYSRC 

Reliability Rules

Directory #1 ----
NYSRC Reliability Rules

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79

 NYSRC/NPCC/NERC RELIABILITY RULE 

 CROSS-REFERENCE (CONT’D)

Section NYSRC Rules NPCC Criteria NERC Standards

F-R1. Transmission Thermal 

Overloads Directory #2 EOP-001-0, 002-2

F-R2. Post-Contingency STE 

Rating Violations Directory #2 EOP-001-0, 002-2

F-R3. High or Low Voltage Directory #2 EOP-001-0, 002-2

F-R4. Post-Contingency Voltage Directory #2 EOP-001-0, 002-2

F-R5. Operating Reserve 

Deficiency Directory #2 EOP-001-0, 002-2

F-R6. Stability Limit Violation Directory #2 EOP-001-0, 002-2

F-R7. Low Frequency Directory #2 EOP-001-0, 002-2

F. Operating During 

Major 

Emergencies

F-R8. Load Shedding Allocation Directory #2 EOP-003-1

G-R1. NYCA System Restoration 

Plan Directory #8 G. System EOP-005-2, 006-2Restoration

G-R2. System Restoration Training 

and Simulation Programs

Directory #8 EOP-005-2, 

PER-002-0

H-R1. Bulk Power System 

Protection Directory #1, 

Directory #4 

PRC-001-1, 003-1, 

004-1, 006-0, 007-0, 

009-0, 010-0

H. System Protection

H-R2. Bulk Power System 

Protection Maintenance Directory #3

PRC-005-1, 008-1, 

011-0, 012-0, 

PRC-017-0

I-R1. Operating Reserves/Unit 

Commitment (New York 

City)

---- ----

I-R2. Locational Reserves (New 

York City) ---- ----

I-R3. Loss of Generator Gas 

Supply (New York City) ---- ----

I-R4. Thunderstorm Watch (New 

York City) ---- ----

I. Local Reliability 

Rules

I-R5 Loss of Generator Gas 

Supply (Long Island) ---- ----

J-R1. NYISO/Market Participant 

Communications C-36 COM-001-1, 002-2

J. NYISO Control 

Center 

Communications J-R2. NYISO Communications 

Under Emergency 

Conditions

C-36 COM-001-1, 002-2

K-R1. NYISO Manuals ---- ----

K-R2. Reliability Assessments A-8, Directory #1 ----

K. Reliability 

Assessment

K-R3. Extreme System Conditions 

Assessment Directory #1 ----

The above NPCC Standards may be downloaded from: http://www.npcc.org

The above NERC Standards may be downloaded from: 

http://www.nerc.com/~filez/standards/Reliability_Standards.html
NYSRC Reliability Rules

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IV.

GLOSSARY
NYSRC Reliability Rules

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81

A. GLOSSARY INDEX

Glossary Index Introduction or 

Rule Section(s) Source of Definition

Applications of the Reliability Rules Introduction NYSRC 

Availability A, C NPCC 

Blackstart G NPCC 

Blackstart Facility G NYSRC

Blackstart Provider G NYSRC

Bulk Power System See NYS Bulk Power System

Capability Period A, K NYISO 

Capability Year G NYSRC

Capacity

Installed Capacity (“ICAP”)

Installed Capacity Requirement (“ICR”)

External Installed Capacity (“External ICAP”)

Net Dependable Capacity

Introduction, A, C, D, F, G

A, C

Introduction, A

A

C 

NPCC

NYSRC

NYSRC

NYSRC

NYSRC 

Contingency B, D, E, F, I NYSRC 

Contingency Reserve Adjustment Factor (CRA) D NYSRC

Control Area A, D, G, K NYSRC 

Demand Introduction, A, B, C NPCC 

Developer C NYSRC

Disturbance Introduction, B, E, H NPCC

Element Introduction, B, E, G NYSRC

Emergency

Major Emergency

Introduction, B, E, F, I, J

Introduction, F, K

NPCC 

NYSRC

Emergency Transfer Criteria E, F NYSRC 

Fault Introduction, B, E, F NPCC 

Fault Clearing

Delayed Fault Clearing

Normal Fault Clearing

B

B

B

NPCC

NPCC

NPCC 

Generation NYSRC Introduction, B, C, D, E, F, G, I, 

K

NPCC 

Interface B, F, J NPCC 

Load

Firm Load

Interruptible Load

Load Relief

Load Shedding

A, B, C, D, F, I, K

A, E

D

A, F

E, F, H

NPCC 

NYSRC

NYSRC

NYSRC 

NPCC (modified)

Load Serving Entities (“LSE”) A NYSRC 

Local Reliability Rules Introduction, E, I NYSRC 

Locational Installed Capacity Requirement 

(“Locational ICAP Requirement”)

A, K NYISO (modified)

Market Participant(s) Introduction, D, E, F, G, J, K NYSRC 

NYISO Secured Transmission System Introduction NYSRC 

New York Control Area (“NYCA”) Introduction, A, C, D, E, F, G, I, K NYISO 

New York Independent System Operator (“NYISO”) Introduction, A-K NYISO

New York State Bulk Power System (“NYS Bulk 

Power System”)

Introduction, B, C, E, F, H, I, K NYSRC 

New York State Power System (“NYS Power 

System”)

Introduction, B NYISO 

New York State Reliability Council, LLC (“NYSRC”) Introduction, A, B, C, D, E, F, H, 

J, K

NYSRC 

New York State Transmission System (“NYS 

Transmission System”)

Introduction, A, G NYISO 

Normal Transfer Criteria D NYSRC 
NYSRC Reliability Rules

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GLOSSARY INDEX (CONT’D.)

Glossary Index Introduction or 

Rule Section(s) Source of Definition

Normal Transfer Limit B NYSRC 

Obligation Procurement Period A NYISO 

Operating Limit E, I NPCC 

Operating Procedures Introduction, A NPCC

Protection

Protection Group

Protection System

E, H

E

B, H

NPCC 

NPCC

NPCC

Rating

Normal Rating

Long Time Emergency (“LTE”) Rating

Short Time Emergency (“STE”) Rating

B, E, F

B, E, F

B, E, F

B, E, F

NPCC 

NYSRC 

NYSRC 

NYSRC 

Rating Authority F NYSRC 

Reactive Power

Reactive Power Capacity

B, C

B, C

NYSRC

NYSRC

Reclosing

Delayed Reclosing

With Due Regard to Reclosing

B, E

B

NYSRC 

NPCC

Reliability

Adequacy

Security

Introduction, A, B, C, E, H, J, K

Introduction, A, D, I, K

Introduction, E, I, K

NPCC 

NPCC 

NPCC 

Reserve

Installed Reserve Margin (“IRM”)

Operating Reserve

Non-synchronized Ten (10) Minute 

Operating Reserve

Synchronized Operating Reserve

Ten (10) Minute Operating Reserve

Thirty (30) Minute Operating Reserve

D, F

A, C, K

D, E, F, I

D

D

B, D, E, F, I

D

NPCC 

NYSRC 

NYSRC

NYSRC 

NPCC (modified) 

NPCC

NYSRC

Resource NYSRC

Energy-Only Resources

A, C, D, E, G, K

C

NPCC 

NYISO 

Significant Adverse Impact Introduction NPCC 

Special Protection System (“SPS”) B, E, H NPCC

Stability B, E, F NPCC 

Stability Limit E, F NPCC (modified)

Steady State B NYSRC 

Suspect Data C NYSRC

System Operating States G NYSRC

Thermal Limit E, F NYSRC 

Transfer Capability A, E, F NYPP

Transmission District C, F NYISO (modified)

Transmission Owners Introduction, B, C, E, F, G NYSRC 

Uncontrolled Loss of Electric Load I NYSRC

Voltage Limit B, E NYSRC 

Voltage Reduction E, F NYSRC 

Zone A, C, F, I NYISO 
NYSRC Reliability Rules

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B. GLOSSARY

Applications of the Reliability Rules – New York transmission owner operating procedures that apply to 

very specific NYCA system locations or conditions which are applications of the NYS Reliability 

Rules, and require close coordination between the transmission owners and the NYISO. 

Availability – A measure of time a generating unit, transmission line, or other facility is capable of 

providing service, whether or not it actually is in service. Typically, this measure is expressed as a 

percent available for the period under consideration.

Blackstart - The ability of a generating unit or station to go from a shutdown condition to an operating 

condition and start delivering power without assistance from the electric system.

Blackstart Facility - A generating unit or units at a specific location: (i) that the NYISO or a TO has 

identified as a candidate to provide blackstart service; (ii) the owner of which has committed to the 

NYISO to provide such service; and (iii) that meets the requirements contained in the NYCA 

BCP.

