NOTICE DATE: December 18, 2009 NOTICE TYPE: M-A121809-01 Operations SHORT DESCRIPTION: Proposal to disable the Heights SPS INTENDED AUDIENCE: ERCOT Market Participants DAY AFFECTED: January 4, 2010 LONG DESCRIPTION: ERCOT has received a request to permanently disable the Special Protection System (SPS) at the Texas-New Mexico Power Co. (TNMP) Heights substation. This SPS was intended to protect against post-contingency overloading on the Greenbelt - PH Robinson 138 kV line for the loss of the Heights - Freeway Park / PH Robinson 138 kV Double-Circuit. System changes have been completed such that TNMP believes that this SPS can be disabled at this time. ERCOT is initiating a review of this Type-1 SPS. Information regarding SPSs can be viewed on the ERCOT Planning and Operations Information secure website: 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]<mailto:[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<http://lists.ercot.com/>. dh