Project 2009-10
Interpretation − PRC-005-1, R1 − CMPWG

Status:
The interpretation was approved by the NERC Board of Trustees on November 5, 2009.

Summary:

The request asks for clarification on the following:

• Does R1 require a maintenance and testing program for the battery chargers for the “station batteries” that are considered part of the Protection System?

• Does R1 require a maintenance and testing program for auxiliary relays and sensing devices? If so, what types of auxiliary relays and sensing devices? (i.e. transformer sudden pressure relays)

• Does R1 require maintenance and testing of transmission line re-closing relays?

• Does R1 require a maintenance and testing program for the DC circuitry that is just the circuitry with relays and devices that control actions on breakers, etc., or does R1 require a program for the entire circuit from the battery charger to the relays to circuit breakers and all associated wiring?

• For R1, what are examples of "associated communications systems" that are part of “Protection Systems” that require a maintenance and testing program?

Purpose/Industry Need:
In accordance with the Reliability Standards Development Procedure, the interpretation must be posted for a 30-day pre-ballot review, and then balloted.  There is no public comment period for an interpretation.  Balloting will be conducted following the same method used for balloting standards.  If the interpretation is approved by its ballot pool, then the interpretation will be appended to the standard and will become effective when adopted by the NERC Board of Trustees and approved by the applicable regulatory authorities.  The interpretation will remain appended to the standard until the standard is revised through the normal standards development process.  When the standard is revised, the clarifications provided by the interpretation will be incorporated into the revised standard.