“There is a power trip at our primary substation in Rietvlei. Technicians are on site to investigate the cause,” it said in a statement.
The areas of Highveld, Zwartkop and Rooihuiskraal were affected.
The suburb of Eldoraigne was also without power, but this was because of suspected cable theft.
“Electricians are investigating. The city apologises for the inconvenience caused to the affected residents.”