Blackstart Provider - The owner of a Blackstart Facility.

Bulk Power System – See NYS Bulk Power System

Capability Period - Six (6) month periods which are established as follows: (1) from May 1 through 

October 31 of each year ("Summer Capability Period"); and (2) from November 1 of each year 

through April 30 of the following year ("Winter Capability Period"); or such other periods as may 

be determined by the Operating Committee of the NYISO. Each capability period shall consist of 

on-peak and off-peak periods.

Capability Year - A summer capability period followed by a winter capability period.

Capacity – The rated continuous load-carrying ability, expressed in megawatts (“MW”) or megavoltamperes (“MVA”) of generation, transmission or other electrical equipment.

Installed Capacity (“ICAP”) - Capacity of a facility accessible to the NYS Bulk Power System, that is 

capable of supplying and/or reducing the demand for energy in the NYCA for the purpose of 

ensuring that sufficient energy and capacity is available to meet the reliability rules. 

Installed Capacity Requirement (“ICR”) - The annual statewide requirement established by the 

NYSRC in order to ensure resource adequacy in the NYCA. 

External Installed Capacity ("External ICAP") – Installed capacity from resources located in control 

areas outside the NYCA that must meet certain NYISO requirements and criteria in order to 

qualify to supply New York LSEs. 

Net Dependable Capacity – The capability of electric generation resources that shall be the sustained 

maximum net output averaged over a period of time defined by the NYISO Installed Capacity 

Manual, Section 4.2.2, for the determination of net system capacity. The certified ability by 
NYSRC Reliability Rules

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84

equipment used for providing resource capacity shall be verified in accordance with the NYISO 

Installed Capacity Manual, Section 4.0. 

Contingency - An actual or potential unexpected failure or outage of a system component, such as a 

generator, transmission line, circuit breaker, switch, or other electrical element. A contingency 

also may include multiple components, which are related by situations leading to simultaneous 

component outages.

Contingency Reserve Adjustment Factor (CRA) - A factor used in determining the additional ten-minute 

reserve that the NYISO, not meeting the Disturbance Control Standard (DCS) for a given quarter 

must carry. It is calculated using the following formula:

CRAquarter=2 – {the average percentage DCS (expressed as a decimal) for the quarter of 

measurement}

Control Area - An electric system or systems, bounded by interconnection metering and telemetry, capable 

of controlling generation to maintain its interchange schedule with other control areas and

contributing to frequency regulation of the interconnection.

Demand – The rate at which energy must be generated or otherwise provided to supply an electric power 

system.

_____________________________________________________________________________________

Developer -- An Eligible Customer (as defined by the NYISO Tariff) developing a generation project larger 

than 10 megawatts, or a merchant transmission project, proposing to connect to the New York 

State Transmission System, in compliance with the NYISO Minimum Interconnection Standard

Disturbance – Severe oscillations or severe step changes of current, voltage and/or frequency usually 

caused by faults.

Element - Any electrical device with terminals which may be connected to other electrical devices; usually

limited to a generator, transformer, transmission circuit, circuit breaker, an high voltage direct 

current ("HVDC") pole, braking resistor, a series or shunt compensating device or bus section. A 

circuit breaker is understood to include its associated current transformer(s) and the bus section 

between the breaker bushing and its current transformer(s).

Emergency - Any abnormal system condition that requires automatic or immediate, manual action to 

prevent or limit loss of transmission facilities or generation resources that could adversely affect

the reliability of an electric system.

Major Emergency - A situation usually accompanied by abnormal frequency, abnormal voltage and/or 

equipment overloads which might seriously affect the reliability of the NYS Bulk Power System.

Emergency Transfer Criteria - It is intended that the NYS Bulk Power System be operated within 

normal transfer criteria at all times insofar as possible. However, in the event that adequate 

facilities are not available to supply firm load within normal transfer criteria, emergency transfer

criteria may be invoked. Under emergency transfer criteria, transfers may be increased up to, but 

not exceed, emergency ratings and limits as follows:

a. Pre-contingency line and equipment loadings may be operated up to LTE ratings for up to 

four (4) hours, provided the STE ratings are set appropriately. Otherwise, pre-contingency 
NYSRC Reliability Rules

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85

line and equipment loadings must be within normal ratings. Pre-contingency voltages and 

transmission interface flows must be within applicable pre-contingency voltage and stability 

limits. 

b. Post-contingency line and equipment loadings within STE ratings. Post-contingency voltages 

and transmission interface flows within applicable post-contingency voltage and stability 

limits.

Fault – An electrical short circuit.

Fault Clearing

Delayed Fault Clearing - Fault clearing consistent with correct operation of a breaker failure 

protection group and its associated breakers, or of a backup protection group with an intentional 

time delay. 

Normal Fault Clearing - Fault clearing consistent with correct operation of the protection system and 

with correct operation of all circuit breakers or other automatic switching devices intended to 

operate in conjunction with that protection system.

Generation – The process of producing electrical energy from other forms of energy; also, the amount of 

electric energy produced, usually expressed in kilowatt-hours (“kWh”) or megawatthours 

(“MWh”).

Interface – The specific set of transmission elements between two areas or between two areas comprising 

one or more electrical systems.

Load – The electric power used by devices connected to an electrical generating system. (IEEE Power 

Engineering)

Firm Load - The load of a market participant that is not contractually interruptible.

Interruptible Load – The load of a market participant that is contractually interruptible.

Load Relief - Load reduction accomplished by voltage reduction or load shedding or both. Voltage 

reduction and load shedding as defined in this document, are measures by order of the NYISO.

Load Shedding – The process of disconnecting (either manually or automatically) preselected 

customers’ load from a power system in response to an abnormal condition to maintain the 

integrity of the system and minimize overall customer outages. Load shedding is a measure 

undertaken by order of the NYISO. If ordered to shed load, transmission owner system dispatchers 

shall immediately comply with that order. Load shall normally all be shed within 5 minutes of the 

order.

Load Serving Entity (“LSE”) - In a wholesale competitive market, Central Hudson Gas & Electric 

Corporation, Consolidated Edison Company of New York, Inc., Long Island Power Authority 

(“LIPA”), New York State Electric & Gas Corporation, Niagara Mohawk Power Corporation, 

Orange & Rockland Utilities, Inc., and Rochester Gas and Electric Corporation, the current fortysix (46) members of the Municipal Electric Utilities Association of New York State, the City of 

Jamestown, Rural Electric Cooperatives, the New York Power Authority (“NYPA”), any of their 

successors, or any entity through regulatory requirement, tariff, or contractual obligation that is 
NYSRC Reliability Rules

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responsible for supplying energy, capacity and/or ancillary services to retail customers within New 

York State.

Local Reliability Rule – Reliability rules of the individual transmission owners which are based on meeting 

specific reliability concerns in limited areas of the NYS Bulk Power System, including but not 

limited to special conditions that apply to nuclear plants, such as NRC licensing requirements, and 

special requirements applicable to the New York City metropolitan area.

Locational Installed Capacity Requirement (“Locational ICAP Requirement”) – Due to transmission 

constraints, that portion of the NYCA ICAP requirement that must be electrically located within a 

zone, in order to ensure that sufficient energy and capacity are available in that zone and that 

NYSRC Reliability Rules are met. 

Locational ICAP requirements are currently applicable to two transmission constrained zones, 

New York City and Long Island, and are normally expressed as a percentage of each zone's annual 

peak load. 

Market Participant(s) - Entity or entities producing, transmitting, selling, and/or purchasing for resale 

capacity, energy, and ancillary services in the wholesale market, excluding the NYISO.

NYISO Secured Transmission System – Those specific facilities monitored and secured by the NYISO in 

the day-ahead unit commitment and real-time dispatch consistent with the reliability rules.

New York Control Area (“NYCA”) – The control area located within New York State which is under the 

control of the NYISO. See Control Area. 

New York Independent System Operator (“NYISO”) – The NYISO is a not-for-profit organization formed 

in 1998 as part of the restructuring of New York State's electric power industry. Its mission is to 

ensure the reliable, safe and efficient operation of the State's major transmission system and to 

administer an open, competitive and nondiscriminatory wholesale market for electricity in New 

York State.

New York State Bulk Power System (“NYS Bulk Power System”) – The portion of the bulk power system 

within the New York control area, generally comprising generating units 300 MW and larger, and 

generally comprising transmission facilities 230 kV and above. However, smaller generating units 

and lower voltage transmission facilities on which faults and disturbances can have a significant 

adverse impact outside of the local area are also part of the NYS Bulk Power System.

