In 2011, the North American Electric Reliability Corporation (NERC) released the Protection System Maintenance Standard, PRC-005-2. NERC comes under the Federal Energy Regulatory Commission (FERC). The mission of NERC is to ensure the reliability of the bulk power system in the USA and Canada.
FERC is an independent government agency that is part of the Department of Energy. The purpose of the FERC is to protect the public and energy customers, ensuring that regulated energy companies are acting within the law.
The purpose of PRC-005 (now in the 6th revision, PRC-005-6), is to document and implement programs for the maintenance of all Protection Systems affecting the reliability of the Bulk Electric System (BES) so that these Protection Systems are kept in working order. Compliance is mandatory. NERC defines reliability as Ensuring that the Bulk Power System (BPS) or Bulk Electric System (BES) is able to meet the electricity needs of all end-user customers, even when unexpected equipment failures reduce the amount of available electricity.
Batteries that are used in conjunction with protection systems, fall under the requirements of PRC-005-6. The maintenance requirements for protection system dc supply using Vented Lead-Acid (VLA) and Valve-Regulated Lead-Acid (VRLA) batteries are detailed in Tables 1-4(a), 1-4(b) and 1-4(f) of the document.
There are considerable differences with respect to load testing between the requirement of PRC-005-6, IEEE 450-2010, the IEEE Recommended Practice for Maintenance, Testing, and Replacement of Vented Lead-Acid Batteries for Stationary Applications. And IEEE 1188-2005, the IEEE Recommended Practice for Maintenance, Testing, and Replacement of Valve-Regulated Lead-Acid Batteries for Stationary Applications.