NOTICE DATE: July 6, 2015

NOTICE TYPE: M-A070615-01 Operations

SHORT DESCRIPTION: Proposal to Retire Temple Switching Station Special Protection System

INTENDED AUDIENCE: ERCOT Market Participants

DAY AFFECTED: Comments due July 17, 2015

LONG DESCRIPTION: ERCOT has received a proposal to retire the Temple Switching Station Special Protection System (SPS) from Oncor Electric Delivery Company (Oncor). The Temple Switching Station SPS was designed to limit power flow on the 345/138 kV autotransformer at the Temple Switching Station by placing a series reactor in service. This SPS is proposed to be retired in the fall of 2015 when a new 600 MVA 345/138 kV autotransformer is installed to replace the existing autotransformer at Temple Switching Station. Oncor has indicated that the series reactor on the 138 kV side of the Temple Switching Station can be operated manually with supervisory control.

The proposal to disable the Temple Switching Station SPS is being reviewed by ERCOT. Comments on the proposal are due by July 17, 2015 and should be submitted [log in to unmask] using the attached comment form. Any questions or concerns submitted by this date will be addressed by ERCOT or Oncor.

ACTION REQUIRED: Any comments to this proposal are due to ERCOT by July 17, 2015, using the attached form.

ADDITIONAL INFORMATION: Information regarding all SPSs can be found in the “Special Protection Systems and Remedial Action Plans” portlet located on the Long-Term Planning page of ERCOT’s Market Information System (MIS). A digital certificate is required to access the MIS.

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 [log in to unmask].

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