New York State Power System (“NYS Power System”) – All facilities of the New York State transmission

system, and all those generators located within New York State or outside New York State, some 

of which may be from time-to-time subject to operational control by the NYISO. 

New York State Reliability Council, LLC (“NYSRC”) - An organization established by agreement (the 

“NYSRC Agreement”) by and among Central Hudson Gas & Electric Corporation, Consolidated 

Edison Company of New York, Inc., LIPA, New York State Electric & Gas Corporation, Niagara 

Mohawk Power Corporation, Orange & Rockland Utilities, Inc., Rochester Gas and Electric 

Corporation, and the New York Power Authority, to promote and maintain the reliability of the 

Bulk Power System, and which provides for participation by Representatives of Transmission 

Owners, sellers in the wholesale electric market, large commercial and industrial consumers of 
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electricity in the NYCA, and municipal systems or cooperatively-owned systems in the NYCA, 

and by unaffiliated individuals.

New York State Transmission System (“NYS Transmission System”) – The entire New York State electric

transmission system, which includes (1) the transmission facilities under NYISO operational 

control; (2) the transmission facilities requiring NYISO notification; and (3) all remaining 

facilities within the NYCA. 

Normal Transfer Criteria - Under normal transfer criteria, adequate facilities are available to supply firm 

load with the bulk power transmission system within applicable normal ratings and limits as 

follows:

a. Pre-contingency line and equipment loadings within normal ratings. Pre-contingency 

voltages and transmission interface flows within applicable pre-contingency voltage and 

stability limits.

b. Post-contingency line and equipment loadings within applicable emergency (LTE or 

STE) ratings. Post-contingency voltages and transmission interface flows within 

applicable post-contingency voltage and stability limits.

All contingencies listed in Table A “Design Criteria Contingencies”, in the reliability rules apply 

under normal transfer criteria.

Normal Transfer Limit - The maximum allowable transfer is calculated based on thermal, voltage, and 

stability testing, considering contingencies, ratings, and limits specified for normal conditions. The 

normal transfer limit is the lowest limit based on the most restrictive of these three maximum 

allowable transfers.

Obligation Procurement Period – The period of time for which LSEs shall be required to satisfy their 

ICAP. Starting with the 2001-2002 winter capability period, obligation procurement periods shall 

be one calendar month in duration and shall begin on the first day of each calendar month.

Operating Limit –The maximum value of the most critical system operation parameter(s) which meet(s): 

(a) pre-contingency criteria as determined by equipment loading capability and acceptable voltage 

conditions; (b) stability criteria; (c) post-contingency loading and voltage criteria.

Operating Procedures – A set of policies, practices, or system adjustments that may be automatically or 

manually implemented by the system operator within a specified time frame to maintain the 

operational integrity of the interconnected electric systems.

Protection – The provisions for detecting power system faults or abnormal conditions and taking 

appropriate automatic corrective action.

Protection Group - A fully integrated assembly of protective relays and associated equipment that is 

designed to perform the specified protective functions for a power system element independent of 

other groups. 

Notes:

(a.) Variously identified as main protection, primary protection, breaker failure protection, backup protection, alternate protection, secondary protection, A protection, B protection, Group A, 

Group B, System 1 or System 2.
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Protection System –

(b) Pilot protection is considered to be one protection group.

Element Basis

One or more protection groups; including all equipment such as instrument transformers, station 

wiring, circuit breakers and associated trip/close modules, and communication facilities; installed 

at all terminals of a power system element to provide the complete protection of that element.

Terminal Basis

One or more protection groups, as above, installed at one terminal of a power system element, 

typically a transmission line.

Rating – The operational limits of an electric system, facility, or element under a set of specified 

conditions.

Normal Rating - The capacity rating of a transmission facility that may be carried through consecutive 

twenty- four (24) hour load cycles.

Long Time Emergency (“LTE”) Rating - The capacity rating of a transmission facility that can be 

carried through infrequent, non- consecutive four (4) hour periods.

Short Time Emergency (“STE”) Rating -The capacity rating of a transmission facility that may be 

carried during very infrequent contingencies of fifteen (15) minutes or less duration.

Rating Authority - The transmission owner who has the authority and responsibility for maintaining the 

correct dynamic rating for NYS Bulk Power System facilities in the NYISO Power Control Center 

computer. 

Reactive Power - The product of voltage and the quadrature component of alternating current. Reactive 

Power, is usually measured in mega-volt-amperes-reactive (“MVAr”).

Reactive Power Capacity - The certified ability of an electrical element to produce or absorb Reactive 

Power, as defined in the NYISO Services Manual, Section 3.5.2. 

Elements that produce reactive power such as capacitors and over-excited generators/synchronous 

condensers; and elements that absorb reactive power such as reactors, under-excited generators/ 

synchronous condensers and other inductive devices including the inductive portion of loads.

Reclosing

Delayed Reclosing - The reclosing of a circuit breaker after a time delay which is intentionally longer 

than that for high speed reclosing.

With Due Regard to Reclosing - This phrase means that before any manual system adjustments, 

recognition will be given to the type of reclosing (i.e., manual or automatic) and the kind of 

protection systems.

Reliability – The degree of performance of the bulk electric system that results in electricity being 

delivered to customers within accepted standards and in the amount desired. Reliability may be 

measured by the frequency, duration, and magnitude of adverse effects on the electric supply. 
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Electric system reliability can be addressed by considering two basic and functional aspects of the 

electric system – adequacy and security.

Adequacy – The ability of the electric system to supply the aggregate electrical demand and energy 

requirements of the customers at all times, taking into account scheduled and reasonably expected 

unscheduled outages of system elements.

Security – The ability of the electric system to withstand disturbances such as electric short circuits or 

unanticipated loss of system elements.

Reserve – In normal usage, reserve is the amount of capacity available in excess of the demand. 

Installed Reserve Margin (“IRM”) - That capacity above firm system demand required to provide for 

equipment forced and scheduled outages and transmission capability limitations.

Operating Reserve - Resource capacity that is available to supply energy, or curtailable load that is 

willing to stop using energy, in the event of emergency conditions or increased system load, and 

can do so within a specified time period.

Non-synchronized Ten (10) Minute Operating Reserve - The portion of ten (10) minute reserve 

consisting of resource capacity such as hydroelectric, pumped storage hydroelectric, and quick 

start combustion generation which can be synchronized and loaded to claimed capacity in ten (10) 

minutes or less, and interruptible load, including load reduction achieved by starting generation to

offset demand, which can be achieved in 10 minutes or less. Non-synchronized reserve must not 

exceed half of the ten (10) minute reserve.

Synchronized Operating Reserve -The portion of ten (10) minute reserve consisting of unused resource

capacity which is synchronized and ready to achieve claimed capacity or resource capacity which 

can be made available by curtailing pumping hydro units or canceling energy sales to other 

systems.

Ten (10) Minute Operating Reserve - The sum of synchronized and non-synchronized reserve capacity 

that is fully available in ten (10) minutes.

Thirty (30) Minute Operating Reserve - That portion of the NYISO’s operating reserve requirement 

that includes unused resource capacity which can and will be made fully available as promptly as 

possible, but in no more than thirty (30) minutes. It is the sum of synchronized and nonsynchronized reserve that can be utilized in thirty (30) minutes, excluding reserve that is counted 

as ten (10) minute reserve.

Resource - The total contributions provided by supply-side and demand-side facilities and/or actions. 

Supply-side facilities include utility and non-utility generation and purchases from neighboring 

systems. Demand-side facilities include measures for reducing load, such as conservation, demand 

management, and interruptible load.

Energy-only Resource – A resource that has a contractual obligation to provide energy and no 

obligation to provide ancillary services and capacity.

Significant Adverse Impact – With due regard for the maximum operating capability of the affected

systems, on or more of the following conditions arising from faults or disturbances, shall be 

deemed as having significant adverse impact:

a. system instability;

b. unacceptable system dynamic response or equipment tripping;

c. voltage levels in violation of applicable emergency limits;

d. loadings on transmission facilities in violation of applicable emergency limits;
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e. unacceptable loss of load.

Special Protection System (“SPS”) - A protection system designed to detect abnormal system conditions, 

and take corrective action other than the isolation of faulted elements. Such action may include 

changes in load, generation, or system configuration to maintain system stability, acceptable 

voltages or power flows. Automatic under frequency load shedding is not considered an SPS. 

Conventionally switched, locally controlled shunt devices are not SPSs.

Stability – The ability of an electric system to maintain a state of equilibrium during normal and abnormal 

system conditions or disturbances.

