NOTICE DATE:  September 30, 2009

NOTICE TYPE:  M-A081309-03   Operations

SHORT DESCRIPTION:  Official Approval of Modification to the Sandow Switch SPS (Oncor # 43)

INTENDED AUDIENCE:  ERCOT Market Participants

DAY AFFECTED:  August 14, 2009

LONG DESCRIPTION:  ERCOT provisionally approved the modification to the Sandow Switch Special Protection System (SPS) proposed by Oncor Electric Delivery on August 13, 2009. This SPS is intended to protect against post-contingency overloading on the Sandow – Taylor, Sandow – Elgin, and Elgin – Gilleland 138 kV Lines and the Sandow 345/138 kV Autotransformer that may occur under various conditions with the addition of Sandow unit # 5. The modification was implemented on August 14, 2009, raising the arming point of the SPS from 960 Amps to 1428 Amps for the Sandow – Taylor line.

ERCOT has completed its review of the modification and is removing the provisional approval, officially approving the SPS modification 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].

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.

dh