Eskom says stage 2 load shedding will resume at 9am and continue over the weekend until 6am on Monday.
This comes after the power utility implemented power cuts from 9pm on Thursday until 6am on Friday due to a constrained power system and the depletion of emergency diesel and water reserves.
Emergency resources were "used extensively to supplement capacity over the past few days".
In a power alert on Friday morning, Eskom said that three major generating units would also be offline for planned maintenance on Friday.
Stage 2 allows for up to 2 000MW to be shed from the national grid, just under five percent of Eskom's total nominal capacity.
Unplanned outages were at 12 722 MW at 5:30am on Friday, above Eskom's goal of 9 500MW.