Reliability Standard PRC-005-3

Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

A. Introduction
1.

Title:

Protection System and Automatic Reclosing Maintenance

2.

Number:

PRC-005-3

3.

Purpose:
To document and implement programs for the maintenance of all Protection
Systems and Automatic Reclosing affecting the reliability of the Bulk Electric System (BES)
so that they are kept in working order.

4.

Applicability:

4.1. Functional Entities:
4.1.1

Transmission Owner

4.1.2

Generator Owner

4.1.3

Distribution Provider

4.2. Facilities:
4.2.1

Protection Systems that are installed for the purpose of detecting Faults on BES
Elements (lines, buses, transformers, etc.)

4.2.2

Protection Systems used for underfrequency load-shedding systems installed per
ERO underfrequency load-shedding requirements.

4.2.3

Protection Systems used for undervoltage load-shedding systems installed to
prevent system voltage collapse or voltage instability for BES reliability.

4.2.4

Protection Systems installed as a Special Protection System (SPS) for BES
reliability.

4.2.5

Protection Systems for generator Facilities that are part of the BES, including:

4.2.5.1 Protection Systems that act to trip the generator either directly or via lockout
or auxiliary tripping relays.
4.2.5.2 Protection Systems for generator step-up transformers for generators that are
part of the BES.
4.2.5.3 Protection Systems for transformers connecting aggregated generation,
where the aggregated generation is part of the BES (e.g., transformers
connecting facilities such as wind-farms to the BES).
4.2.5.4 Protection Systems for station service or excitation transformers connected to
the generator bus of generators which are part of the BES, that act to trip the
generator either directly or via lockout or tripping auxiliary relays.
4.2.6

Automatic Reclosing1, including:

4.2.6.1 Automatic Reclosing applied on the terminals of Elements connected to the
BES bus located at generating plant substations where the total installed
1

Automatic Reclosing addressed in Section 4.2.6.1 and 4.2.6.2 may be excluded if the equipment owner can
demonstrate that a close-in three-phase fault present for twice the normal clearing time (capturing a minimum tripclose-trip time delay) does not result in a total loss of gross generation in the Interconnection exceeding the gross
capacity of the largest BES generating unit within the Balancing Authority Area where the Automatic Reclosing is
applied.

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Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance
gross generating plant capacity is greater than the gross capacity of the
largest BES generating unit within the Balancing Authority Area.
4.2.6.2 Automatic Reclosing applied on the terminals of all BES Elements at
substations one bus away from generating plants specified in Section 4.2.6.1
when the substation is less than 10 circuit-miles from the generating plant
substation.
4.2.6.3 Automatic Reclosing applied as an integral part of an SPS specified in
Section 4.2.4.

5.

Effective Date: See Implementation Plan

6.

Definitions Used in this Standard: The following terms are defined for use only within
PRC-005-3, and should remain with the standard upon approval rather than being moved to the
Glossary of Terms.
Automatic Reclosing – Includes the following Components:
 Reclosing relay
 Control circuitry associated with the reclosing relay.
Unresolved Maintenance Issue – A deficiency identified during a maintenance activity that
causes the component to not meet the intended performance, cannot be corrected during the
maintenance interval, and requires follow-up corrective action.
Segment – Components of a consistent design standard, or a particular model or type from a
single manufacturer that typically share other common elements. Consistent performance is
expected across the entire population of a Segment. A Segment must contain at least sixty
(60) individual Components.
Component Type – Either any one of the five specific elements of the Protection System
definition or any one of the two specific elements of the Automatic Reclosing definition.
Component – A Component is any individual discrete piece of equipment included in a
Protection System or in Automatic Reclosing, including but not limited to a protective relay,
reclosing relay, or current sensing device. The designation of what constitutes a control circuit
Component is dependent upon how an entity performs and tracks the testing of the control
circuitry. Some entities test their control circuits on a breaker basis whereas others test their
circuitry on a local zone of protection basis. Thus, entities are allowed the latitude to
designate their own definitions of control circuit Components. Another example of where the
entity has some discretion on determining what constitutes a single Component is the voltage
and current sensing devices, where the entity may choose either to designate a full three-phase
set of such devices or a single device as a single Component.
Countable Event – A failure of a Component requiring repair or replacement, any condition
discovered during the maintenance activities in Tables 1-1 through 1-5, Table 3, and Tables 41 through 4-2 which requires corrective action or a Protection System Misoperation attributed
to hardware failure or calibration failure. Misoperations due to product design errors, software
errors, relay settings different from specified settings, Protection System Component or
Automatic Reclosing configuration or application errors are not included in Countable Events.

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Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

B. Requirements
R1. Each Transmission Owner, Generator Owner, and Distribution Provider shall establish a
Protection System Maintenance Program (PSMP) for its Protection Systems and Automatic
Reclosing identified in Facilities Section 4.2. [Violation Risk Factor: Medium] [Time
Horizon: Operations Planning]
The PSMP shall:

1.1. Identify which maintenance method (time-based, performance-based per PRC-005
Attachment A, or a combination) is used to address each Protection System and
Automatic Reclosing Component Type. All batteries associated with the station dc
supply Component Type of a Protection System shall be included in a time-based
program as described in Table 1-4 and Table 3.

