Chuck Bowlin, GLPS superintendent of engineering and operations, said the outage began about 9 a.m.
Power was restored to customers by about 9:20 a.m.
Electrical arcs were seen coming out of a capacitor rack fuse, Bowlin said.
The fire was extinguished by taking the substation offline, Bowlin said. Five other power substations in the area were also powered down until the situation was resolved, he said.
The cause of the equipment failure will be investigated by the Tennessee Valley Authority.
“We’re not sure if an animal or something initiated that,” Bowlin said.