NOTICE DATE:  January 15, 2013

NOTICE TYPE:  M-A122712-02 Operations

SHORT DESCRIPTION:  Update to CREZ double circuit transmission lines known as Brown – Newton – Killeen 345 kV

INTENDED AUDIENCE:  ERCOT Market Participants

DAYS AFFECTED:  January 15, 2013, and ongoing

LONG DESCRIPTION:  On January 11, 2013, Oncor Electric Delivery Company, LLC (Oncor) identified issues which required derating the (CREZ) double circuit transmission lines known as Brown – Newton – Killeen 345 kV. The CREZ transmission lines were designed for a maximum capacity of 3,000 amps per circuit but had previously been derated to 1,000 amps per circuit (see notice M-A122712-01). Oncor has informed ERCOT that due to proximity issues and updated field measurements, induced voltages on non-Transmission Facilities have resulted in the need for further deration of these transmission lines to 500 amps per circuit. Operational studies performed by ERCOT with these lower ratings on the Brown – Newton – Killeen 345 kV circuits, have shown that the removal of these lines from service until mitigation efforts to increase the ratings can be taken is necessary to ensure reliability in the area. Until such mitigation measures are completed, the lines will be removed from service.

It is anticipated that interim mitigation efforts will be completed by the end of February and the Brown – Newton – Killeen 345 kV transmission lines will be returned to service with the restrictions indicated in notice M-A122712-01:

1.    The double circuit Brown – Newton – Killeen 345 kV transmission lines will be operated with both circuits in parallel (as a single circuit line); and

2.    The Brown – Newton – Killeen 345 kV transmission lines will be rated to a maximum capacity of 2,000 amps or 1,000 amps per circuit.

ADDITIONAL INFORMATION:  These circuits may be energized in the event of a transmission emergency, but ERCOT does not plan on requesting ONCOR to energize them until the ratings are increased. The status of these lines are posted in the ERCOT MIS Outage reports and provides the lines expected return to service dates.

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 email at [log in to unmask]<mailto:[log in to unmask]>.

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