When reducing energy is not enough
July 20, 2004

A 230-kilovolt (kV) transformer at the Deer Valley substation caught fire this morning, causing removal of the entire facility from service. While substation repairs are in progress, the partial loss of the Deer Valley transformer may make it difficult to meet peak load requirements later this afternoon. As such, curtailment in that particular area is possible today, particularly during the peak energy period of 3 to 6 p.m.

Rolling outages possible
If, despite energy reductions, the demand for power exceeds the Valley's transmission capacity, we may implement involuntary curtailment (short rolling outages) to reduce the electric load to necessary and safe levels.

During curtailment, certain circuits within our service territory will be selected for interruption. These circuits will be opened for a brief period of time (typically 30-60 minutes), then restored into service as another group of circuits is interrupted. Facilities determined to be critical to the welfare of the Valley, such as hospitals and emergency 911 centers, normally are not subject to the power interruptions.

Staying safe
During a power outage, stay calm and stay put. Make sure all appliances and machinery are off. Keep one light on to indicate when the power is restored.