Software and Seminar

NERC PRC-005-2

Did you know that you can attend meetings of the PRC-005-2 drafting team?

Visit for details on the next meeting.

PRC-005-2 is the revised NERC Standard for Protection Systems Maintenance and Testing.

PRC-005-2 has been in the drafting process for 5 years now! The final draft has been successfully balloted and once approved by the stakeholders it goes to the NERC Board of Trustees (BOT). PRC-005-2 is expected to go before the NERC BOT as soon as November 2012 and certainly before the end of 2012.

Update 11-7-12: PRC-005-2 has been approved by the NERC Board of Trustees. It will next move to FERC for study, questions and comments. It would seem unlikely that FERC will not approve it as the next option is to send it back to NERC for another year of arguing within the industry. It would be better to approve PRC-005-2 and seek a PRC-005-3 than to turn aside the ballot approved PRC-005-2. Expect FERC to approve this NERC standard and immediately issue a NOPR for additions and revisions to PRC-005-2. A timetable for the production of PRC-005-3 is already being drawn up. Stay tuned.


So visit and download the version of PRC-005-2 that is expected to receive approval before the end of 2012.

PRC-005-2 states minimum requirements for maintenance for:

Protective Relays

DC Supplies

DC Control Circuits 

Current and Voltage Sensing Devices

Associated Telecommunications Equipment

The standard also states the maximum allowed time intervals between "hands-on" maintenance activity.

The standard PRC-005-2 has balloted but has not yet been adopted as enforceable.


Other PRC5 news:

It is looking more and more like FERC is going to demand additional equipment be added to the next revision of the present standard. In fact the FERC has gone on record with a Notice Of Proposed Regulation (NOPR) stating their present displeasure with the recently balloted (affirmative) interpretation of PRC-005-1.

As of this writing, PRC-005-1 has been interpreted to require maintenance on batteries, but not chargers. Maintenance is required on protective relays, but not restoration relays (auto-reclosing relays). PRC-005-1 has been interpreted to require maintenance on protective relays that receive electrical inputs from voltage and current sensing devices, (not sudden-pressure relays).

The rationale of the Standard Drafting Team that made these interpretations was simple. They were not allowed to re-define the existing PRC-005-1, nor were they to create new definitions. They were charged with the job of interpreting the existing standard, based on the existing NERC definitions.

NERC has a firm definition of what constitutes a Protection System, and PRC-005-1 was written to require maintenance on a Protection System.

The drafting team noted that the Protection System definition presently specifies batteries. It did not specify battery chargers. Hence the interpretation states that battery chargers were not included within the scope of PRC-005-1.

The definition of a Protection system has since had a revision, a successful ballot and approval by both the NERC Board of Trustees and FERC. Battery Chargers are now included within the definition of Protection Systems. This is included as PRC-005-1b and is effective beginning April 1, 2013.

Please note that the Regional Reliability Organization for your area may choose to have more stringent requirements.

Also note that the interpreting team is also the drafting team for PRC-005-2. The revised standard PRC-005-2 will have requirements for maintenance on battery chargers and any power supply system that supplies DC to the Protection System.

There have been published statements that both FERC and NERC were dissatisfied with the interpretations concerning auto-reclosing relays and fault-pressure relays. There is a movement pushing to have these devices included within the requirements of PRC-005-2 or, more likely, a successor to PRC-005-2 

Prudent Protection System owners should be making plans that these other devices will end up in a future version of PRC-005.




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