NOTICE DATE:  March 23, 2009 

NOTICE TYPE:  M-A112008-04 Operations

SHORT DESCRIPTION:  Revised Sandow Switch SPS Proposal

INTENDED AUDIENCE:  ERCOT Market Participants

DAY AFFECTED:  March 23, 2009

LONG DESCRIPTION:  The ERCOT ISO provisionally approved the Sandow Switch Special Protection System (SPS) proposed by Oncor Electric Delivery on January 8, 2009.  This SPS involves initiating a safe shut down of Sandow Unit 4 upon detection of the loss of the Sandow Switch 345/138 kV Autotransformer.  It also involves opening the Sandow Switch – Minerva 138 kV Line upon detection of an overload condition on this line.

The ERCOT ISO has completed its review of the Sandow Switch SPS, and is removing the provisional approval, officially approving this SPS at this time.  Further details of the Sandow Switch SPS can be found in the “Special Protection Systems Information” section of the Planning and Operations Information secure website at the link below:

http://planning.ercot.com/login/login

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 e-mail at [log in to unmask].

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kd