Kensington Substation Fire Caused by Battery System Failure

Almost two months after the fire at the Kensington substation, the investigation is complete and the cause has been revealed. At 7:22 p.m. the substation went out of service——due to the failture of a DC battery system, according to Pepco's official report.

The report also stated that age and condition of the battery could have played a role in the failure. Power lines throughout the area experienced faults because of the severe winter weather including ice and strong winds. The faults were cleared by operation of the DC battery, according to the report, but as the storm progressed, the Kensington substation went completley out of service at 7:22 p.m. because of a line fault. The line fault was caused by a combination of the wind, tree contact and snow and ice loadings that resulted in downed wires and trees limbs on the feeders, according to the report.

The fault caused enough force to displace a manhole lid; a second fault in the basement caused structural damage to the building's stairway, access door, windows and roof panels; and a fire within a feeder breaker cubicle that damaged the cubicle with smoke and soot, as detailed in the report.

Pepco gradually restored power to all customers served out of the substation by Saturday, January 29 at 10:26 p.m., and a portion of the substation was back in use the following evening, the report stated.

The substation, which serves Pepco customers in Kensington, Garrett Park, Grosvenor and Wheaton, contains 14 feeders. Twelve of those feeders supply 12,400 customers with electricity, while the other two supply power to a Metro Power Traction Station. According to the report, about 7,100 customers would have lost service even if the substation had remained in use due to storm damage.

For a detailed summary of events, findings and more, read the full 14 page report by clicking on the PDF file in the photo gallery.

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