Stability Limit – The maximum power flow possible through a particular transmission element or interface, 

while maintaining stability in the entire system or the part of the system to which the stability limit 

refers.

Steady State – That point in time following a contingency after fast acting automatic equipment has 

operated. This equipment includes generation rejection, transmission cross-tripping (including 

capacitors and reactors), load rejections, generator voltage regulators, and static VAR 

compensators.

Suspect Data -- Data provided by Market Participants or Developers that does not meet the NYISO 

screening criteria for reasonableness and accuracy.

System Operating States - In addition to the Normal State, the four other operating states into which 

certain system conditions may cause a departure from the Normal State, are as follows: Warning, 

Alert, Major Emergency, and Restoration. These five operating states are defined in the “System 

Conditions of the NYS Bulk Power System”, Section V of the NYSRC Reliability Rules Manual. 

Examples of system conditions that could cause departure from the Normal State are: capacity 

deficiencies, energy deficiencies, loss of generation or transmission facilities, transmission facility 

overloads and high or low voltages, abnormal power system frequency, and environmental 

episodes. When the system enters an operating state other than the Normal State, the primary 

objective of the NYISO shall be to return the system to the Normal State as soon as possible.

Thermal Limit - The maximum power flow through a particular transmission element or interface, 

considering the application of thermal assessment criteria. 

Transfer Capability - The measure of the ability of interconnected electrical systems to reliably move or 

transfer power from one area to another over all transmission lines (or paths) between those areas 

under specified system conditions. 

Transmission District – The geographic area served by the NYCA investor-owned transmission owners 

and LIPA, as well as customers directly interconnected with the transmission facilities of NYPA. 

Transmission Owner - Those parties who own, control and operate facilities in New York State used for 

the transmission of electric energy in interstate commerce. Transmission owners are those who 
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own, individually or jointly, at least 100 circuit miles of 115 kV or above in New York State and 

have become a signatory to the TO/ISO Agreement. The Transmission owners currently consist of 

Central Hudson Gas and Electric Corporation, Consolidated Edison Company of New York, Inc., 

LIPA, New York State Electric & Gas Corporation, Niagara Mohawk Power Corporation, 

Rochester Gas and Electric Corporation, and the New York Power Authority.

Uncontrolled Loss of Electric Load - Loss of load resulting from voltage collapse, instability, separation of 

NYS power system elements, or cascading failure caused by a sudden disturbance to or 

unanticipated failure of NYS power system transmission elements, and which cannot be prevented 

by the Transmission Owner’s operator.

Voltage Limit – The maximum power flow through some particular point in the system considering the 

application of voltage assessment criteria.

Voltage Reduction - A means of achieving load reduction by reducing customer supply voltage, usually by 

3, 5, or 8 percent. If ordered by the NYISO to go into voltage reduction, transmission owner 

system dispatchers shall immediately comply with that order. Quick response voltage reduction 

shall normally be accomplished within ten (10) minutes of the order. See “Order” definition.

Zone - A defined portion of the NY control area that encompasses a set of load and generation buses. Each 

zone has an associated zonal price that is calculated as a weighted average price based on 

generator LBMPs and generator bus load distribution factors. A "zone" outside the NY control 

area is referred to as an external zone. Currently New York State is divided into eleven zones, 

corresponding to ten major transmission interfaces that can become congested
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V. SYSTEM CONDITIONS FOR OPERATING STATES OF THE NYS BULK POWER SYSTEM

MONITORED 

CRITERIA NORMAL WARNING ALERT MAJOR EMERGENCY RESTORATION

Transmission Facility

Pre-Contingency Flow

Flow is less than or equal to 

Normal rating

Flow is greater than Normal 

rating but less than or equal to 

LTE rating for not more than 30 

minutes.

OR

Emergency Transfer Criteria 

have been invoked but flow is 

less than or equal to Normal 

rating.

Emergency Transfer Criteria have 

been invoked 

AND

Flow is greater than Normal rating 

but less than or equal to LTE for 

not more than 4 hours

Flow is greater than LTE rating. 

OR

Flow is greater than Normal rating but 

less than or equal to LTE rating for 4 

hours.

Transmission Facility 

Post-contingency Flow for

loss of generation or single 

facility

Predicted flow is less than 

or equal to LTE rating

Predicted flow is greater than 

LTE rating but less than or equal 

to STE rating.

Predicted flow is greater than STE 

rating and there is sufficient time 

to take corrective action following 

contingency 

AND

Emergency Transfer Criteria have 

not been exceeded for more than 

30 minutes.

Predicted flow is greater than STE rating 

and there is not sufficient time to take 

corrective action following contingency.

OR

Emergency Transfer Criteria have been 

invoked and criteria have been exceeded 

for more than 30 minutes.

Transmission Facility 

Post-contingency Flow for 

loss of two adjacent circuits 

on the same structure 

Predicted flow is less than 

or equal to LTE rating

Emergency Transfer Criteria 

have been invoked. 

Post-contingency flow may 

exceed STE rating.

Emergency Transfer Criteria have 

been invoked. 

Post-contingency flow may exceed 

STE rating.

Emergency Transfer Criteria have been 

invoked.

Post-contingency flow may exceed STE 

rating.

Actual Voltage Voltage is within precontingency limits

Not Applicable Voltage is less than its precontingency low limit or greater 

than its pre-contingency high limit 

for less than 15 minutes. 

OR

Voltage is greater than its postcontingency high limit for less than 

10 minutes and is indicative of a 

system problem.

Voltage is less than its pre-contingency 

low limit or greater than its precontingency high limit for 15 minutes and 

is indicative of a system problem.

OR

Voltage is less than its pre-contingency 

low limit, is indicative of a system 

problem, and appropriate voltage control 

measures have already been taken. 

OR

Voltage is less than its post-contingency 

low limit and is indicative of a system 

problem.

OR

Voltage is greater than its postcontingency high limit for 10 minutes. 

Note: From NYISO Emergency Operations Manual, Exhibit A-1
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SYSTEM CONDITIONS FOR OPERATING STATES OF THE NYS BULK POWER SYSTEM (CONT’D.)

MONITORED 

CRITERIA NORMAL WARNING ALERT MAJOR EMERGENCY RESTORATION

Post-contingency voltage Post-contingency 

transmission facility flow is 

less than or equal to voltage 

collapse limit

Not Applicable Post-contingency transmission 

facility flow is greater than voltage 

collapse limit by less than 5% for 

less than 15 minutes.

Post-contingency transmission facility 

flow is greater than voltage collapse 

limits by less than or equal to 5% for 15 

minutes, or by more than 5%.

Reserve

10 minute Reserve

No 10-Minute Reserve 

deficiency

No 10-Minute Reserve 

deficiency, but only if using 

Emergency Transfer Criteria.

No 10-Minute Reserve deficiency, 

but only including quick response 

Voltage Reduction.

10 Minute Reserve deficiency exists 

after taking all actions defined in the 

NYISO Manual for Emergency 

Operations including purchase of 

operating capability.

Reserve

Operating Reserve 

No Operating Reserve 

deficiency

No Operating Reserve 

deficiency, but only if using 

Emergency Transfer Criteria.

No Operating Reserve deficiency, 

but only using Emergency Transfer 

Criteria.

Operating Reserve deficiency exists after 

taking all actions defined in the NYISO 

Manual for Emergency Operations 

including purchase of operating 

capability.

Stability Limits Transmission facility flow 

is less than or equal to 

stability limit

Not Applicable Transmission facility flow is 

greater than stability limit by less 

than 5% for less than 15 minutes.

Transmission facility flow is greater than 

stability limit by less than or equal to 5% 

for 15 minutes, or by more than 5%

Area Control Error (“ACE”) ACE is less than ±100 MW

OR

ACE is less than ±500 MW 

for less than 10 minutes

ACE is greater than ±100 MW 

but less than ± 500MW for more 

than 10 minutes.

ACE is greater than or equal to ± 

500 MW for less than 10 minutes.

ACE is greater than or equal to ± 500 

MW for more than 10 minutes.

Frequency Frequency is greater than or 

equal to 59.95 Hz and less 

than or equal to 60.05 Hz 

Not Applicable Frequency is greater than or equal 

to 60.05 Hz and is sustained at that 

level or continues to increase. 

OR

Frequency is less than or equal to 

59.95 Hz and is sustained at that 

level or continues to decline.

Frequency is greater than or equal to 

60.10 Hz and is sustained at that level or 

continues to increase.

OR

Frequency is less than or equal to 59.90 

Hz and is sustained at that level or 

continues to decline.

