Power outage raises questions

Electric power to all 18,000 UniSource Energy Services customers in Santa Cruz County failed for up to four hours Wednesday.

The utility blamed a broken cross arm on a pole in the Rio Rico area.

But a member of the former Joint City of Nogales-Santa Cruz County Power Commission said, “No excuses are acceptable for any outage in Nogales for over four hours.”

Marshall Magruder, the commissioner, said emergency back-up turbine generators in Nogales should have restored power in the city within 15 minutes.

The commission, which is no longer active, voted in the 1990s to approve plans for a 345,000-volt power line from Tucson to Nogales on the west side of the Santa Cruz Valley. Magruder, however, voted no on that proposal. The Arizona Corporation Commission has also approved, but the line has been delayed.

Work hasn’t started on it.

Joe Salkowski, spokesperson for Tucson Electric Power, a UniSource Energy subsidiary, said the cross bar on a power line from Tucson to Nogales near Rio Rico broke.

He said no reason has been determined for the failure, but said it might have been weather-related. UniSource spokesperson Joe Barrios told the Nogales International newspaper that lightning or wind might have led to the broken cross arm.

“I would consider this more of an anomaly,” he said, adding power poles are inspected routinely.

Magruder said the emergency backup turbines can generate 68 megawatts within 15 minutes.

He said other circuits could have been used to route power to the darkened areas, which is eventually what happened.

“There is NO reason for losing power more than 15 minutes to any single failure of the existing 115kV (115,000 volt) transmission line,” Magruder messaged city, county and state officials.

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