The Valley’s major electric utilities squeaked by again Wednesday with a reduced power supply after two transformers blew in as many weeks.
"Our electrical equipment operators have been surprised every time about how they’re able to operate on reduced capacity. They’re getting better at it every single day," Salt River Project spokesman Jeff Lane said Wednesday.
Officials at SRP and Arizona Public Service, which together power 1.5 million homes and businesses in the Valley, said conserving is still key, particularly during the peak hours of 3 to 6 p.m.
About 50,000 homes in the north West Valley lost power after Tuesday morning’s transformer fire at APS’ Deer Valley substation. A larger July 4 fire shut down another of the Valley’s four major substations.
APS spokesman Damon Gross said the north West Valley was more vulnerable to power outages but, "We’re in a critical stage for all of our customers. We can’t get that message across enough." About a third of APS’ 700,000 accounts are in the East Valley, he said.
Causes of both fires are under investigation.
The only power outages reported Wednesday were at two Phoenix hospitals served by APS, which switched to their backup generators Wednesday morning after hospital equipment malfunctions, Gross said. Phoenix Children’s Hospital used a backup generator for about an hour beginning about 8:30 a.m. after a palm branch fell on some equipment. John C. Lincoln Hospital North asked to be taken off the grid around the same time to make some repairs.
National Weather Service meteorologist Dennis Sturm said Wednesday’s heat advisory will continue today.
Wednesday’s high at Phoenix Sky Harbor International Airport was 111 degrees with humidity hovering around 13 percent, with similar conditions expected today, he said.