Davao Light and Power Company, one of the Philippines’ largest electric distribution utilities, has reported reliability improvements following a multi-year effort to modernize portions of its distribution network and reduce customer outages.

The utility serves Davao City and the surrounding Davao region, an area characterized by a tropical rainforest climate with high temperatures and frequent rainfall throughout the year. Severe weather, animal contacts and vegetation-related issues have historically contributed to temporary faults on lateral lines and at the edges of the distribution system, resulting in service interruptions for customers.

Davao City has also experienced rapid economic growth, including population increases, new business development and construction of high-rise buildings. The utility said the growing demand for reliable electricity placed additional pressure on the distribution system and heightened the impact of even brief outages on commercial and industrial activity.

As part of a broader reliability improvement program, Davao Light evaluated ways to reduce sustained outages caused by temporary faults. Under its previous protection approach, fuse operations often required crews to locate and replace damaged fuses before service could be restored. The utility reported that fault location and fuse replacement could take several hours and, in some cases, up to half a day because of traffic and access challenges.

At the time, Davao Light reported a System Average Interruption Duration Index (SAIDI) of 430 minutes and a System Average Interruption Frequency Index (SAIFI) of 10.49.

The utility launched a grid reliability initiative focused on supporting growing customer demand while reducing service disruptions. As part of the initiative, Davao Light deployed TripSaver II Cutout-Mounted Reclosers from S&C Electric Company. The cutout-mounted devices are designed to automatically restore power following temporary faults on lateral lines, reducing sustained customer interruptions and the need for manual fuse replacement.

The utility initially deployed three units in a pilot project and later expanded the trial with 20 additional devices at locations that experienced frequent temporary faults.

Following the pilot, Davao Light identified three locations on its distribution network where outages occurred more frequently and installed the devices. According to the utility, the installations cleared 32 temporary faults within one year that otherwise could have resulted in sustained customer interruptions. The locations recorded 16, 12 and four temporary fault events, respectively.

Over the next six years, Davao Light expanded its reliability improvement efforts across the network. In addition to lateral reclosing, the utility implemented feeder upgrades, three-phase reclosing and sectionalizing, covered conductor installations and other reliability measures.

During that period, the utility reported improvements in key reliability metrics. SAIFI declined from 10.49 to 3.40, while SAIDI decreased from 430 minutes to 260 minutes.

Based on the results, Davao Light expanded its deployment of cutout-mounted reclosers and has installed approximately 250 units across its distribution system as part of its ongoing reliability strategy.