1.2. Include the applicable monitored Component attributes applied to each Protection System
and Automatic Reclosing Component Type consistent with the maintenance intervals
specified in Tables 1-1 through 1-5, Table 2, Table 3, and Table 4-1 through 4-2 where
monitoring is used to extend the maintenance intervals beyond those specified for
unmonitored Protection System and Automatic Reclosing Components.

R2. Each Transmission Owner, Generator Owner, and Distribution Provider that uses performancebased maintenance intervals in its PSMP shall follow the procedure established in PRC-005
Attachment A to establish and maintain its performance-based intervals. [Violation Risk
Factor: Medium] [Time Horizon: Operations Planning]

R3. Each Transmission Owner, Generator Owner, and Distribution Provider that utilizes timebased maintenance program(s) shall maintain its Protection System and Automatic Reclosing
Components that are included within the time-based maintenance program in accordance with
the minimum maintenance activities and maximum maintenance intervals prescribed within
Tables 1-1 through 1-5, Table 2, Table 3, and Table 4-1 through 4-2. [Violation Risk Factor:
High] [Time Horizon: Operations Planning]

R4. Each Transmission Owner, Generator Owner, and Distribution Provider that utilizes
performance-based maintenance program(s) in accordance with Requirement R2 shall
implement and follow its PSMP for its Protection System and Automatic Reclosing
Components that are included within the performance-based program(s). [Violation Risk
Factor: High] [Time Horizon: Operations Planning]

R5. Each Transmission Owner, Generator Owner, and Distribution Provider shall demonstrate
efforts to correct identified Unresolved Maintenance Issues. [Violation Risk Factor: Medium]
[Time Horizon: Operations Planning]

C. Measures
M1. Each Transmission Owner, Generator Owner and Distribution Provider shall have a
documented Protection System Maintenance Program in accordance with Requirement R1.
For each Protection System and Automatic Reclosing Component Type, the documentation
shall include the type of maintenance method applied (time-based, performance-based, or a
combination of these maintenance methods), and shall include all batteries associated with the
station dc supply Component Types in a time-based program as described in Table 1-4 and
Table 3. (Part 1.1)
For Component Types that use monitoring to extend the maintenance intervals, the responsible
entity(s) shall have evidence for each Protection System and Automatic Reclosing Component
Type (such as manufacturer’s specifications or engineering drawings) of the appropriate

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Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance
monitored Component attributes as specified in Tables 1-1 through 1-5, Table 2, Table 3, and
Table 4-1 through 4-2. (Part 1.2)

M2. Each Transmission Owner, Generator Owner, and Distribution Provider that uses performancebased maintenance intervals shall have evidence that its current performance-based
maintenance program(s) is in accordance with Requirement R2, which may include but is not
limited to Component lists, dated maintenance records, and dated analysis records and results.

M3. Each Transmission Owner, Generator Owner, and Distribution Provider that utilizes timebased maintenance program(s) shall have evidence that it has maintained its Protection System
and Automatic Reclosing Components included within its time-based program in accordance
with Requirement R3. The evidence may include but is not limited to dated maintenance
records, dated maintenance summaries, dated check-off lists, dated inspection records, or dated
work orders.

M4. Each Transmission Owner, Generator Owner, and Distribution Provider that utilizes
performance-based maintenance intervals in accordance with Requirement R2 shall have
evidence that it has implemented the Protection System Maintenance Program for the
Protection System and Automatic Reclosing Components included in its performance-based
program in accordance with Requirement R4. The evidence may include but is not limited to
dated maintenance records, dated maintenance summaries, dated check-off lists, dated
inspection records, or dated work orders.

M5. Each Transmission Owner, Generator Owner, and Distribution Provider shall have evidence
that it has undertaken efforts to correct identified Unresolved Maintenance Issues in
accordance with Requirement R5. The evidence may include but is not limited to work orders,
replacement Component orders, invoices, project schedules with completed milestones, return
material authorizations (RMAs) or purchase orders.

D. Compliance
1.
Compliance Monitoring Process
1.1. Compliance Enforcement Authority
As defined in the NERC Rules of Procedure, “Compliance Enforcement Authority”
means NERC or the Regional Entity in their respective roles of monitoring and enforcing
compliance with the NERC Reliability Standards.

1.2. Compliance Monitoring and Enforcement Processes:
Compliance Audit
Self-Certification
Spot Checking
Compliance Investigation
Self-Reporting
Complaint

1.3. Evidence Retention
The following evidence retention periods identify the period of time an entity is required
to retain specific evidence to demonstrate compliance. For instances where the evidence
retention period specified below is shorter than the time since the last audit, the
Compliance Enforcement Authority may ask an entity to provide other evidence to show
that it was compliant for the full time period since the last audit.

