Sections of Oamaru were left without electricity on Thursday afternoon after a power cut caused minor disruption to residents and businesses in the north of the town.
Network Waitaki chief executive Graham Clark said the outage affected only the north end of Oamaru, just north of Orwell St.
Power was restored to customers within 30 minutes.
The cause of the outage, which occurred at 2.55pm, was unknown and was still being investigated, he said.
Although the loss of power caused some disruption at the Whitestone Cheese factory in Torridge St, general manager Simon Berry said the outage did not have a financial impact.
"We lost power for probably 15 minutes or so, lost all our internal lighting and things, but our chillers can cope OK with short power cuts like that. But it was disruptive."
Mr Berry said the disruption had resulted in time delays, but added that there had been no impact on food quality standards.
Waitaki Boys High School rector Paul Jackson said although power was out at the school, there had been little impact on lessons.
"No-one was sent home. There was the odd computer class affected, obviously, but teachers had back-up plans for that eventuality."
