THE recent power disruption at Kuala Lumpur International Airport Terminal 2 (KLIA T2) has been attributed to the presence of circulating current along high-voltage power cables, according to findings from a technical investigation led by Malaysia Airports Holdings Berhad (MAHB).
The Ministry of Transport (MOT) in a statement today said the Cabinet was briefed on MAHB’s report last Wednesday, following the 28 August incident that caused a temporary loss of electrical supply at the terminal.
“MAHB’s technical investigation identified the primary cause of the incident as the presence of circulating current along the cable route between the 33kV substation supplying power to KLIA T2 and the 11kV terminal substation,” the statement read.
“This condition resulted in localised heating at the cable termination point, which led to a flashover incident.”
The ministry added that elevated earth resistance levels also contributed indirectly by preventing the effective dissipation of current into the ground, thereby increasing thermal stress on the protective cable sheath.
In response to the outage, MAHB’s technical team undertook immediate corrective actions. These included repairing all affected cable terminations, installing voltage-limiting sleeves at crossover wiring points to reduce circulating current, and reassessing the earthing configuration along the cable route.
“Other urgent steps included enhancing the preventive maintenance regime by incorporating partial discharge testing and thermographic inspections into the power cable maintenance schedule,” the ministry said.
Looking ahead, MAHB has proposed several long-term upgrades to improve the reliability and safety of the airport’s electrical systems. These include exploring the feasibility of installing an Automatic Transfer Switch (ATS) system to speed up backup power supply activation and expanding generator coverage to safeguard additional critical airport services.
Maintenance intervals for generator load testing at Gateway@klia2 will also be shortened from three months to every two months to ensure higher reliability and early detection of flashover risks.
A comprehensive study is also being carried out to evaluate soil resistance along the cable route, including seasonal variation analysis and the effectiveness of existing earthing systems and crossover wiring. The aim is to better manage the risk of circulating current and improve future grounding performance.
The MOT confirmed that no critical airport operations were disrupted during the incident.
“The Ministry will continue monitoring MAHB’s implementation of follow-up measures to ensure that the safety, efficiency and reliability of the KLIA system remains at its highest standard,” the statement said.
“The government’s main priority is to ensure this incident is addressed immediately with effective preventive measures to avoid any recurrence.”
The 28 August blackout, which occurred at approximately 2:15pm, prompted widespread concern. Transport Minister Anthony Loke previously described the incident as “completely unacceptable” and said it had negatively impacted the country’s image. - September 26, 2025
