The Power Ministry said on Tuesday that Saturday’s blackout was caused by a human error. 

According to sources in the Power Ministry, a circuit breaker at the Guddu Power Plant was shut down in a wrong manner and this brought the entire system down. Sources said that maintenance work was under way on a breaker installed in the switchyard when the system collapsed. 

Sources said that earthing of a circuit breaker was done during maintenance and the staff that worked at the plant at day time did not close the system before leaving. The night shift staff closed the circuit breaker without stopping the earthing process. 

This circuit breaker installed in the switchyard was controlled directly from the control room. Closure of the circuit breaker in a wrong way caused the national power breakout on Saturday night after the Guddu Power Plant collapsed. After the Guddu Power Plant collapsed, the power transmission line originating from the plan also tripped. 

Sources also said that maintenance work on the breaker of the power plant was being done without approval of the authorities concerned. According to the sources, approval from the National Power Control Centre was required to do maintenance work at the Guddu Power Plant.