Pretoria - Eskom's Kusile Power Station in Limpopo remained closed following protest action, said the parastatal.
This after 500 workers, who are employed by contractors, downed tools on Tuesday which resulted in damage to vehicles.
"The site has been closed as a precautionary measure, to ensure the safety of all staff," Eskom's spokesperson Hilary Joffe said.
"The build programme is on track, with the first unit of the new power station scheduled to come on line at the end of 2012," she said.
While no injuries were reported on Tuesday the situation at the site is being monitored.
Protest action began last Friday at the site where over 9 000 people are employed. In Friday's incident, protesters set fire to site offices, two mobile cranes and vehicles at the site.
The matter involves a dispute between Kusile Civil Works Joint Venture - which is made up of companies Group Five, WBHO and Stefanutti Stocks - and their workers.