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Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance
The Transmission Owner, Generator Owner, and Distribution Provider shall each keep
data or evidence to show compliance as identified below unless directed by its
Compliance Enforcement Authority to retain specific evidence for a longer period of time
as part of an investigation.
For Requirement R1, the Transmission Owner, Generator Owner, and Distribution
Provider shall each keep its current dated Protection System Maintenance Program, as
well as any superseded versions since the preceding compliance audit, including the
documentation that specifies the type of maintenance program applied for each Protection
System Component Type.
For Requirement R2, Requirement R3, Requirement R4, and Requirement R5, the
Transmission Owner, Generator Owner, and Distribution Provider shall each keep
documentation of the two most recent performances of each distinct maintenance activity
for the Protection System or Automatic Reclosing Component, or all performances of
each distinct maintenance activity for the Protection System or Automatic Reclosing
Component since the previous scheduled audit date, whichever is longer.
The Compliance Enforcement Authority shall keep the last audit records and all
requested and submitted subsequent audit records.

1.4. Additional Compliance Information
None.

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Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

2.

Violation Severity Levels

Requirement
Number

Lower VSL

Moderate VSL

High VSL

Severe VSL

R1

The responsible entity’s PSMP failed
to specify whether one Component
Type is being addressed by timebased or performance-based
maintenance, or a combination of
both. (Part 1.1)
OR
The responsible entity’s PSMP failed
to include applicable station batteries
in a time-based program. (Part 1.1)

The responsible entity’s PSMP
failed to specify whether two
Component Types are being
addressed by time-based or
performance-based maintenance, or
a combination of both. (Part 1.1)

The responsible entity’s PSMP
failed to specify whether three
Component Types are being
addressed by time-based or
performance-based maintenance, or
a combination of both. (Part 1.1).
OR
The responsible entity’s PSMP
failed to include the applicable
monitoring attributes applied to each
Component Type consistent with the
maintenance intervals specified in
Tables 1-1 through 1-5, Table 2,
Table 3, and Tables 4-1 through 4-2
where monitoring is used to extend
the maintenance intervals beyond
those specified for unmonitored
Components. (Part 1.2).

The responsible entity failed to
establish a PSMP.
OR
The responsible entity’s PSMP
failed to specify whether four or
more Component Types are being
addressed by time-based or
performance-based maintenance, or
a combination of both. (Part 1.1).

R2

The responsible entity uses
performance-based maintenance
intervals in its PSMP but failed to
reduce Countable Events to no more
than 4% within three years.

NA

The responsible entity uses
performance-based maintenance
intervals in its PSMP but failed to
reduce Countable Events to no more
than 4% within four years.

The responsible entity uses
performance-based maintenance
intervals in its PSMP but:
1) Failed to establish the technical
justification described within
Requirement R2 for the initial
use of the performance-based
PSMP
OR
2) Failed to reduce Countable
Events to no more than 4%
within five years
OR
3) Maintained a Segment with

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Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

Requirement
Number

Lower VSL

Moderate VSL

High VSL

Severe VSL
less than 60 Components
OR
4) Failed to:
• Annually update the list of
Components,
OR
• Annually perform
maintenance on the greater
of 5% of the Segment
population or 3
Components,
OR
• Annually analyze the
program activities and
results for each Segment.

R3

For Components included within a
time-based maintenance program, the
responsible entity failed to maintain
5% or less of the total Components
included within a specific
Component Type, in accordance with
the minimum maintenance activities
and maximum maintenance intervals
prescribed within Tables 1-1 through
1-5, Table 2, Table 3, and Tables 4-1
through 4-2.

For Components included within a
time-based maintenance program,
the responsible entity failed to
maintain more than 5% but 10% or
less of the total Components
included within a specific
Component Type, in accordance
with the minimum maintenance
activities and maximum
maintenance intervals prescribed
within Tables 1-1 through 1-5,
Table 2, Table 3, and Tables 4-1
through 4-2.

For Components included within a
time-based maintenance program,
the responsible entity failed to
maintain more than 10% but 15% or
less of the total Components
included within a specific
Component Type, in accordance
with the minimum maintenance
activities and maximum
maintenance intervals prescribed
within Tables 1-1 through 1-5, Table
2, Table 3, and Tables 4-1 through
4-2.

For Components included within a
time-based maintenance program,
the responsible entity failed to
maintain more than 15% of the total
Components included within a
specific Component Type, in
accordance with the minimum
maintenance activities and
maximum maintenance intervals
prescribed within Tables 1-1
through 1-5, Table 2, Table 3, and
Tables 4-1 through 4-2.

R4

For Components included within a
performance-based maintenance
program, the responsible entity failed
to maintain 5% or less of the annual
scheduled maintenance for a specific
Component Type in accordance with

For Components included within a
performance-based maintenance
program, the responsible entity
failed to maintain more than 5% but
10% or less of the annual scheduled
maintenance for a specific
Component Type in accordance

For Components included within a
performance-based maintenance
program, the responsible entity
failed to maintain more than 10%
but 15% or less of the annual
scheduled maintenance for a specific
Component Type in accordance with

For Components included within a
performance-based maintenance
program, the responsible entity
failed to maintain more than 15%
of the annual scheduled
maintenance for a specific
Component Type in accordance
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Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

Requirement
Number

R5

Lower VSL

Moderate VSL

High VSL

Severe VSL

their performance-based PSMP.

with their performance-based
PSMP.

their performance-based PSMP.

with their performance-based
PSMP.

