Essential Energy crews responded to the blackout around the Clifton Grove area at 4.20am on Tuesday morning and sectionalised the electricity network to determine the location of the fault and to progressively restore power to customers.

Crews were able to identify a section of the area's underground electricity network where there fault was located and progressively restored power to customers between 6.32am and 7.50am.

Essential Energy Operations Manager Macquarie, Jamie Warren said some customers would have had power restored and then lost intermittently again, but that was part of the process to restore the fault in the line.

"To ensure the safety of the public and their property, after sensing a fault the electricity network automatically switched power off ... this morning," Mr Warren said.

"Crews have rerouted the electricity network around the section of underground electricity network with the fault in it and further investigations will need to occur to determine the exact fault and to enable repairs to be completed," Mr Warren said.

Residents at Clifton Grove have been without electricity since 4.20am on Tuesday morning after a power outage hit the area.

Around 150 Essential Energy customers in the vacinity of Banjo Paterson Way were impacted as of 7.50am, but that number was earlier closer to 700 with the outage extending further west towards the the city.

Areas near Park Street and Dalton Street were earlier affected, while the Canobolas Rural Technology High School was hit too, but as of 8am now had power.

Essential Energy says the source of the power outage is unknown and the company is continuing to investigate the reason for the large blackout.