Essential Energy Acting Operations Manager of Riverina Slopes Darren Hockley said the unplanned outage on Thursday night left about 1750 customers without electricity.

"Network protection equipment activated just before midnight after detecting a fault on the high voltage network," he said.

"Crews were dispatched immediately and isolated the damaged equipment, re-routed power around the network and began back-feeding to progressively restore supply to all customers by 1.59am Friday morning."

Repairs needed to the high voltage network are being carried out across the day today, and Mr Hockley said they "apologise for the inconvenience caused by last night's power outage".

Customers are encouraged to report a power outage on 13 20 80 or visit essentialenergy.com.au/outages for updates.