Properties in the south of the town had no electricity for up to two-and-a-half hours due to the problem with the 20,000 volt cable.
Willowburn Sports and Leisure Centre, the Hogs Head Inn, McDonalds, the two filling stations and homes in South Road and Royal Oak Gardens were among those affected.
The fault was reported at 2.55pm and Northern Powergrid engineers rerouted the supply so power could be restored.
A spokeswoman said engineers were unable to investigate the problem fully and would be continuing the fault-finding tomorrow. The investigation is not expected to affect the power supply.