Project 2010-13.1 Phase 1 of Relay Loadability: Transmission
​​​Related Files

Status:
The Relay Loadability Standard Drafting Team is considering the comments received from the posting of the "Determination and Application of Practical Relaying Loadability Ratings" reference document.

Purpose/Industry Need:
This proposed standard will address the cascading transmission outages that occurred in the August 2003 blackout when backup distance and phase relays operated on high loading and low voltage without electrical faults on the protected lines.  This is the so-called 'zone 3 relay' issue, which has been expanded to address other protection devices subject to unintended operation during extreme system conditions.  The standard will establish minimum loadability criteria for these relays to minimize the chance of unnecessary line trips during a major system disturbance.  In December 2005, the Planning Committee approved a white paper providing the engineering basis for the proposed standard, culminating a major project to analyze the performance of existing protection systems and to research preferred set points.

Draft Action Dates Results Consideration of Comments
Relay Loadability Reference Document Clean | Redline        
Relay Loadability Reference Document Reference Document Supporting Materials:
Comment Form (Word)
Comment Period Info>>
3/20/2008 - 5/3/2008
(closed)
Comments Received>>   Consideration of Comments>>
Draft 6
Relay Loadability Standard PRC-023-1
Clean | Redline to initial ballot

Supporting Materials:
Implementation Plan
Reference Document
Posted for 
Board of Trustees Approval
     
 Draft 5
Relay Loadability Standard PRC-023-1
Clean | Redline to initial ballot Supporting Materials:
Implementation Plan Reference Document
Recirculation Ballot

Info>>
1/31/2008 - 2/9/2008 (closed)  Summary>> Full Record>>
 Draft 4
Relay Loadability Standard Clean | Redline to last posting Supporting Materials:
Implementation Plan
Clean | Redline to last posting
Reference Document
Initial Ballot

Info>>
11/19/2007 - 12/4/2007
(closed)
  Summary>>

Full Record>>
Consideration of Comments>>
Pre-ballot Review Info>> 10/18/2007 - 11/19/2007
(closed)
   
 Draft 3
Relay Loadability Standard

Clean | Redline to last posting Supporting Materials:
Implementation Plan
Clean | Redline
Comment Period

Info>>

Submit Comments>>
3/19/2007 - 4/17/2007 (closed) Comments Received>> Consideration of Comments>> Revised
Draft 2
Relay Loadability Standard Clean | Redline to first posting Supporting Materials:
Implementation Plan
Clean | Redline
Relay Loadability Reference
Comment Period

Info>>

Submit Comments>>
   12/9/2007 - 2/7/2007 (closed) Comments Received>> Consideration of Comments>>
Draft 1 Relay Loadability Standard Draft Standard Version 1 Supporting Materials:
Implementation Plan
Reference Document
Comment Period

Info>>

Submit Comments>>
  8/16/2006 - 9/29/2006 (closed) Comments Received>> Consideration of Comments>>
Draft 2 Draft SAR Version 2 - clean Draft SAR Version 2 - redline       
    Standard Drafting Team Nomination Period
Info>>

Submit Nomination>>
  Due 5/3/2006 (closed)     
Draft SAR Version 1 Supporting Materials:
Working Paper on
Proposed Transmission
Relay Loadability
Comment Period
Info>>

SAR Drafting Team Nomination Period
Submit Nomination>>
1/16/2006 - 2/15/2006 (closed) Nominations
Due 2/3/2006
Comments Received>> Consideration of Comments>>
To download a file click on the file using your right mouse button, then save it to your computer in a directory of your choice.
All comments should be forwarded to sarcomm@nerc.net.  
Questions?  Contact Monica Benson - monica.benson@nerc.net or 404-446.2560.