The responsible entity failed to
undertake efforts to correct 5 or
fewer identified Unresolved
Maintenance Issues.

The responsible entity failed to
undertake efforts to correct greater
than 5, but less than or equal to 10
identified Unresolved Maintenance
Issues.

The responsible entity failed to
undertake efforts to correct greater
than 10, but less than or equal to 15
identified Unresolved Maintenance
Issues.

The responsible entity failed to
undertake efforts to correct greater
than 15 identified Unresolved
Maintenance Issues.

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Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

E. Regional Variances
None

F. Supplemental Reference Document
The following documents present a detailed discussion about determination of maintenance intervals
and other useful information regarding establishment of a maintenance program.
1. PRC-005-2 Protection System Maintenance Supplementary Reference and FAQ — March 2013.
2. Considerations for Maintenance and Testing of Autoreclosing Schemes — November 2012.
Version History
Version

Date

Action

Change Tracking

0

April 1, 2005

Effective Date

New

1

December 1,
2005

1. Changed incorrect use of certain
hyphens (-) to “en dash” (–) and “em
dash (—).”
2. Added “periods” to items where
appropriate.
3. Changed “Timeframe” to “Time Frame”
in item D, 1.2.

01/20/05

1a

February 17,
2011

Added Appendix 1 - Interpretation
regarding applicability of standard to
protection of radially connected
transformers

Project 2009-17
interpretation

1a

February 17,
2011

Adopted by Board of Trustees

1a

September 26,
2011

FERC Order issued approving interpretation
of R1 and R2 (FERC’s Order is effective as
of September 26, 2011)

1.1a

February 1,
2012

Errata change: Clarified inclusion of
generator interconnection Facility in
Generator Owner’s responsibility

Revision under Project
2010-07

1b

February 3,
2012

FERC Order issued approving interpretation
of R1, R1.1, and R1.2 (FERC’s Order dated
March 14, 2012). Updated version from 1a
to 1b.

Project 2009-10
Interpretation

April 23, 2012

Updated standard version to 1.1b to reflect
FERC approval of PRC-005-1b.

Revision under Project
2010-07

1.1b

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Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

1.1b

May 9, 2012

PRC-005-1.1b was adopted by the Board of
Trustees as part of Project 2010-07
(GOTO).

2

November 7,
2012

Adopted by Board of Trustees

October 17,
2013

Errata Change: The Standards Committee
approved an errata change to the
implementation plan for PRC-005-2 to add
the phrase “or as otherwise made effective
pursuant to the laws applicable to such ERO
governmental authorities;” to the second
sentence under the “Retirement of Existing

November 7,
2013

Adopted by the NERC Board of Trustees

2

3

Project 2007-17 Complete revision,
absorbing maintenance
requirements from PRC005-1.1b, PRC-008-0,
PRC-011-0, PRC-017-0

Revised to address the
FERC directive in Order
No.758 to include
Automatic Reclosing in
maintenance programs.

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Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

Table 1-1
Component Type - Protective Relay
Excluding distributed UFLS and distributed UVLS (see Table 3)
Component Attributes

Maximum
Maintenance
Interval2

Maintenance Activities
For all unmonitored relays:
 Verify that settings are as specified
For non-microprocessor relays:

Any unmonitored protective relay not having all the monitoring attributes
of a category below.

6 Calendar
Years

 Test and, if necessary calibrate
For microprocessor relays:
 Verify operation of the relay inputs and outputs that are essential
to proper functioning of the Protection System.
 Verify acceptable measurement of power system input values.

Monitored microprocessor protective relay with the following:

Verify:

 Internal self-diagnosis and alarming (see Table 2).
 Voltage and/or current waveform sampling three or more times per
power cycle, and conversion of samples to numeric values for
measurement calculations by microprocessor electronics.
 Alarming for power supply failure (see Table 2).

 Settings are as specified.
12 Calendar
Years

 Operation of the relay inputs and outputs that are essential to
proper functioning of the Protection System.
 Acceptable measurement of power system input values.

2

For the tables in this standard, a calendar year starts on the first day of a new year (January 1) after a maintenance activity has been completed.
For the tables in this standard, a calendar month starts on the first day of the first month after a maintenance activity has been completed.

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Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

Table 1-1
Component Type - Protective Relay
Excluding distributed UFLS and distributed UVLS (see Table 3)
Component Attributes

Maximum
Maintenance
Interval2

Maintenance Activities

Monitored microprocessor protective relay with preceding row attributes
and the following:
 Ac measurements are continuously verified by comparison to an
independent ac measurement source, with alarming for excessive error
(See Table 2).
 Some or all binary or status inputs and control outputs are monitored
by a process that continuously demonstrates ability to perform as
designed, with alarming for failure (See Table 2).

12 Calendar
Years

Verify only the unmonitored relay inputs and outputs that are
essential to proper functioning of the Protection System.

