Blackout hits Bohol anew
TAGBILARAN CITY, Bohol, Dec. 18 (PNA) -- Hitches in Leyte grid clutched anew the entire island of Bohol to another total power outage on Saturday.
Bohol sub-stations of National Grid Corporation of the Philippines (NGCP) dried up again of power supply twice yesterday when the Ormoc-Maasin 138kV Line 2 tripped anew.
The tripping in the Leyte side of the Leyte-Bohol power grid caused supply interruption at 9:56 a.m. to 10:31 a.m. and at 11:18 a.m. to 6:00 p.m. Saturday.
NGCP-Leyte had to send a line inspection team in a chopper to conduct aerial inspection.
The chopper team reinforced the ground patrol team that went out tracing the cause the entire afternoon.
The chopper team had to wait until later in the afternoon as the winds prevented it from flying at first attempt.
Betty Martinez, spokesperson for NGCP-Visayas, explained that NGCP actually sent three patrolling teams along the 114-kilometer Ormoc-Maasin Line 2.
They surveyed the area from Structure 180 to Structure 220. The first team took charge of Structure No. 180, while the second team proceeded to Structure 220, and the third team surveyed the middle part.
While line patrol had been undertaken in Leyte, business operations in most parts of Bohol halted on another Saturday power glitch.
Most common cause of unscheduled power interruptions is “vegetation” such as coconut fronds, branches of trees, or any even banana leaves touching the transmission lines. This causes load interruptions.
Except for incidents like this, NGCP undertakes necessary power shutdown from time to time to facilitate maintenance routines usually on Saturdays.
Just within the month, Bohol had experienced one scheduled power blackout and a major unscheduled power shutdown.
The scheduled 13-hour power shutdown on Dec. 3 from 4:00 a.m. to 5:00 p.m. stretched to 20 hours and a half and NGCP managed to restore power only at 12:27 a.m. on December 4, attributing it to bad weather that made it difficult for the NGCP linemen and engineers to undertake the procedure.
An unscheduled power interruption affecting the entire Bohol followed on the same day at 1:21 p.m. and NGCP restored power at 2:02 p.m., attributing it to another tripping of the 138kV Ormoc-Maasin Line 2.
NGCP qualified the December 3 scheduled power shutdown as necessary in relation to line upgrading activity as a second line, or Line 2, has been added to the Leyte-Bohol grid that supplies electricity to Bohol through submarine cables.
Line 2 has been in place to ensure continuous power supply in the future.
In most cases, linemen have to dodge with the weather in Leyte that is prone to typhoons and other weather systems.
On November 18, tripping in Ormoc-Maasin line caused an almost one-hour blackout in Bohol. The unscheduled power interruption hit Bohol from 9:51 p.m. to 10:47 p.m.
NGCP traced the sudden shutdown of power supply to the tripping of the 138-kilovolt Ormoc-Maasin line in Leyte which affected the operation of all the three power distribution utilities in Bohol- -Bohol Light Company, Inc., Boheco I and Boheco II.
On Sept. 3, NGCP also conducted maintenance activities in some parts of Bohol affecting only BOHECO II service area at 5:00 a.m. - 6:00 a.m. and at 5:00 p.m. - 6:00 p.m.
The maintenance activities were undertaken along the 69kV Ubay-Alicia-Garcia line.
Another round of maintenance activities were undertaken on Sept. 1 at 5-6 a.m. and at 5-6 p.m., affecting only the BLCI Dampas sub-station, BOHECO I Loay and Panglao substations and BOHECO II Garcia Feeder.
The maintenance activities were undertaken along the 69kV Tagbilaran-Garcia line.
On Aug. 6, power interruption was scheduled, affecting BOHECO II Guindulman and Alicia substations at 5:00 a.m. - 6:00 a.m. and at 5:00 p.m. - 6:00 p.m., to facilitate maintenance works along the 69kV Ubay-Alicia-Garcia line.
Another blackout was experienced on June 11 from 5:00 a.m. to 6:00 p.m. when NGCP transferred wires of Tower 70 along the 138-kilovolt Ormoc-Maasin Line 1 to a temporary structure to facilitate repairs on the tower, in addition to project-related and other synchronized maintenance activities.
In barely a month, another blackout followed on July 9 affecting the entire Bohol from at 5:00 a.m. to 6:00 p.m. due to shutdown of the 138-kilovolt Ormoc-Maasin line to facilitate return of wires from Emergency Restoration System (ERS) structure the repaired Tower 70 in Albuera, Leyte.
Another 13-hour blackout was experienced on March 5 from 5:00 a.m. to 8:00 p.m. when NGCP had to shutdown the 138-kilovolt Maasin-Ubay submarine cable line for its annual preventive maintenance including the 100-megavolt-ampere transformer and other equipment at Ubay Substation.
It was actually another instance when NGCP had breached its original target of supposedly containing the power interruption from 5:00 a.m. to 6:00 p.m. on a Saturday.
By the time households were expecting the return of power supply at 6:00 p.m., the NGCP issued another advisory informing that the power interruption would be extended up to 7:00 p.m. as they were still working on the line configuration from Corella-Tagbilaran and Tagbilaran 69kV line sections.
By 7:00 p.m., the NGCP issued another advisory informing that the power interruption would further be extended up to 8:00 p.m.
NGCP explained that as of 7:00 p.m., line configuration from Corella-Tagbilaran and Tagbilaran 69kV line sections had been completed already, but the lines could not be re-energized because of a breaker problem on the part of BLCI.
The March 5 blackout was the second power interruption in 15 days and the first to cover entire Bohol this year.
Power interruptions in parts of Bohol, affecting only consumers of BOHECO II, were experienced on February 18.
The power interruptions then only spanned from 6:00 a.m. - 7:00 a.m. and 4:00 p.m. - 5:00 p.m.
It was only due to maintenance works along the 69-kV Ubay-Alicia-Garcia line.(PNA)