TNB president and chief executive officer Baharin Din said the national grid itself had smart features that facilitated the work of tracing the problem and restoring supply.

“We were able to solve the problem within a reasonable period. Electricity supply in some areas was restored within 20 minutes.

“The restoration of supply could be implemented efficiently as a result of TNB’s continuous investment in modernising the grid, including digitising it so that the supply network is more stable, flexible and consistent,” he said in a statement.

TNB said the blackout which occurred in several areas in the peninsula from 12.39pm was caused by an equipment failure at the Yong Peng North main input substation (PMU) in Johor.

Baharin said the PMU breakdown was an isolated case and did not involve any damage, and the substation was fully operational.

Baharin also apologised to all consumers for the supply disruption and said TNB would conduct a detailed investigation together with the Energy Commission to come up with preventive measures.