Rotting air break switch extends Sunday brownout

By Francis Allan L. Angelo

 

The maintenance work on the Mandurriao substation in Iloilo City was supposed to end and restore power supply an hour ahead of the schedule if not for the rotting air break switch that extended the outage by two hours.

MORE Power, the distribution utility in Iloilo City, scheduled the 13-hour brownout (4 am to 5 pm) in Mandurriao district Sunday to give way to much-needed corrective and rehabilitation works.

The maintenance works were finished as early as 4 pm and MORE Power attempted to restore supply from the 69kv sub-transmission line at Brgy. Baldoza, La Paz.

The sub-transmission line transmits power from Panay Energy Development Corp and Panay Power Corporation at Brgy. Ingore, La Paz to the substation in Brgy. Bolilao, Mandurriao.

But the supply restoration failed due to a misalignment in the Disconnect Switch of the sub-transmission line.

Further investigation by MORE Power’s Network Operations Team indicated that a dilapidated Air Break Switch caused the problem.

An “air break switch’ is a switchgear device that uses air as the dielectric or insulating material. Air Break Switches (ABS) are widely installed throughout distribution networks for use as both isolation or switching points.

Air Break Switch Disconnectors are a vital part of any overhead line network, providing crucial points of isolation.

Most overhead line networks are designed so that when a fault occurs or maintenance work needs to be carried out it is relatively simple, by means of a systematic series of switching operations, to isolate a certain section of the overhead line.

The MORE Power team said they discovered that the “blade” or contact arm of the air break switch was in disrepair, rusty, and was misaligned. These are indications of poor or lack of proper maintenance.

Since the switch was already in disrepair, MORE Power decided to install “bypass” connections in three lines in order to supply power to Mandurriao. The installation lasted for an hour and a half, thus extending the power outage in Mandurriao by another two hours.

Power supply was restored to Mandurriao past 7 pm Sunday.

Because of the incident, MORE Power said it will conduct thermal scanning and evaluation of all disconnect switches in the city as it believes that there are more dilapidated switches in the distribution system.

It is possible that these switches will conk out and cause more widespread outages in the future if these are not replaced.

Sunday’s maintenance works at Mandurriao was the last on the five substations in the city. The other substations are in Jaro, Lapaz, City Proper, and Molo.

The corrective works were meant to increase the efficiency of the facilities in delivering power to the consumers.

“We want everyone to understand that preventive maintenance work on our substations and distribution network are critical part in ensuring their optimal performance in the long term. After continual use, all machines will begin to deteriorate in functionality, making them less efficient and less reliable which is why this preventive maintenance work is essential to ensure that they will be working efficiently and safely,” MORE Power said in a statement.

With all the substations now primed and powered up, the firm assured consumers that the chance of emergency or unnecessary repairs are now reduced as the maintenance efforts basically lowered its chance from happening.

“Be assured that this effort is a cornerstone of our strategy to provide the Ilonggos access to affordable, reliable, and sustainable energy.”