 Alarming for change of settings (See Table 2).

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Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

Table 1-2
Component Type - Communications Systems
Excluding distributed UFLS and distributed UVLS (see Table 3)
Component Attributes

Maximum
Maintenance
Interval
4 Calendar
Months

Any unmonitored communications system necessary for correct operation of
protective functions, and not having all the monitoring attributes of a category
below.

6 Calendar
Years

Maintenance Activities

Verify that the communications system is functional.

Verify that the communications system meets performance
criteria pertinent to the communications technology applied (e.g.
signal level, reflected power, or data error rate).
Verify operation of communications system inputs and outputs
that are essential to proper functioning of the Protection System.

Any communications system with continuous monitoring or periodic
automated testing for the presence of the channel function, and alarming for
loss of function (See Table 2).

12 Calendar
Years

Verify that the communications system meets performance
criteria pertinent to the communications technology applied (e.g.
signal level, reflected power, or data error rate).
Verify operation of communications system inputs and outputs
that are essential to proper functioning of the Protection System.

Any communications system with all of the following:
 Continuous monitoring or periodic automated testing for the performance
of the channel using criteria pertinent to the communications technology
applied (e.g. signal level, reflected power, or data error rate, and alarming
for excessive performance degradation). (See Table 2)

12 Calendar
Years

Verify only the unmonitored communications system inputs and
outputs that are essential to proper functioning of the Protection
System

 Some or all binary or status inputs and control outputs are monitored by a
process that continuously demonstrates ability to perform as designed,
with alarming for failure (See Table 2).

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Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

Table 1-3
Component Type - Voltage and Current Sensing Devices Providing Inputs to Protective Relays
Excluding distributed UFLS and distributed UVLS (see Table 3)
Component Attributes

Any voltage and current sensing devices not having monitoring
attributes of the category below.

Voltage and Current Sensing devices connected to microprocessor
relays with AC measurements are continuously verified by comparison
of sensing input value, as measured by the microprocessor relay, to an
independent ac measurement source, with alarming for unacceptable
error or failure (see Table 2).

Maximum
Maintenance
Interval

Maintenance Activities

12 Calendar Years

Verify that current and voltage signal values are provided to the
protective relays.

No periodic
maintenance
specified

None.

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Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

Table 1-4(a)
Component Type – Protection System Station dc Supply Using Vented Lead-Acid (VLA) Batteries
Excluding distributed UFLS and distributed UVLS (see Table 3)
Protection System Station dc supply used only for non-BES interrupting devices for SPS, non-distributed UFLS systems, or nondistributed UVLS systems is excluded (see Table 1-4(e)).
Component Attributes

Maximum
Maintenance
Interval

Maintenance Activities

Verify:
 Station dc supply voltage
4 Calendar Months

Inspect:
 Electrolyte level
 For unintentional grounds
Verify:

Protection System Station dc supply using Vented Lead-Acid
(VLA) batteries not having monitoring attributes of Table 14(f).

 Float voltage of battery charger
 Battery continuity
 Battery terminal connection resistance
18 Calendar
Months

 Battery intercell or unit-to-unit connection resistance
Inspect:
 Cell condition of all individual battery cells where cells are visible –
or measure battery cell/unit internal ohmic values where the cells are
not visible
 Physical condition of battery rack

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Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

Table 1-4(a)
Component Type – Protection System Station dc Supply Using Vented Lead-Acid (VLA) Batteries
Excluding distributed UFLS and distributed UVLS (see Table 3)
Protection System Station dc supply used only for non-BES interrupting devices for SPS, non-distributed UFLS systems, or nondistributed UVLS systems is excluded (see Table 1-4(e)).
Component Attributes

Maximum
Maintenance
Interval

18 Calendar
Months
-or6 Calendar Years

Maintenance Activities

Verify that the station battery can perform as manufactured by
evaluating cell/unit measurements indicative of battery performance
(e.g. internal ohmic values or float current) against the station battery
baseline.
-orVerify that the station battery can perform as manufactured by
conducting a performance or modified performance capacity test of the
entire battery bank.

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Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

Table 1-4(b)
Component Type – Protection System Station dc Supply Using Valve-Regulated Lead-Acid (VRLA) Batteries
Excluding distributed UFLS and distributed UVLS (see Table 3)
Protection System Station dc supply used only for non-BES interrupting devices for SPS, non-distributed UFLS systems, or nondistributed UVLS systems is excluded (see Table 1-4(e)).
Component Attributes

Maximum
Maintenance
Interval

Maintenance Activities

Verify:
4 Calendar Months

 Station dc supply voltage
Inspect:
 For unintentional grounds
Inspect:

6 Calendar Months
Protection System Station dc supply with Valve Regulated
Lead-Acid (VRLA) batteries not having monitoring attributes
of Table 1-4(f).

