NOTICE DATE:  November 20, 2008

NOTICE TYPE:  M-A112008-01 Operations

SHORT DESCRIPTION:  ERCOT ISO Implementation of the Sandow Switch SPS

INTENDED AUDIENCE:  ERCOT Market Participants

DAY AFFECTED:  November 19, 2008

LONG DESCRIPTION:  Oncor Electric Delivery proposed installing a Special Protection System (SPS) at the Sandow Switch substation.  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 granted provisional approval of this SPS, and as of 17:00 on November 19, 2008 this SPS is now in-service.  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].

If you are receiving e-mail from an ERCOT distribution list that you no longer wish to receive, please follow this link in order to unsubscribe from this list: http://lists.ercot.com.