Project 2008-02.2 Phase 2 of Undervoltage Load Shedding (UVLS): Misoperations

Related Files | 2008-02 Undervoltage Load Shedding (UVLS) & Underfrequency Load Shedding (UFLS) | 2010-05.1 Protection System (Misoperations)   

Board Adopted: May 7, 2015
Filed with FERC: June 8, 2015
US Enforcement Date
Filings and Orders 
During the development of PRC-004-3 (Project 2010-05.1) and PRC-010-1 (Project 2008-02), both standard drafting teams decided that the UVLS standard drafting team would address the Misoperation of UVLS Protection Systems due to their work involving PRC-022-1 (Under-Voltage Load Shedding Program Performance). The PRC-022-1 Reliability Standard addressed Misoperation of UVLS; however, it is being retired with the creation of PRC-010-1, which was adopted by the NERC Board of Trustees (Board) on November 13, 2014.
This phase of the UVLS project will address Misoperation of UVLS equipment to complete the work anticipated by the two standard drafting teams. The UVLS standard drafting team is currently working to make the necessary standard changes and anticipates submitting proposed changes to NERC Board in May for adoption pending favorable ballot results.
Standard(s) Affected - PRC-004-5 and PRC-010-2
Purpose/Industry Need
A key element for Bulk Electric System (BES) reliability is the correct performance of UVLS Programs that are used in arresting voltage declines and to allow the BES to recover. The identification and correction of any Misoperation of UVLS Protection Systems in a UVLS Program ensures dependable UVLS Program performance.


​Draft ​Actions ​Dates Results ​Consideration of Comments
Final Draft
Implementation Plan
Clean | Redline to Last Posted
Implementation Plan
Clean | Redline to Last Posted
Supporting Materials
Final Ballot
04/17/15 – 04/27/15


Ballot Results

Draft 1

Supporting Materials
Initial Ballot and Non-Binding Poll

Updated Info
​ ​ 03/27/15 - 04/07/15


Ballot Results

Non-binding Poll Results (Updated)

Consideration of Comments
Comment Period
The drafting team did not make substantive changes to PRC-004-5 and PRC-010-2. Therefore, the VRF/VSL Justification documents from the development of PRC-004-3 and PRC-010-1 are posted for reference.
02/20/15 - 04/07/15 Comments Received
Initially, separate ballot pools were incorrectly created for PRC-004-5 and PRC-010-2. 
 The SBS has been updated with one ballot pool to combine PRC-004-5 and PRC-010-2. 
If you have already joined the separate ballot pools, please register in the combined ballot pool.
02/20/15 - 3/23/15
Send RSAW feedback to:
02/20/15 - 04/07/15