NOTICE DATE: October 30, 2019

NOTICE TYPE: W-B061319-04 Operations

SHORT DESCRIPTION: Update - Proposal to Add Culberson Loop Remedial Action Scheme

INTENDED AUDIENCE: ERCOT Market Participants

DAYS AFFECTED: December 15, 2019

LONG DESCRIPTION: ERCOT has reviewed the proposal from Oncor Electric Delivery Company LLC (Oncor) to add a Remedial Action Scheme (RAS) at Culberson Loop. The Culberson Loop RAS consists of redundant relays placed at every transmission switching station, wired to monitor the status of each transmission line terminal on the Culberson Loop. Under specific system configurations, voltage instability can occur. Oncor’s proposed RAS will automatically perform remedial tripping in response to the specific contingencies of concern.

ERCOT had tentatively approved the Culberson Loop RAS until final verifications could be made using the Network Operations Model.  These verifications are now complete.

The Culberson Loop RAS is fully approved and scheduled to be in-service in December 15, 2019.

ADDITIONAL INFORMATION: Information regarding all RASs can be found in the “Remedial Action Schemes and Constraint Management Plans” portlet located on the Market Information System (MIS) Long-Term Planning page.

Please review the ERCOT website for previous Market Notices related to this subject.

CONTACT: If you have any questions, please contact your ERCOT Account Manager. You may also call the general ERCOT Client Services phone number at (512) 248-3900 or contact ERCOT Client Services via email at ClientServices@ercot.com.

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