Power utility Eskom on Wednesday called on consumers to switch off geysers, pool pumps and all non-e.
"He was doing well and says he's feeling OK," close family friend Brian Oxman said.
Oxman, Michael Jackson's one-time attorney, said the 83-year-old patriarch of the pop music family started experiencing weakness on Wednesday while walking in a park near his home and was later admitted to a hospital.
Jackson has a history of strokes, Oxman said.
"He was talking fine," Oxman added. "He sounded excellent to me."
A former U.S. Steel employee from Gary, Indiana, Jackson managed and helped launched the career of his children with the R&B and soul group The Jackson 5 beginning in the 1960s.