Communication, Computer, 

Control, & Indication 

Facilities 

Sufficient facilities to 

monitor system status

Not Applicable Partial failures impairing the 

capability of monitoring system 

status and the NYISO Shift 

Supervisor determines the power 

system is in jeopardy.

Insufficient communication facilities to 

monitor system status and the NYISO 

Shift Supervisor determines the power 

system is in serious jeopardy.

Note: From NYISO Emergency Operations Manual, Exhibit A-1
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SYSTEM CONDITIONS FOR OPERATING STATES OF THE NYS BULK POWER SYSTEM (CONT’D.)

MONITORED 

CRITERIA NORMAL WARNING ALERT MAJOR EMERGENCY RESTORATION

Neighboring Systems All neighboring systems 

operating under normal 

conditions

One or more neighboring 

systems not operating under 

normal conditions.

One or more neighboring systems 

in Voltage Reduction.

One or more neighboring systems in 

Voltage Reduction and requesting 

NYISO assistance via Voltage Reduction.

Separation within the New 

York Control Area

NO NO NO YES

An area within the NY 

Control Area is islanded, 

customer load is 

interrupted, or both, 

following a system 

disturbance affecting the 

NYS Power System.

Overgeneration

-- -- --

NYCA is overgenerating and corrective 

measures are not sufficient to reduce 

ACE to zero.

Other

-- --

A situation involving impending 

severe weather exists.

OR

A situation involving severe Solar 

Magnetic Disturbances exists.

--

Note: From NYISO Emergency Operations Manual, Exhibit A-1
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95

VI. EXCEPTIONS TO RELIABILITY RULES

REVISION 1 – MAY 11, 2010

Exception 

Reference 

No.

TO

 Exception 

Category Exception

NYSRC 

Reliability 

Rule

1 NYPA Run Back of 

Generators

Post Contingency Flow on Marcy-New Scotland

The post-contingency flow on the Marcy-New Scotland 18 line is allowed to exceed its 

LTE rating for the loss of the Edic-New Scotland 14 line by the amount of relief that can 

be obtained by tripping the Gilboa pumping load as a single corrective action. Also, the 

post-contingency flow on the Edic-New Scotland 14 line is allowed to exceed its LTE 

rating for either the loss of the Marcy-New Scotland 18 line alone, or the double-circuit 

loss of the Marcy-New Scotland 18 and Adirondack-Porter 12 lines, by the amount of 

relief that can be obtained by tripping the Gilboa pumping load as a single corrective 

action. 

Approved NYPP Operating Committee January 27, 1988.

E-R1

2 NG Applicable Rating Post Contingency Flow on Volney-Clay and Nine Mile-Clay

The post-contingency flow on the Volney-Clay #6 line and the 9 Mile-Clay #8 line is 

allowed to reach its STE rating for "normal" transfers. 

Approved NYPP Operating Committee October 25, 1979

E-R1

3 NG Applicable Rating 

Run Back of 

Generators

Post Contingency Flow on New Scotland-Leeds

The post-contingency flow on the NS-Leeds line is allowed to reach its STE rating for 

transfers to NE & SENY, with sufficient generation at Gilboa. 

Approved NYPP Operating Committee October 25, 1979.

E-R1

4 NG Monitoring Monitoring of Transmission Transformer

National Grid is fully responsible for monitoring all National Grid 345/115 kV, 345/230 kV, 

and 230/115 kV transformer overloads and contingency overloads. The NYISO notifies 

National Grid of any overloads and contingency overloads it detects, but does not invoke 

these limits unless requested to do so by National Grid. 

Approved NYPP Operating Committee October 25, 1979.

E-R1
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96

EXCEPTIONS TO RELIABILITY RULES (CONT’D.)

Exception 

Reference 

No.

TO

 Exception 

Category Exception

NYSRC 

Reliability 

Rule

5 NYPA Applicable Rating 

Run Back of 

Generators

Post Contingency Loading on Gilboa-Leeds

The post-contingency flow on the Gilboa-Leeds (GL-3) line is allowed to reach its STE 

rating with four generators on at Gilboa. 

Approved NYPP Operating Committee December 7, 1983.

E-R1

6

NYPA Special Protection 

System

Post Contingency Loading on L33P and L34P

The post-contingency flows on the L33P line and the L34P line are allowed to reach their 

STE ratings, provided there is sufficient generation rejection selected at the Saunders 

generating station in Ontario, or sufficient control remaining on the phase angle 

regulators to return the flows to LTE within 15 minutes. 

Approved NYPP Operating Committee December 14, 1994.

E-R1*

7 CE Run Back of 

Generators

Operational Control of Feeder 21192 for Loss of Feeders 21, 22, and A21191

The loss of the common tower carrying feeders 21 and 22 results in Arthur Kill generator 

3 feeding into the remaining 345/138 kV Fresh Kills transformer. To avoid overloading 

this transformer (Feeder 21192), the output of Arthur Kill 3 must be reduced so that the 

transformer is below its STE rating within 5 minutes and below its LTE rating within 10 

minutes, post contingency. 

Approved NYPP Operating Committee December 6, 1984.

E-R1

8 CE Special Protection 

System

Post Contingency Flow on Buchanan-Millwood W97 or W98

The post-contingency flow on line W97 for the loss of W98 may exceed its LTE rating up 

to its STE rating if the contingency loss of lines W98 and Y88 does not cause resultant 

flows on any other feeder to exceed Normal Transfer Criteria.

The post-contingency flow on line W98 for the loss of W97 may exceed its LTE rating up 

to its STE rating if the contingency loss of lines W97 and Y88 does not cause resultant 

flows on any other feeder to exceed Normal Transfer Criteria.

This exception does not apply if either W97, W98, Y88, Indian Point 3, or the overload 

relay system is out of service. 

Approved NYPP Operating Committee May 30, 1985.

E-R1*
NYSRC Reliability Rules

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97

EXCEPTIONS TO RELIABILITY RULES (CONT’D.)

Exception 

Reference 

No.

TO

 Exception 

Category Exception

NYSRC 

Reliability 

Rule

9

Rescinded

10/15/09

10 NYPA Special Protection 

System

Post Contingency Flow on Marcy AT-1 Transformer

The post-contingency flow on the Marcy AT-1 bank is allowed to exceed its STE rating 

for the loss of the Marcy AT-2 bank, provided that the overload relay protection on the 

AT-1 bank is in-service. 

Approved NYPP Operating Committee November 20, 1986.

E-R1*

11 NYPA Special Protection 

System

Post Contingency Flow on Plattsburgh-Vermont PV20 Line

The post-contingency flow on the Plattsburgh-Vermont PV20 tie-line is allowed to reach 

its STE rating so long as NYPA can ensure that the Overload Mitigation system is 

available on a manual or automatic basis to reduce the flow to below the LTE rating 

immediately following the actual occurrence of the contingency. 

Approved NYPP Operating Committee February 15, 1995.

E-R1*

12 NYPA Monitoring Post Contingency Flow on Marcy Transformer T2

The post-contingency flow on the Marcy Transformer T2 is allowed to exceed its LTE 

rating up to its STE rating following the loss of Marcy Transformer T1. 

Approved NYPP Operating Committee July 23, 1987.

E-R1
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98

EXCEPTIONS TO RELIABILITY RULES (CONT’D.)

Exception 

Reference 

No.

TO

 Exception 

Category Exception

NYSRC 

Reliability 

Rule

13 NYPA Run Back of 

Generators

Post Contingency Flows on Niagara Project Facilities

For the following Niagara Project facilities, the post-contingency flows are allowed to 

reach their STE ratings, if NYPA can ensure that sufficient generation can be reduced at 

Niagara to return the flows to less than their STE ratings within 5 minutes and to less 

than their LTE ratings within 10 minutes from the initial overload:

 Niagara Project transformers

 Lines connected directly to the Niagara Project

 

 Initially Approved by NYPP Operating Committee August 19, 1993.

 Revision Approved by NYSRC Executive Committee February12, 2010.

E-R1

14 CE Run Back of 

Generators

Operation of the Linden Cogen Plant for Transmission Outages on the Con Edison 

System

The post-contingency flow on feeder 42232, Gowanus-Greenwood 138kV, is allowed to 

exceed its STE rating following the simultaneous loss of feeders 21 and 22, GowanusFreshkills 345kV, which run on common towers. In the event that this contingency 

occurs, the Con Edison System Operator will immediately reduce the generation of the 

Linden Cogeneration Facility to alleviate the overload to less than its STE rating within 5 

minutes and to less than its LTE rating within 10 minutes from the initial overload. 