 Condition of all individual units by measuring battery cell/unit
internal ohmic values.
Verify:
 Float voltage of battery charger
 Battery continuity

18 Calendar
Months

 Battery terminal connection resistance
 Battery intercell or unit-to-unit connection resistance
Inspect:
 Physical condition of battery rack

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Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

Table 1-4(b)
Component Type – Protection System Station dc Supply Using Valve-Regulated Lead-Acid (VRLA) Batteries
Excluding distributed UFLS and distributed UVLS (see Table 3)
Protection System Station dc supply used only for non-BES interrupting devices for SPS, non-distributed UFLS systems, or nondistributed UVLS systems is excluded (see Table 1-4(e)).
Component Attributes

Maximum
Maintenance
Interval

6 Calendar Months
-or3 Calendar Years

Maintenance Activities

Verify that the station battery can perform as manufactured by
evaluating cell/unit measurements indicative of battery performance
(e.g. internal ohmic values or float current) against the station battery
baseline.
-orVerify that the station battery can perform as manufactured by
conducting a performance or modified performance capacity test of the
entire battery bank.

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Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

Table 1-4(c)
Component Type – Protection System Station dc Supply Using Nickel-Cadmium (NiCad) Batteries
Excluding distributed UFLS and distributed UVLS (see Table 3)
Protection System Station dc supply used only for non-BES interrupting devices for SPS, non-distributed UFLS system, or nondistributed UVLS systems is excluded (see Table 1-4(e)).
Component Attributes

Maximum
Maintenance
Interval

Maintenance Activities

Verify:
 Station dc supply voltage
4 Calendar Months

Inspect:
 Electrolyte level
 For unintentional grounds
Verify:

Protection System Station dc supply Nickel-Cadmium
(NiCad) batteries not having monitoring attributes of Table 14(f).

 Float voltage of battery charger
 Battery continuity
18 Calendar
Months

 Battery terminal connection resistance
 Battery intercell or unit-to-unit connection resistance
Inspect:
 Cell condition of all individual battery cells.
 Physical condition of battery rack

6 Calendar Years

Verify that the station battery can perform as manufactured by
conducting a performance or modified performance capacity test of the
entire battery bank.

19

Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

Table 1-4(d)
Component Type – Protection System Station dc Supply Using Non Battery Based Energy Storage
Excluding distributed UFLS and distributed UVLS (see Table 3)
Protection System Station dc supply used only for non-BES interrupting devices for SPS, non-distributed UFLS system, or nondistributed UVLS systems is excluded (see Table 1-4(e)).

Component Attributes

Maximum
Maintenance
Interval

Maintenance Activities

Verify:
4 Calendar Months

 Station dc supply voltage
Inspect:
 For unintentional grounds

Any Protection System station dc supply not using a battery
and not having monitoring attributes of Table 1-4(f).

18 Calendar Months

Inspect:
Condition of non-battery based dc supply

6 Calendar Years

Verify that the dc supply can perform as manufactured when ac power is
not present.

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Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

Table 1-4(e)
Component Type – Protection System Station dc Supply for non-BES Interrupting Devices for SPS, non-distributed UFLS, and nondistributed UVLS systems

Component Attributes

Any Protection System dc supply used for tripping only nonBES interrupting devices as part of a SPS, non-distributed
UFLS, or non-distributed UVLS system and not having
monitoring attributes of Table 1-4(f).

Maximum
Maintenance
Interval
When control
circuits are verified
(See Table 1-5)

Maintenance Activities

Verify Station dc supply voltage.

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Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

Table 1-4(f)
Exclusions for Protection System Station dc Supply Monitoring Devices and Systems
Component Attributes

Maximum Maintenance
Interval

Maintenance Activities

Any station dc supply with high and low voltage monitoring
and alarming of the battery charger voltage to detect charger
overvoltage and charger failure (See Table 2).

No periodic verification of station dc supply voltage is
required.

Any battery based station dc supply with electrolyte level
monitoring and alarming in every cell (See Table 2).

No periodic inspection of the electrolyte level for each cell is
required.

Any station dc supply with unintentional dc ground monitoring
and alarming (See Table 2).

No periodic inspection of unintentional dc grounds is
required.

Any station dc supply with charger float voltage monitoring
and alarming to ensure correct float voltage is being applied on
the station dc supply (See Table 2).

No periodic verification of float voltage of battery charger is
required.

Any battery based station dc supply with monitoring and
alarming of battery string continuity (See Table 2).

No periodic maintenance
specified

No periodic verification of the battery continuity is required.

Any battery based station dc supply with monitoring and
alarming of the intercell and/or terminal connection detail
resistance of the entire battery (See Table 2).

No periodic verification of the intercell and terminal
connection resistance is required.

Any Valve Regulated Lead-Acid (VRLA) or Vented LeadAcid (VLA) station battery with internal ohmic value or float
current monitoring and alarming, and evaluating present values
relative to baseline internal ohmic values for every cell/unit
(See Table 2).

No periodic evaluation relative to baseline of battery cell/unit
measurements indicative of battery performance is required to
verify the station battery can perform as manufactured.

Any Valve Regulated Lead-Acid (VRLA) or Vented LeadAcid (VLA) station battery with monitoring and alarming of
each cell/unit internal ohmic value (See Table 2).

