A power outage hit areas south and south-west of Johannesburg on Tuesday afternoon, City Power said.
Spokesman Louis Pieterse said the outage was caused by a problem at a sub station.
“We had a fairly large power outage around 2.45pm on Tuesday afternoon that affected areas like Mondeo, Industria, Mayfair, Eldorado and Lenasia,” he said.
“The technical problem affected a transmission network. We have restored 70% to 80% of the power,” he said by 5.30pm.
Substations were being switched on, one at a time.
Pieterse said electricity supply to all areas should be restored by early evening.