Approved NYPP Operating Committee January 29, 1997.

E-R1

15 NYSEG Voltage Control Post Contingency Voltage at Oakdale and Watercure

The post-contingency voltages at the Oakdale 345 kV bus, the Oakdale 230 kV bus, and 

Watercure 230 kV bus are allowed to fall below their respective post-contingency low 

voltage limits for either the simultaneous loss of the Oakdale-Lafayette 4-36 line and the 

Oakdale-Fraser 32 line, or the loss of one of these lines when the other line is already 

out of service. 

Approved NYPP Operating Committee May 16, 1991.

B-R2 & 

E-R2
NYSRC Reliability Rules

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99

EXCEPTIONS TO RELIABILITY RULES (CONT’D.)

Exception 

Reference 

No.

TO

 Exception 

Category Exception

NYSRC 

Reliability 

Rule

16 CE Monitoring East 13th Street and East River Load Pocket

Con Edison is responsible for operating for contingencies resulting from the loss of any 

East 13th Street 345/138 kV transformer, or the 345/69 kV transformer. These facilities 

provide radial support to the East 13th Street and East River load pocket and are not part 

of the bulk power system. 

Approved NYPP Operating Committee August 27, 1997.

E-R1

17 CE Special Protection 

System

Ramapo to Buchanan 345 kV Feeder Outages

During times when 345kV feeder Y94 - Ramapo to Buchanan is out of service, allow 

post-contingency loading for the loss of 345kV feeder W93 to exceed STE ratings on 

Transformer TA-5 and 138kV feeder 95891; and during times when 345kV feeder W93 –

Buchanan to Eastview is out of service, allow post-contingency loading when 345kV 

feeder Y94 is open ended at Ramapo to exceed STE ratings on Transformer TA-5 and 

138kV feeder 95891. If the stated event occurs during the specified outages, there is 

automatic overload protection installed to trip Buchanan 138kV breaker F7. 

Approved NYRSC Executive Committee May 9, 2003.

E-R1*

18 CE Applicable Rating 

Run Back of 

Generators

Eastview to Sprainbrook 345 kV Feeder W79 Outages

During an outage to either feeder Y94/95891 or feeder W79, post-contingency loadings 

shall be allowed to exceed the STE rating of Eastview transformer 2N for the loss of W79 

or Y94/95891, respectively, provided Indian Point #2 generation can and will back down 

post-contingency to reduce flows through transformer 2N within applicable limits, i.e., 

less than STE within 5 minutes and less than LTE within 10 minutes from the initial 

overload. 

Approved NYRSC Executive Committee May 10, 2002.

E-R1
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100

EXCEPTIONS TO RELIABILITY RULES (CONT’D.)

Exception 

Reference 

No.

TO

 Exception 

Category Exception

NYSRC 

Reliability 

Rule

19

Rescinded 

1/31/10

20 CE Applicable Rating PS&G Tie Feeders A2253, B3402, and C3403

Con Edison operates to post-contingency STE ratings on underground circuits based on 

the ability to reduce the loading to LTE ratings within 15 minutes and not exceed LTE 

ratings on any other facilities.

The following PSE&G tie feeders are operated to post-contingency LTE ratings:

 A2253 Linden-Goethals 230 kV

 B3402 Hudson-Farragut 345 kV

 C3403 Hudson-Farragut 345 kV

Approved NYRSC Executive Committee September 10, 1999

E-R1
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101

EXCEPTIONS TO RELIABILITY RULES (CONT’D.)

Exception 

Reference 

No.

TO

 Exception 

Category Exception

NYSRC 

Reliability 

Rule

21 CE Applicable Rating F30, F31, F36, F37, W64, 69, 70, W72, W75, W79, W80, W81, W82, W85, Y86, Y87, Y 

88, Y89, W90, W93, Y94, and W99 Above Normal Rating Operation

The following feeders on the Consolidated Edison System have STE ratings which are 

limited by disconnect or wavetrap restrictions and not by conductor sagging limitations. 

These feeders will be operated above Normal ratings and up to LTE ratings (for 4 hours) 

without changing their STE ratings:

F30 Pleasant Valley-Wood St. W80 Wood St.-Millwood West

F31 Pleasant Valley-Wood St. W81 Wood St.-Millwood West

F36 Pleasant Valley-East Fishkill W82 Millwood West-Eastview

F37 Pleasant Valley-East Fishkill W85 Millwood West-SprainBrook

W64 Eastview-SprainBrook Y86 Wood St.-Pleasantville

W65 Eastview-SprainBrook Y87 Wood St.-Pleasantville

69 Ramapo-South Mahwah Y88 Ladentown-Buchanan South

70 Ramapo-South Mahwah W89 Pleasantville-Dunwoodie

W72 Ramapo-Ladentown W90 Pleasantville-Dunwoodie

W79 Eastview-SprainBrook W99 Millwood West-Eastview

W93 Buchanan North-Eastview Y94 Ramapo-Buchanan NorthW75 

SprainBrook-Dunwoodie (Winter Rating Period Only)

Approved NYRSC Executive Committee September 10, 1999

E-R1

22 CE Applicable Rating W97 and W98 Above Normal Rating Operation

The following feeders on the Consolidated Edison System have overload relay 

protection. These feeders will be operated above Normal rating and up to LTE rating (for 

4 hours) without changing their STE ratings:

 W97 Buchanan South-Millwood West

 W98 Buchanan South-Millwood West

Approved NYRSC Executive Committee September 10, 1999

E-R1
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102

EXCEPTIONS TO RELIABILITY RULES (CONT’D.)

Exception 

Reference 

No.

TO

 Exception 

Category Exception

NYSRC 

Reliability 

Rule

23 NG Special Protection 

System Generation Rejection at Athens

When the Athens Generation Special Protection System is active, the post-contingency 

flows on the Leeds-Pleasant Valley 345kV line #92 or the Athens-Pleasant Valley 

345kV line # 91 are allowed to reach their STE ratings following the loss of the 

parallel #91 or #92 circuit respectively, provided that there is sufficient generation 

dispatched and selected for rejection/runback at the Athens generating station and 

that SPS rejection/runback actions take no more than three minutes in order to 

ensure that flows are returned to or below LTE ratings within 15 minutes.

Approved NYRSC Executive Committee March 9, 2007

E-R1*

* See NYSRC Reliability Rules Section E Introduction for note on SPSs.
NYSRC Reliability Rules

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103

VII. NYSRC PROCEDURE FOR NEW YORK CONTROL AREA 

TRANSMISSION REVIEWS

1. Introduction

 The NYSRC Reliability Rules require that the NYISO annually conduct four types of 

transmission assessments to ensure compliance with the Rules. These assessments 

shall be incorporated in a single report to be provided to the NYSRC Reliability 

Compliance Monitoring Subcommittee (RCMS). 

 A major assessment is the requirement for the NYISO to conduct annual reviews of 

the planed bulk power system of the New York Control Area (NYCA). The purpose 

of these reviews is to demonstrate that the planned NYCA bulk power transmission 

system is in conformance with the NYSRC Reliability Rules. It is also the intention of 

the NYSRC that conformance with the NYSRC Reliability Rules assure consistency 

with the NPCC Criteria and NERC Standards. By this review, the NYSRC will satisfy 

itself that the NYCA transmission, as planned, is in conformance with NYSRC 

Reliability Rules, and the NYISO is in full compliance with the rules.

 The purpose of the remaining three assessments is to ensure compatibility of the 

NYCA System Restoration Plan (SRP) and Local Rules with the planned transmission 

system, and to perform an analysis of Extreme System Conditions.

2. Relationship with NPCC Area Transmission Reviews

NPCC Directory #1, NPCC Design and Operation of the Bulk Power System, requires 

that each Planning Coordinator Area of NPCC prepare an annual assessment to 

determine whether its planned transmission system is in conformance with NPCC 

criteria. Procedures for conducting and reporting these transmission reviews are 

addressed in Appendix B of Directory #1. NYSRC Policy 7 adopts the NPCC 

assessment requirements as applied to NYCA, and supplements it with requirements 

for additional NYSRC assessments as required by the NYSRC Reliability Rules. 

Coordination with preparation of NPCC Transmission Review is addressed in this 

policy. It is the intention by the NYSRC that the NYISO not duplicate transmission 

system analyses and reporting already required by NPCC Directory #1.
NYSRC Reliability Rules

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104

3. Scope of Transmission Review

The transmission review shall incorporate NYISO assessments for documenting 

compliance with the following NYSRC measurements:

 Measurement B-M1 – This measurement requires thermal (Reliability Rule BR1), voltage (Reliability Rule B-R2), stability (Reliability Rule B-R3), and 

short circuit assessments (Reliability Rule B-R7). 

