A High-voltage Disconnect Switch Malfunction Prolonged The Power Outage.

During a power system maintenance operation, if the hv isolator operating mechanism jams or the contacts make poor contact, the power outage process cannot be completed as planned, delaying power restoration. Several factors can contribute to this situation.

Some faults originate from aging of the hv isolator switch switch body, corrosion of mechanical parts, or lubrication failure, which can hinder the normal closing/opening of the switch. Poor contact or improper adjustment of the contacts may cause overheating and increased contact resistance, leading to isolation failure.

If the high voltage electrical isolator switch is put back into operation after a long period of inactivity, its mechanical parts may malfunction due to oxidation, dried-out lubricant, or contact corrosion.

When the isolator high voltage switch cannot be fully closed or opened, maintenance personnel cannot determine the power disconnection or restoration status. To ensure safety and equipment integrity, maintenance and power restoration time are often extended, delaying the overall power grid restoration process.