An Essential Energy spokesperson said approximately 9000 customers were affected, from Wallaga Lake and Wandella in the north, to Tathra and Candelo in the south, and including the townships of Bega, Brogo and Bermagui.

Despite its widespread nature, the blackout only lasted from 10.46am until 10.48am.

Essential Energy had crews at the substation at the time who were alerted to the outage immediately and were able to restore power within minutes.

Investigations into the cause of the fault are continuing.