 Measurement B-M2 – This measurement requires the assessment of the risks 

and system performance resulting from extreme contingencies.

 Measurement B-M3 – Compatibility with the NYCA system restoration plan 

(Reliability Rule B-R5.)

 Measurement I-M4 – Compatibility with NYSRC Local Rules I-R1 to I-R5.

 Measurement K-M3 – Extreme system conditions (Reliability Rule K-R3).

The Measurements B-M1 and B-M2 transmission assessments shall cover the 4-6 year 

planning horizon shall be coordinated with NPCC and NERC assessment 

requirements. They shall cover system performance results of simulation tests and 

include all supporting documentation specified in NPCC Directory 1, Appendix B, 

Guidelines and Procedures for NPCC Area Transmission Reviews. 

 

4. Study Year

The NYCA transmission assessments for meeting Measurements B-M1 and B-M2 

shall generally cover the 4-6 year planning horizon, as required by NPCC (refer to 

NPCC Directory 1, Appendix B, section 3.0) 

5. Frequency of Reviews

The NYISO shall submit the NYCA transmission review annually to the Reliability 

Compliance (RCMS) Subcommittee. The schedule for this submission shall be 

coordinated with NPCC reliability assessment program due dates. The NYISO shall 
NYSRC Reliability Rules

January 7, 2011

105

notify RCMS of the NPCC due date of the next review as soon as it is announced by 

NPCC (refer to NPCC Directory 1, Appendix B, section 4.0). 

6. Format of Transmission Review Report

6.1. Thermal, Voltage, Stability, Short Circuit, and Extreme Contingency Assessments

These assessments may include one of the following types: a Comprehensive (or 

Full) Review, an Intermediate (or Partial) Review, or an Interim Review. The type of 

assessment required to be submitted by the NYISO in any given year is defined in 

NPCC Directory #1, Appendix B, Section 4.0. The types of assessment to be 

prepared by the NYISO for NYCA transmission review shall be consistent with 

these NPCC requirements.

The scope of thermal, voltage, stability, and short circuit assessments in the NYCA 

transmission review shall be consistent with the assessment presentation formats as 

defined in NPCC Directory #1, Appendix B, sections 5.0, 6.0, and 7.0. 

6.2. System Restoration Assessment

Measurement B-M3 requires the NYISO to evaluate the NYCA reliability impacts of 

system expansion plans on the NYCA system restoration plan (SRP). This 

assessment further requires that the NYISO identify modifications in the SRP 

required if such reliability impacts are found. The NYISO shall provide 

documentation or references for this assessment.

6.3. NYSRC Local Rules Assessment

Measurement I-M4 requires the NYISO to consider Local Rules I-R1 to I-R5 in its 

development of the base case of the transmission assessments described in section 

5.1. These local rules address NYC operating reserves and unit commitment, loss of 

generator gas supply in NYC and LI, NYC thunderstorm watch. The local rules 
NYSRC Reliability Rules

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106

assessment discussion shall describe how local rules are applied in the system model 

used for the transmission assessment. 

6.4. Extreme System Condition Assessments

As described in Reliability Rule K-R3 and Measurement K-M3, analytical studies 

shall be conducted under the following Extreme System Conditions:

a. A transmission assessment assuming extreme peak load conditions. 

b. Loss of generating unit fuel supply.

Supporting information for these assessments shall be provided. An evaluation 

of measures to mitigate the impact of Extreme System Contingency events, 

when serious consequences are determined, shall be provided. 

From time to time, the NYSRC may request the NYISO to conduct analyzes of 

other Extreme System Condition events.

Assessments for the above Extreme System Contingency events may not have 

to be provided when required by NPCC criteria. According, such NYISO 

assessments conducted for NPCC shall be referenced. 
NYSRC Reliability Rules

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107

VIII. RULE REVISION LOG

Rule/Measurement

Initially 

Adopted Revisions

A. Resource Adequacy

R1. NYCA Installed Reserve Margin Requirement 09/10/99 08/17/01, 12/10/04, 01/05/07

R2. LSE Installed Capacity Requirement 09/10/99 10/12/01

R3. External Installed Capacity (“External ICAP”) 08/17/01

M1 08/17/01

M2 08/17/01

M3 08/17/01

M4 08/17/01

B. Transmission Capability – Planning

R1. Thermal Assessment 09/10/99 03/14/03

R2. Voltage Assessment 09/10/99 04/13/07

R3. Stability Assessment 09/10/99 12/10/04, 4/13/07

R4. Extreme Contingency Assessment 09/10/99 07/13/07

R5. Restoration 09/10/99 04/13/07

R6. List of NYS Bulk Power System Facilities 06/14/02

R7. Fault Current Assessment 02/14/03

M1 10/12/01 03/14/03, 4/13/07

M2 10/12/01

M3 10/12/01 04/13/07

M4 06/14/02

C. Resource, System & Demand Data Requirements

R1. Verification Testing of Resource Capacity 09/10/99 08/17/01, 05/10/02

, 

03/14/03, 10/14/05

R2. Resource Availability Requirements 02/08/01 10/12/01, 10/09/09

R3. Load Forecasting 08/17/01

R4. System Data Requirements 02/14/03 7/9/10

R5. Disturbance Recording 07/12/05

M1 08/17/01 05/10/02*, 03/14/03, 

10/14/05, 1/9/09, 11/12/10

M2 08/17/01 10/14/05, 1/9/09

M3 08/17/01 10/14/05, 11/12/10

M4 10/12/01 10/09/09

M5 10/12/01 03/10/06, 10/09/09

M6 10/12/01 10/09/09

M7 08/17/01

M8 08/17/01

M9 02/14/03 12/09/05, 7/9/10

M10 02/14/03

M11 09/12/03 7/9/10

M12 07/12/05

M13 07/12/05

D. Operating Reserves

R1. Operating Resource Adequacy 09/10/99

R2. Minimum Operating Reserve Requirement 09/10/99 08/11/06

R3. Availability and Category 09/10/99 01/09/04, 11/13/07

R4. Restoration of Ten (10) Minute Reserve 09/10/99

M1 10/12/01 11/13/07, 12/04/09 Retired
NYSRC Reliability Rules

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108

RULE REVISION LOG

Rule/Measurement

Initially 

Adopted Revisions

M2 10/12/01

M3 10/12/01 12/04/09 Retired

E. Transmission Capability – Operating 

R1. Thermal Assessment 09/10/99

R2. Voltage Assessment 09/10/99 04/13/07

R3. Stability Assessment 09/10/99 04/13/07

R4. Post-Contingency Operation 09/10/99

R5. Outage Coordination 09/10/99

R6. Operation During Impending Severe Weather 09/10/99

R7. Operation During a Severe Solar Magnetic 

Disturbance 09/10/99

R8. Fault Current Assessment 09/12/03

R9. Application of the NYSRC Reliability Rules 03/10/06

R10. Exceptions to the NYSRC Reliability Rules 12/14/07

M1 10/12/01

M2 10/12/01 10/07/03, 12/04/09 Retired

M3 10/12/01

M4 10/12/01

M5 10/12/01 12/04/09 Retired

M6 09/12/03

M7 09/12/03 03/10/06

M8 03/10/06

M9 12/14/07 11/12/10

F. Operating During Major Emergencies

R1. Transmission Thermal Overloads 09/10/99

R2. Post-Contingency STE Rating Violations 09/10/99

R3. High or Low Voltage 09/10/99

R4. Post-Contingency Voltage 09/10/99

R5. Operating Reserve Deficiency 09/10/99

R6. Stability Limit Violation 09/10/99

R7. Low Frequency 09/10/99

R8. Load Shedding Allocation 09/10/99

M1 10/12/01

M2 10/12/01 10/14/05

M3 10/12/01

M4 10/12/01 03/10/06

M5 10/07/03 12/04/09 Retired

M6 04/15/05

G. System Restoration

R1. NYCA System Restoration Plan 09/10/99 09/14/01, 03/10/06, 8/14/09

R2. NYCA Blackstart Capability Plan 09/10/99 09/14/01, 03/10/06, 8/14/09

R3.