No periodic inspection of the condition of all individual units
by measuring battery cell/unit internal ohmic values of a
station VRLA or Vented Lead-Acid (VLA) battery is
required.

22

Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

Table 1-5
Component Type - Control Circuitry Associated With Protective Functions
Excluding distributed UFLS and distributed UVLS (see Table 3)
Note: Table requirements apply to all Control Circuitry Components of Protection Systems, and SPSs except as noted.
Component Attributes

Maximum
Maintenance
Interval

Maintenance Activities

Trip coils or actuators of circuit breakers, interrupting devices, or mitigating
devices (regardless of any monitoring of the control circuitry).

6 Calendar
Years

Verify that each trip coil is able to operate the circuit
breaker, interrupting device, or mitigating device.

Electromechanical lockout devices which are directly in a trip path from the
protective relay to the interrupting device trip coil (regardless of any
monitoring of the control circuitry).

6 Calendar
Years

Verify electrical operation of electromechanical lockout
devices.

(See Table 4-2(b) for SPS which include Automatic Reclosing.)

12 Calendar
Years

Verify all paths of the control circuits essential for proper
operation of the SPS.

Unmonitored control circuitry associated with protective functions inclusive of
all auxiliary relays.

12 Calendar
Years

Verify all paths of the trip circuits inclusive of all auxiliary
relays through the trip coil(s) of the circuit breakers or other
interrupting devices.

Control circuitry associated with protective functions and/or SPSs whose
integrity is monitored and alarmed (See Table 2).

No periodic
maintenance
specified

None.

Unmonitored control circuitry associated with SPS.

23

Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

Table 2 – Alarming Paths and Monitoring
In Tables 1-1 through 1-5, Table 3, and Tables 4-1 through 4-2, alarm attributes used to justify extended maximum maintenance
intervals and/or reduced maintenance activities are subject to the following maintenance requirements
Component Attributes
Any alarm path through which alarms in Tables 1-1 through 1-5, Table 3, and
Tables 4-1 through 4-2 are conveyed from the alarm origin to the location where
corrective action can be initiated, and not having all the attributes of the “Alarm
Path with monitoring” category below.

Maximum
Maintenance
Interval

Maintenance Activities

12 Calendar Years

Verify that the alarm path conveys alarm signals to
a location where corrective action can be initiated.

Alarms are reported within 24 hours of detection to a location where corrective
action can be initiated.
Alarm Path with monitoring:
The location where corrective action is taken receives an alarm within 24 hours
for failure of any portion of the alarming path from the alarm origin to the
location where corrective action can be initiated.

No periodic
maintenance
specified

None.

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Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

Table 3
Maintenance Activities and Intervals for distributed UFLS and distributed UVLS Systems
Component Attributes

Maximum
Maintenance
Interval

Maintenance Activities

Verify that settings are as specified.
For non-microprocessor relays:
 Test and, if necessary calibrate.
Any unmonitored protective relay not having all the monitoring attributes of a
category below.

6 Calendar
Years

For microprocessor relays:
 Verify operation of the relay inputs and outputs that are
essential to proper functioning of the Protection System.
 Verify acceptable measurement of power system input
values.

Monitored microprocessor protective relay with the following:

Verify:

 Internal self diagnosis and alarming (See Table 2).
 Voltage and/or current waveform sampling three or more times per power
cycle, and conversion of samples to numeric values for measurement
calculations by microprocessor electronics.

 Settings are as specified.
12 Calendar
Years

 Operation of the relay inputs and outputs that are essential to
proper functioning of the Protection System.
 Acceptable measurement of power system input values

Alarming for power supply failure (See Table 2).
Monitored microprocessor protective relay with preceding row attributes and
the following:
 Ac measurements are continuously verified by comparison to an
independent ac measurement source, with alarming for excessive error
(See Table 2).
 Some or all binary or status inputs and control outputs are monitored by a
process that continuously demonstrates ability to perform as designed,
with alarming for failure (See Table 2).

12 Calendar
Years

Verify only the unmonitored relay inputs and outputs that are
essential to proper functioning of the Protection System.

Alarming for change of settings (See Table 2).

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Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

Table 3
Maintenance Activities and Intervals for distributed UFLS and distributed UVLS Systems
Component Attributes

Maximum
Maintenance
Interval

Maintenance Activities

Voltage and/or current sensing devices associated with UFLS or UVLS
systems.

12 Calendar
Years

Verify that current and/or voltage signal values are provided to
the protective relays.

Protection System dc supply for tripping non-BES interrupting devices used
only for a UFLS or UVLS system.

12 Calendar
Years

Verify Protection System dc supply voltage.

Control circuitry between the UFLS or UVLS relays and electromechanical
lockout and/or tripping auxiliary devices (excludes non-BES interrupting
device trip coils).

12 Calendar
Years

Verify the path from the relay to the lockout and/or tripping
auxiliary relay (including essential supervisory logic).

Electromechanical lockout and/or tripping auxiliary devices associated only
with UFLS or UVLS systems (excludes non-BES interrupting device trip
coils).

