Check the external conditions, whether the switch is fastened and the operating mechanism is flexible, and adjust if necessary.
Inspect and repair contacts to remove burn marks.
Check and adjust the contact tightness of the moving and static contacts, and check whether the three phases are in contact at the same time, and adjust if necessary.
Replace the damaged arc extinguishing device and check whether there is a gap between the arc extinguishing insulation. Replace cracked and damaged insulators . Wipe the high-voltage load switch clean.
Check whether the ground is complete and reliable.
After the high-voltage load switch is installed or repaired, a speed test should be carried out. It is required that the opening speed should be (3.6 ± 0.2) m / s and the closing speed should be (4 ± 0.4) m / s. If the breaking speed cannot meet the requirements, the opening spring can be adjusted to achieve the closing speed. The gasket inside the tube can be used to achieve the closing speed.
After overhaul of the high voltage load switch, insulation resistance measurement, AC withstand voltage test, contact contact resistance measurement, and thermal contact test are required. After passing the test, it can be put into operation.