AS PART of its continuing efforts to minimize power line shutdown and efficiently serve customers, power grid operator National Grid Corporation of the Philippines (NGCP) has been deploying its linemen to conduct hotline or live line maintenance work.
Hotline or live line maintenance work is a proven technology in the electric transmission industry that allows the safe repair of high-voltage lines without shutting them down. In doing so, electricity consumers do not experience service interruptions while NGCP works on the energized lines.
One such activity was recently conducted along NGCP’s Pagadian-San Miguel 69-kV line to replace old cross-arm and insulator strings of transmission structures located at Tikwad, Dumalinao, Zamboanga del Sur.
A day before the activity, a pre-maintenance meeting was held at Aurora Substation in Zamboanga. The said meeting was attended by the Mindanao Operation and Maintenance District 1 line gang, the district’s safety engineer, and a representative from the local distribution utility ZAMSURECO 1.
An hour before the hotline maintenance work, a tool box meeting for the line personnel of both NGCP and ZAMSURECO 1 was conducted to discuss specific assignments per lineman involved and to reiterate safety precautionary measures in conducting maintenance work. Tools and equipment were also inspected and ensured in good condition.
The actual hotline activity, witnessed by 18 personnel from ZAMSURECO 1, was completed in just two and a half hours.
Edinower Cabanos, Chief Line Engineer, Rommel Manogura, Line Engineer, Marlou Vargas, Safety Engineer, and a representative from the Security Division were also present during the hotline maintenance.
NGCP regularly trains linemen and technical personnel on transmission line maintenance planning and implementation, restoration of lines and equipment, and ensuring safety at the workplace.
Trained "hotliners" regularly go out to the field to eliminate power line "hot spots" and conduct emergency liveline repairs. A hot spot is an abnormal heating of components or parts of transmission line due to lose connections between points where electricity flows. The abnormal heat produced may cause lines to trip and cause power interruptions. This is where linemen step in to make the necessary remedies.
NGCP is a privately owned corporation in charge of operating, maintaining, and developing the country’s power grid. It transmits high-voltage electricity through “power superhighways” that include the interconnected system of transmission lines, towers, substations, and related assets. The consortium, which holds the 25-year concession contract to operate the country's power transmission network, is comprised of Monte Oro Grid Resources Corp. led by Henry Sy, Jr., Calaca High Power Corporation led by Robert Coyiuto, Jr., and the State Grid Corporation of China (SGCC) as technical partner.
NGCP’s regular maintenance activities, expansion, and upgrading projects aim to enhance the reliability and quality of electricity delivered to grid-connected customers like generators, distributors, and large industries.
NGCP’s hotline or live line maintenance involves repairing the transmission line while it is still energized. The procedure is used to avoid loss of supply while fixing a transmission line component.