THE Zamboanga City Electric Cooperative (Zamcelco) has adopted rotational blackout scheme on four affected feeders after its 20 Megavolt Ampere (MVA) transformer encountered technical complications during the scheduled maintenance on Sunday, March 22, 2026.
Included in the rotational blackout scheme effective Monday night, March 23, are the Mercedes, Tetuan, Northside, and Zampen feeders with around 22,000 member-consumer owners (MCOs).
Lawyer Rommel Agan, Zamcelco chief management officer, said that as part of their contingency measures, Zampen, being a hospital facility, is temporarily connected to a generator at Putik sub-station set to ensure uninterrupted operations.
The other affected feeders are being temporarily connected or transferred to other sub-stations of Zamcelco.
Mercedes, Tetuan, Northside, and Zampen feeders are originally connected to Putik sub-station of Zamcelco, where the 20MVA power transformer is located.
"Our contractor encountered technical complications during the scheduled maintenance of a 20MVA power transformer, which affected the Mercedes, Tetuan, Northside, and Zampen feeders," Agan said in a press conference Tuesday afternoon, March 24.
Agan said that during the maintenance activity, an oil leak in the transformer bushings was identified and immediately addressed through dismantling and gasket replacement.
However, in the course of the repair, air ingress occurred, resulting in gas accumulation that triggered the transformer's protection system and caused it to trip.
Subsequent testing revealed oil contamination, including the presence of moisture and internal residues, which necessitated multiple cycles of oil filtration to ensure that the transformer meets all operational safety and quality standards. Hence, the longer cause of the longer power interruption.
Agan said two power transformers with 10MVA capacity each will brought to Putik sub-station to replace the 20MVA transformer. One of the two transformers is in Ayala sub-station and the other is in La Paz sub-station.
In the meantime, Zamcelco personnel have started dismantling the 20MVA Hyosung transformer in Putik sub-station.
Engineer John Rex Palad, network services department manager of Zamcelo, said they are in the process of securing 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 date for energization of Culianan sub-station is either on Friday, March 27, or on Saturday, March 28. Approximately 8.5 megawatts of load will be transferred to the sub-station.
A team from Davao del Sur Electric Cooperative Incorporated (Dasureco) and NGCP are currently assisting Zamcelco for the activation of the two units of 10MVA power transformer, as well as well as for the immediate energization of the Culianan sub-station.
Meanwhile, Agan sincerely apologized to all Zamcelco valued MCOs 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," Agan said.
He said they are maximizing available resources to gradually restore and normalize power to four affected feeders. (SunStar Zamboanga)