Protection relay malfunction causes Mindanao blackouts
by Prix D Banzon
Davao City (19 September) -- It was the abnormal functioning of the Protection Relay, a device that detects occurrence of a trip-off of power supply that caused blackout in southeastern and southwestern Mindanao area.
National Transmission Corporation (TransCo) corporate communication officer Milfrance Capulong disclosed this to Davao business reporters in an interview last Tuesday (Sept. 18).
The two areas suffered total blackout where power was cut on September 17 at 8:19 AM and restored at 4:35 PM of the same day.
Capulong said the equipment even without trip-off, indicated such an occurrence and that they considered was abnormal.
The device is located at the substation in Kibawe, Bukidnon under the supervision of the Network Protection Division and Power System Maintenance Department - North.
Capulong said it took several hours to locate the defect and personnel had to do it manually and upon pinpointing the cause they had to disable that function. The detection of trip off is only part of the multi function that the protection relay does.
Each substation she said must have two protection relays to function among others the occurrence of tripping.
Right now she said the supply of power is back to normal and the protection relay that cause the blackout is being assessed for either repair or replacement if needed.
However Capulong said that the unit is a new one and the concerned personnel is tasked to find out what went wrong.
She said investigation and assessment is ongoing and the necessary measures will be implemented to prevent occurrence of the same although she sad that they have to keep their facilities in tip top condition all the time.
TransCo made seven attempts to restore the power but it succeeded at late afternoon where the supply went back to normal, she said.
The power outage on Monday was the longest in years as the last was in 2003 when towers and transmission lines were bombed causing massive blackouts in Mindanao for a day.
While the long brownout occurred she said the TransCo immediately owned the fault and answered all telephone queries while at the same fielded outgoing calls to inform local government units, key officials, the utilities and the business sector and the public through the media.
The TransCo meanwhile explained that contrary to perception they also suffered damages and losses in power generation estimated at 296 megawatts.
With the inconvenience brought about by the power outage, the public sought refuge to malls like in SM-City where it had its generator-set providing power to the mall from the start of trip off until the power went back.
NCCC Mall however decided to close operation Eriberto Barriga, Jr., director for malls and entertainment said as their generator set was destroyed because of trip off and to avoid further damage they had to stop the mall operation on Monday.
"We incurred significant losses but thankfully it was a Monday and pedestrian traffic was not at its peak," he said.
The Davao Light and Power Company immediately after the power tripped off had to supply priority areas and Capulong said the company can only generate so much supply of its generating set that is why areas like hospitals and banks were served first. (PIA XI) [top]