Eskom said that generation capacity at its power stations would determine whether rolling blackouts would continue beyond Wednesday.
Eskom said that it had lost more generation units and some generators had been delayed in returning to service.
The utility implemented stage 2 power cuts on Sunday.
It has promised that electricity supply will be back to normal from 5am on Wednesday.
Spokesperson Sikonathi Mantshatsha: “The power system remains unpredictable and Eskom would like to inform the public that any further deterioration in generation capacity may require higher stages of load shedding. We, therefore, request the public to continue using electricity sparingly as we strive to return units to service.”