NOTICE DATE: May 25, 2012

NOTICE TYPE: M-B033012-03 Operations

SHORT DESCRIPTION: Implementation of Austrop Autotransformer SPS modification

INTENDED AUDIENCE: ERCOT Market Participants

DAY AFFECTED: June 7, 2012

LONG DESCRIPTION: The modification of the Austrop 138/345kV Autotransformer Special Protection System (“Austrop Auto SPS”) by Austin Energy will be implemented on June 7, 2012. Austin Energy is modifying the Austrop Auto SPS to monitor loading of the Austrop Autotransformers resulting from any contingency.

ADDITIONAL INFORMATION: Information regarding SPSs can be found on the ERCOT Market Information System (MIS) under “Special Protection Systems and Remedial Action Plans” at https://mis.ercot.com/pps/tibco/mis/Pages/Grid+Information/Long+Term+Planning. 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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