MADISON (WKOW) — A failure in a transformer led to the explosion and fire Friday at the Blount Street substation in Madison that cut power to much of downtown Madison.
“We know that our transformer failed, and we are looking at many of its components to identify the root cause,” an American Transmission Company spokesperson said in a statement.
The Wisconsin DNR is supervising the clean up of the site where insulating fluid burned in a fire creating a thick column of smoke which could be seen miles away.
According to ATC, the insulating fluid is a dielectric fluid commonly used for insulating electrical components, and the Wisconsin DNR has confirmed that it does not contain hazardous PCBs.
“Some of the insulating fluid burned in the fire, some was safely pumped from the transformer over the weekend, and our environmental contractor used a skimming method to separate the dielectric fluid from water used to put out the fire that flowed from the substation,” the spokesperson said.
The explosion and subsequent fire at the Blount substation on East Main Street in downtown Madison was reported about 7:40 a.m. Friday, July 19.
This substation contains transmission equipment belonging to ATC and distribution equipment belonging to MGE.
Shortly after the fire at the Blount substation, a second fire occurred in the ATC portion of the East Campus substation near the Kohl Center.
These two substations are connected by the transmission system. While some ATC equipment reportedly incurred damage, MGE equipment was not damaged in this fire.
ATC is leading cleanup of the facilities and the investigation into what caused the Blount and East Campus substation fires and resulting damage. MGE will continue to work with ATC to understand what occurred and to ensure a reliable, resilient electric grid, according to an MGE statement.
Shortly after the fire began Friday, MGE de-energized the Blount Street substation to allow firefighters access. That shut off power to customers in the downtown and Isthmus areas.
MGE crews worked to restore power over the course of the day Friday. By early evening, all power had been restored to customers impacted by the outage.
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