12 Calendar
Years

Verify electrical operation of electromechanical lockout and/or
tripping auxiliary devices.

Control circuitry between the electromechanical lockout and/or tripping
auxiliary devices and the non-BES interrupting devices in UFLS or UVLS
systems, or between UFLS or UVLS relays (with no interposing
electromechanical lockout or auxiliary device) and the non-BES interrupting
devices (excludes non-BES interrupting device trip coils).

No periodic
maintenance
specified

None.

Trip coils of non-BES interrupting devices in UFLS or UVLS systems.

No periodic
maintenance
specified

None.

26

Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

Table 4-1
Maintenance Activities and Intervals for Automatic Reclosing Components
Component Type – Reclosing Relay
Component Attributes

Maximum
Maintenance
Interval

Maintenance Activities

Verify that settings are as specified.
For non-microprocessor relays:
Any unmonitored reclosing relay not having all the monitoring attributes of a
category below.

6 Calendar
Years

 Test and, if necessary calibrate
For microprocessor relays:
 Verify operation of the relay inputs and outputs that are
essential to proper functioning of the Automatic Reclosing.
Verify:

Monitored microprocessor reclosing relay with the following:
 Internal self diagnosis and alarming (See Table 2).
 Alarming for power supply failure (See Table 2).

12 Calendar
Years

 Settings are as specified.
 Operation of the relay inputs and outputs that are essential to
proper functioning of the Automatic Reclosing.

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Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

Table 4-2(a)
Maintenance Activities and Intervals for Automatic Reclosing Components
Component Type – Control Circuitry Associated with Reclosing Relays that are NOT an Integral Part of an SPS
Maximum
Maintenance
Interval

Maintenance Activities

Unmonitored Control circuitry associated with Automatic Reclosing that is
not an integral part of an SPS.

12 Calendar
Years

Verify that Automatic Reclosing, upon initiation, does not
issue a premature closing command to the close circuitry.

Control circuitry associated with Automatic Reclosing that is not part of an
SPS and is monitored and alarmed for conditions that would result in a
premature closing command. (See Table 2)

No periodic
maintenance
specified

None.

Component Attributes

28

Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance

Table 4-2(b)
Maintenance Activities and Intervals for Automatic Reclosing Components
Component Type – Control Circuitry Associated with Reclosing Relays that ARE an Integral Part of an SPS
Component Attributes

Maximum
Maintenance
Interval

Maintenance Activities

Close coils or actuators of circuit breakers or similar devices that are used in
conjunction with Automatic Reclosing as part of an SPS (regardless of any
monitoring of the control circuitry).

6 Calendar
Years

Verify that each close coil or actuator is able to operate the
circuit breaker or mitigating device.

Unmonitored close control circuitry associated with Automatic Reclosing
used as an integral part of an SPS.

12 Calendar
Years

Verify all paths of the control circuits associated with Automatic
Reclosing that are essential for proper operation of the SPS.

Control circuitry associated with Automatic Reclosing that is an integral part
of an SPS whose integrity is monitored and alarmed. (See Table 2)

No periodic
maintenance
specified

None.

29

Standard PRC-005-3 — Protection System and Automatic Reclosing Maintenance
PRC-005 — Attachment A
Criteria for a Performance-Based Protection System Maintenance Program

Purpose: To establish a technical basis for initial and continued use of a performance-based
Protection System Maintenance Program (PSMP).
To establish the technical justification for the initial use of a performance-based PSMP:
1. Develop a list with a description of Components included in each designated Segment,
with a minimum Segment population of 60 Components.
2. Maintain the Components in each Segment according to the time-based maximum
allowable intervals established in Tables 1-1 through 1-5, Table 3, and Tables 4-1
through 4-2 until results of maintenance activities for the Segment are available for a
minimum of 30 individual Components of the Segment.
3. Document the maintenance program activities and results for each Segment, including
maintenance dates and Countable Events for each included Component.
4. Analyze the maintenance program activities and results for each Segment to determine
the overall performance of the Segment and develop maintenance intervals.
5. Determine the maximum allowable maintenance interval for each Segment such that the
Segment experiences Countable Events on no more than 4% of the Components within
the Segment, for the greater of either the last 30 Components maintained or all
Components maintained in the previous year.
To maintain the technical justification for the ongoing use of a performance-based PSMP:
1. At least annually, update the list of Components and Segments and/or description if any
changes occur within the Segment.
2. Perform maintenance on the greater of 5% of the Components (addressed in the
performance based PSMP) in each Segment or 3 individual Components within the
Segment in each year.
3. For the prior year, analyze the maintenance program activities and results for each
Segment to determine the overall performance of the Segment.
4. Using the prior year’s data, determine the maximum allowable maintenance interval for
each Segment such that the Segment experiences Countable Events on no more than 4%
of the Components within the Segment, for the greater of either the last 30 Components
maintained or all Components maintained in the previous year.
5. If the Components in a Segment maintained through a performance-based PSMP
experience 4% or more Countable Events, develop, document, and implement an action
plan to reduce the Countable Events to less than 4% of the Segment population within 3
years.

30