SRP Transformer Fire
Fire crews help put out the fire at a Salt River Project facility in east Mesa,
Thursday, June 30, 2011 after a transformer exploded. [Tim Hacker, Tribune]
More than 80,000 people were without power after a transformer exploded at an SRP substation in east Mesa, drawing fire crews from Mesa and Phoenix and overworking at least two other substations throughout the city where power was shifted during the fire.
The outage affected traffic signals at many intersections and also struck businesses and city offices in downtown Mesa. Other parts of the city were experiencing intermittent power outages and rolling blackouts. The areas affected are predominately Dobson Road to the east of the city limits and from U.S. 60 to the northern city border.
"We are not dealing with any increase in heat related incidents due to the power outages," said police spokesman Sgt. Edward Wessing.
Mesa police officers were directing traffic at major intersections and only two collisions had been reported. Dark traffic signals should be treated as stop signs, according to police.
The Salt River Pima-Maricopa Indian Community has also experienced power outages. The town of Fountain Hills said it had been notified by Maricopa County's emergency management department that SRP had announced possible rolling blackouts in response to the Mesa transformer fire.
The outages began minutes after the fire broke out at the Thunderstone substation, according to SRP spokesman Scott Harelson. He said outages could increase due to the demand for power with the summer heat.
“We had some degree of confidence that customers would not be impacted by the fire, but after we shifted all the energy to other substations, it overtaxed them and they started shutting down to protect themselves,” Harelson said. “We are working very hard to restore the power to customers.”
According to SRP, one of the substation’s four transformers exploded about 11:40 a.m. Thursday, causing black smoke that could be seen for miles to rise from the facility northeast of the intersection of Power Road and University Drive and southeast of Red Mountain Park. The smoke originated from the burning of mineral oil that circulates within the transformers to keep them cool, according to Jeff Lane, an SRP spokesman. The three remaining transformers were shut down to protect them and the firefighters as crews faced a challenging situation with a blaze that could not be put out with water.
In less than 30 minutes, customers in eastern and northeast portions of Mesa and Apache Junction flooded SRP’s customer service lines with complaints.
Fire crews doused the fire with foam from a specialized truck. Crews had it extinguished in slightly more than an hour, Harelson said.
The cause of the explosion was unknown and SRP crews were on scene working to restore power to customers. Officials said it was not known when power would be restored and that it could be out for as long as three hours or more.
“The explosion could have been caused by the heat — we don’t know, yet,” Lane said. “Sometimes, transformer explosions are caused by equipment failure. It’s got some burning out to do with the amount of mineral oil that was inside the transformer that cools it off.”
A small mobile home adjacent to the substation was destroyed by the fire caused by the explosion, Lane said.
After a cleanup, SRP will replace the transformer, which costs about $4 million, and conduct an investigation into what caused it to explode. Harelson said the investigation should take about two weeks.