An 80-kilometre stretch of the Riverina was left without power on Thursday morning after a transmission line running north of Wagga was "tripped".
The outage affected customers from North Wagga to Temora, with residents in Junee and Ganmain also complaining of lost services.
A TransGrid spokesperson said the electricity grid operator was investigating the cause of the trip.
"At 8:49am this morning, line 9J5 from Wagga Wagga North to Temora tripped causing power outages in the area," the spokesperson said.
"The line was restored four minutes later and Essential Energy was notified to progressively resume load. Essential Energy began this process at 9:12am."
Transgrid's Line 9J5 carries 132 kilovolts from a substation in North Wagga to Temora via Junee "supplies many smaller outlying areas" according to Essential Energy's asset distribution report.
Essential Energy's outage tracking website showed one planned outage south of Tumblong and an unplanned outage in Culcairn affecting 40 customers.