R2. System Restoration Training and Simulation 

Programs

09/10/99 09/14/01, 03/10/06, 8/14/09

M1 09/14/01 01/09/04, 03/10/06,

 07/13/07, 8/14/09, 1/07/11

M2 09/14/01 03/10/06, 05/09/08, 8/14/09

M3 09/14/01 03/10/06, 8/14/09, 1/07/11

M4 09/14/01 03/10/06, 05/09/08, 8/14/09
NYSRC Reliability Rules

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109

Rule/Measurement

Initially 

Adopted Revisions

H. System Protection

R1. Bulk Power System Protection 09/10/99 08/17/01

R2. Bulk Power System Protection Maintenance 09/10/99 08/17/01

M1 08/17/01 01/03/04 

M2 08/17/01 06/14/02; 05/09/03, 10/07/03

M3 05/09/03 Replaced by New H-M2, 

10/07/03

I. Local Reliability Rules 

R1. Operating Reserves/Unit Commitment 

(New York City) 09/10/99

R2. Locational Reserves (New York City) 09/10/99 09/14/01, 11/13/07

R3. Loss of Generator Gas Supply (NYC & LI) 09/10/99 04/11/02, 07/13/07

R4. Thunderstorm Watch (New York City) 09/10/99

 R5. Loss of Generator Gas Supply (Long Island) 07/13/07

M1 12/14/01

M2 12/14/01 03/14/03, 05/09/03, 07/13/07

M3 12/14/01 05/09/03

M4 12/14/01 07/13/07

M5 12/14/01

M6 12/14/01 07/13/07

J. NYISO Control Center Communications

R1. NYISO/Market Participant Communications 09/10/99

R2. NYISO Communications Under Emergency

Conditions 09/10/99 12/10/04

M1 10/12/01

M2 11/12/02 12/10/04

M3 12/10/04

K. Reliability Assessment

R1. NYISO Manuals 08/17/01

R2. Reliability Assessments 08/17/01

R3. Extreme System Conditions Assessment 07/12/05

M1 08/17/01

M2 08/17/01 10/14/05, 1/9/09, 12/4/09

M3 06/10/05

Expedited Reliability Rule and Measurement modification.
NYSRC Reliability Rules

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110

NYSRC MANUAL VERSION HISTORY

RELIABILITY RULES MANUAL

Version Date Changes

1 2/1/02 Initial Rev 2 version

2 4/11/02 Table of Contents; Rules I-R3 & 5 replaced by new I-R3 (PRR 

#47)

3 5/10/02 Expedited rule modification to C-R1 and C-M1 (PRR #50) ; 

Revision to rule exception #19 (PRR #49)

4 6/14/02 Table of Contents; New Rule B-R6 and Measurement B-M4 

(PRR #48); Revision to Measurement H-M2; Update of 

NYSRC/NPCC/NERC Reliability Rule Cross-Reference

5 11/12/02 New measurement J-M2 (PRR #53); Glossary: Revised definition 

of Reactive Power (PRR #51)

6 3/14/03 Table of Contents; New Rule B-R7 and modified Measurement 

B-M1 (PRR #29); Modified Rule C- R1 and Measurement C-M1 

(PRR #50); New Rule C-R4 and Measurements C-M9&10 (PRR 

#58); Update of NYSRC/NPCC/NERC Reliability Rule CrossReference; Revised Glossary definition of Dependable Maximum 

Net Capacity

7 5/9/03 Revised Measurement H-M2 and new Measurement H-M3 (PRR 

#55); Revised Exception #18 (PRR #56)

8 10/7/03 New Rule E-R8 and related Measurements E-M6 & E-M7 

(PRR #57); New Measurement C-M11 (PRR #63); Revised 

Measurement E-M2 & New Measurement F-M5 (PRR #64); 

Updated Reliability Rules Section B & E Guidelines

9 1/9/04 Revised Rule D-R3 (PRR #65); Revised Measurement G-M1 

(PRR #66); New Glossary definition of Interruptible Load

10 12/17/04 Revised Rule J-R2 & Measurement J-M2 and New Measurement 

J-M3 (PRR #67); Revised Rule B-R3 (PRR #70); Revised Rules 

Section B Tables A & B (PRR #71); Revised Rule A-R1 (PRR 

#75); Revised Rules Section B Introduction

11 3/4/05 Revisions to the Introduction and Glossary Index

12 5/2/05 New Measurement F-M6 (PRR #77); Revised Section III to 

account for new NERC Version 0 Standards

13 8/12/05 New Rule K-R3 & Measurement K-M3 (PRR #72); New Rule CR5 & Measurements C-M12 and C-M13 (PRR #69); Revised 

Section III to include new rules

14 10/14/05 Revised Rule C-R1 and Measurements C-M1, C-M2, and C-M3 

(PRR #73); Revised Measurement F-M2, and removal of 

Measurement K-M2e and renumbering of F-M2f&g (PRR #78)

15 12/9/05 Revisions to the Introduction; Revised Measurements C-M9 and 

C-M11 (PRR #74)
NYSRC Reliability Rules

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Version Date Changes

16 3/10/06 Revised Table of Contents; Revised Rules G-R1, G-R2 and G-R3 

and Measurements G-M1, G-M2, G-M3, and G-M4 (PRR #76); 

New Rule E-R9 and New Measurement E-M8 (PRR #79); 

Revised Measurement C-M5 (PRR #80); Revised Measurement 

E-M7 (PRR #81); Revised Measurement F-M4 (PRR #82); 

Revised Measurements I-M5 and I-M6 (PRR #83); Revised 

Section III to include new rule; new glossary definitions of 

Blackstart Facility, Blackstart Provider, and System Operating 

States

17 8/11/06 Revised Rule D-R2 and new glossary definition of Contingency 

Reserve Adjustment Factor (PRR #85)

18 1/5/07 Revised Manual Introduction; Revised Introductions to 

Reliability Rules Sections B, C, E, F, G, and I; Revised Rule AR1 (PRR #89)

19 4/13/07 Revised Rules B-R2, B-R3, E-R2, and E-R3 and Measurement BM1 (PRR #86); Revised B-R5 and B-M3 (PRR #90); Revised

I-R3 Reliability Rule Application

20 07/13/07 Revised Table of Contents; Revised Rule I-R3 and new Rule IR5, Revised Measurements I-M2, I-M4 and I-M6, new glossary 

definition of Uncontrolled Loss of Electric Load (PRR #88); 

Revised Rule B-R4 (PRR #91); Revised Measurements G-M1.2 

and G-M1.10 (PRR #92).

21 12/14/07 Revised Table of Contents; Revised Introduction to Rule Section 

D; Revised Rules D-R3 and I-R2, revised Measurement D-M1, 

revised glossary definitions of Operating Reserve, NonSynchronized Reserve, Synchronized Reserve, and 30-Minute 

Reserve (PRR #93); New Rule E-R10 and new Measurement EM9 (PRR #94); Revised Section III to include new Rule E-R10; 

Revised Section VI, Exceptions to NYSRC Reliability Rules.

22 5/9/08 Revised Manual Introduction; Revised Measurements G-M2 and 

G-M4 (PRR #95); Removed References subsection from each 

Reliability Rule section; Revised Part III, NYSRC/NPCC/NERC 

Reliability Rules Cross-Reference to account for new NPCC and 

NERC Standards.

23 1/9/09 Revised Measurements C-M1 and C-M2 (PRR #96); Revised 

Measurement K-M2a (PRR #98); Revised Section I Introduction; 

Moved I-R3 and I-R5 Applications to follow Rule I-R5; Revised 

Part III, NYSRC/NPCC/NERC Reliability Rules CrossReference.

24 8/14/09 Revised Rules G-R1, removed G-R2, revised G-R3and renumber 

to G-R2, revised G-M1, G-M2 and G-M3 (PRR #99); Revised 

Part III, Cross-Reference Section to remove G-R2.

25 10/9/09 Revised Rule C-R2, revised Measurements C-M4, C-M5, and CM6, new Glossary definition of Suspect Data (PRR #101).
NYSRC Reliability Rules

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112

Version Date Changes

26 12/4/09 Revised Measurement K-M2d, retirement of Measurements 

D-M1, D-M3, E-M2, E-M5, and F-M5 (PRR #102); Revised Part 

III, NYSRC/NPCC/NERC Reliability Rules Cross-Reference to 

account for new NPCC directories.

27 7/9/10 Revised Rule C-R4, revised Measurements C-M9 and C-M11, 

new Glossary definition of Developer, revised Glossary definition 

of Suspect Data (PRR 103). 

28 11/12/10 Revised Measurements C-M1 and C-M3 (PRR #104); Revised 

Measurement E-M9 (PRR #105,

29 1/7/11 Revised Measurements G-M1 and G-M3, new Glossary definition 

of Capability Year and revised definition of Capability Period

(PRR #106); Updated Section III – Reliability Rule CrossReference, New Section VII, “NYSRC Procedure for NYCA 

Transmission Reviews.”