Cable failure triggers 3-hour islandwide power outage

A high voltage cable failure at Power Plant 4 in Puerto Rico, Saipan, last Friday afternoon triggered an islandwide power outage.

The outage also interrupted water service to China Town, Upper Mihaville Estate in Garapan, and in As Falipe, according to the Commonwealth Utilities Corp.

A CUC Customer Call Center staff told Saipan Tribune that the outage lasted three hours.

In a public advisory, CUC executive director Gary P. Camacho said that CUC experienced an islandwide power outage last Friday at 1:37pm due to the failure of a high voltage cable at Power Plant 4, which cut off the power supply to the power plant. As a result, it tripped Kiya 2 and Feeders 4 and 7.

Camacho said this triggered the protective devices at Power Plant 1 in Lower Base, tripping the remaining feeders and resulting in the islandwide power outage. CUC then did repairs to energize the power system.

As of Friday at 2:40pm, feeders 2, 3, and 4 have been restored.

In a separate advisory, Camacho said due to the power interruption, water pumps were unable to pump water into the water tanks throughout the island, thereby limiting available water supply to meet consumer demand.

He said the volume of the tanks should reach critical level late Friday night.

CUC then expected water services to return to normal by 6am last Saturday.

In his recent report to CUC board, Camacho disclosed that for the month of June this year, a total of 17 scheduled and unscheduled outages were recorded and accounted for approximately 45 hours of lost revenue.

Camacho said of the 17 outages, eight scheduled outages were made and accounted for 35 hours of lost revenue.

He said all eight scheduled outages were a result of task performed for maintenance purposes and CUC’s pole replacement tasks.

He said the monthly average for scheduled outages in 2017 was five outage events, with a total duration of 19 hours.

Camacho said in an effort to minimize the revenue loss from scheduled power outages, engineers are utilizing isolation devices such as air break switches, jumper cables, and transformer cut-outs to isolate and minimize areas with lost power service.

He said a total of nine unscheduled outages were recorded and resulted in 10 hours of lost revenue.

He said the unscheduled outages were a combination of feeder and later ourtages and were a result of unregulated overcurrent faults.

CUC recorded that the monthly average for unscheduled outages in 2017 was six outage events with a total duration of eight hours.