NOTICE DATE: July 13, 2010

NOTICE TYPE: M-A071310-01 Operations

SHORT DESCRIPTION: Updating West to North Stability Transfer Limits

INTENDED AUDIENCE: ERCOT Market Participants

DAY AFFECTED: July 19, 2010

LONG DESCRIPTION: As a result of its on-going Dynamic Stability analysis, ERCOT is updating the West to North Stability Limits matrix and will be using the updated matrix to determine West to North Stability limits effective July 19, 2010. The updated matrix will be posted at least one day prior to the scheduled implementation at: http://www.ercot.com/gridinfo/congestion/.

Additionally, a voltage stability limit may also be used when necessary in the West Texas region. The new limits will be monitored by System Operations starting at 09:00 on July 19, 2010.

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 Relations via email at [log in to unmask].

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