KUCHING, July 12 — Investigation carried out by the state-owned power provider Sarawak Energy Berhad (SEB) revealed that the major power outage on Saturday night was caused by lightning strikes on the 275kV Murum junction transmission lines from Murum dam to the Murum junction substation.
The investigations were based on data collected from lightning tracking and recording devices.
SEB group chief executive officer Datuk Sharbini Suhaili said the automatic load shedding mechanism kicked in immediately after the lightning strikes to protect and prevent the grid system from total collapse.
“This effective defence mechanism of automatic load-shedding to protect Sarawak’s total power system enabled SEB to begin progressive supply restoration within 20 minutes after the lightning strikes on the lines,” he said in a statement.
He said investigation further showed that the tripping could have been prevented if the additional double-circuit transmission line project from Murum HEP to Samalaju-B, had been completed on schedule in 2018.
He said this was the first time double-circuit tripping was experienced on the Murum line since it was first commissioned in 2014.
“We sincerely regret and understand the inconvenience this must have caused our customers.
“We are also thankful to our technical front liners for their dedicated efforts to restore power supply to affected customers on Saturday night,” he said, adding that the electricity supply regulator from the state Ministry of Utilities will review and confirm the investigation.
On Saturday night, a double circuit tripping of the 275kV Murum transmission line caused a power outage at about 9.30pm and affected customers in several parts of Sarawak.
SEB, in a statement issued immediately after the power was restored, said major areas affected were Kuching, Sri Aman, Sarikei, Mukah, Sibu, Bintulu and parts of Miri.
Murum is one of the three dams generating power in Sarawak.
The two are Bakun and Batang Ai dams.