KUALA LUMPUR, Sept 26 — The Transport Ministry has identified a circulating current within underground cables as the cause of the power outage at KLIA Terminal 2 on Aug 28.
A technical investigation by Malaysia Airports Holdings Berhad (MAHB) found that the current formed between a 33-kilovolt (kV) main substation and several 11kV terminal substations.
This current created localised heating at cable termination points, which ultimately led to a flashover that cut off the electricity supply.
The ministry explained that the problem was exacerbated by high soil resistivity, which prevented the current from discharging effectively into the ground, thereby increasing heat pressure on the cable’s sheath wires and contributing to the system’s failure.
As part of the immediate repairs, MAHB has replaced all affected cable terminations and installed sheath voltage limiters to prevent a recurrence.
The airport operator has also reconfigured its earthing systems and enhanced its maintenance regime to include regular partial discharge tests and thermographic inspections.
Looking ahead, MAHB is exploring several long-term solutions, including the installation of an Automatic Transfer Switch (ATS) to speed up backup power delivery, expanding generator coverage, and shortening generator load test intervals.
Further preventative measures will include in-depth soil resistivity analyses and seasonal assessments to improve grounding systems and manage future risks.
“The government’s main focus is to ensure that this incident is addressed immediately with effective preventive measures so that such occurrences do not happen again,” the ministry said in a statement.
The ministry also noted that MAHB had confirmed no critical airport functions were disrupted during the outage.
It affirmed that it will continue to oversee all system upgrades to ensure the airport’s power supply remains safe and reliable.
