ZAMBOANGA CITY – The Zamboanga City Electric Cooperative (Zamcelco) has implemented a rotational blackout scheme affecting four key feeders following a critical transformer failure during scheduled maintenance. The disruption, which began on Sunday, March 22, 2026, has impacted approximately 22,000 member-consumer owners (MCOs), prompting emergency measures and public apologies from utility officials.
Technical Complications Trigger Widespread Outage
During a press conference on Tuesday, March 24, Lawyer Rommel Agan, Zamcelco's chief management officer, revealed that the cooperative's 20 Megavolt Ampere (MVA) transformer at the Putik sub-station encountered severe technical issues. "Our contractor encountered technical complications during the scheduled maintenance of a 20MVA power transformer, which affected the Mercedes, Tetuan, Northside, and Zampen feeders," Agan stated.
The maintenance work uncovered an oil leak in the transformer bushings, which was immediately addressed through dismantling and gasket replacement. However, during repairs, air ingress occurred, leading to gas accumulation that triggered the transformer's protection system and caused it to trip. Subsequent testing revealed oil contamination, including moisture and internal residues, necessitating multiple cycles of oil filtration to meet safety standards.
Contingency Measures and Feeder Management
Effective Monday night, March 23, the rotational blackout scheme was activated for the Mercedes, Tetuan, Northside, and Zampen feeders. As part of contingency measures, the Zampen feeder – which serves hospital facilities – has been temporarily connected to a generator at the Putik sub-station to ensure uninterrupted operations. The other affected feeders are being temporarily connected or transferred to other Zamcelco sub-stations.
Agan announced that two power transformers, each with 10MVA capacity, will be brought to the Putik sub-station to replace the failed 20MVA unit. One transformer is currently at the Ayala sub-station, while the other is at the La Paz sub-station. Meanwhile, Zamcelco personnel have begun dismantling the 20MVA Hyosung transformer at Putik.
Long-Term Solutions and Infrastructure Development
Engineer John Rex Palad, network services department manager at Zamcelco, provided updates on longer-term infrastructure projects. The cooperative is in the process of securing a Certificate of Approval to Connect (CATC) from the National Grid Corporation of the Philippines (NGCP) to energize the newly constructed Culianan sub-station. The target energization date is either Friday, March 27, or Saturday, March 28, with approximately 8.5 megawatts of load expected to be transferred to the new facility.
A team from Davao del Sur Electric Cooperative Incorporated (Dasureco) and NGCP is currently assisting Zamcelco with activating the two 10MVA power transformers and expediting the energization of the Culianan sub-station.
Public Apology and Restoration Efforts
Agan offered a sincere apology to all affected consumers for the inconvenience, frustration, and disruption caused by the prolonged power interruption. "No words can fully express the hardship and distress that our affected consumers have experienced during this time. We deeply recognize the impact this situation has had on your daily lives and livelihoods, and we sincerely empathize with the difficulties you have endured," he expressed.
The cooperative is maximizing all available resources to gradually restore and normalize power to the four affected feeders. Officials emphasized their commitment to resolving the situation as quickly as possible while maintaining safety standards.
