High stages of load shedding will continue to the weekend, Eskom says.
Eskom unions demand a 15% wage increase and other benefits as wage negotiations start this week.
President Cyril Ramaphosa is calling for an urgent meeting to discuss Eskom.
Koeberg unit 2 has tripped, sending South Africa back to indefinite stage 6 load shedding.
And has an important request for South Africans.
Stage 6 load shedding will continue this weekend with a couple of breaks during the day.
Eskom has appointed a new Group Executive for Generation, effective immediately.
Electricity minister Kgosientsho Ramokgopa says Eskom needs more funding to battle load shedding.
The energy minister is warning of dire consequences of the colder months.
Eskom has announced stage 5 load shedding until further notice.