How to repair and maintain Low-voltage switchgear

2025-10-16 11:05:44

Maintenance should start from the low voltage side of the transformer. After the Low-voltage switchgear is powered off, clean the dust in the cabinet, check whether the busbar and down lead connections are good, whether the joint points are heated or discolored, check whether the cable head and wiring pile head are firm and reliable, check whether the grounding wire is corroded, and whether the wiring pile head is tightened. All secondary circuit wiring connections are reliable and the insulation meets the requirements.

When checking the drawer switch, the drawer Switch cabinet should be flexible when pushed in or pulled out, and the mechanical locking should be reliable. Check if the automatic air switch operating mechanism on the drawer cabinet is in place and if the wiring screws are tightened. Clean the surface and surrounding dirt of the contactor contacts, check whether the contact of the contactor contacts is intact. If the contact is poor, the contact surface can be slightly filed if necessary. If the contact is severely eroded (the contact point is worn to 1/3 of its original thickness), the contact should be replaced. The power indicator instrument and indicator light are intact.

When repairing Power switchgear, the main switch of the Low voltage comprehensive distribution box should be disconnected first. After discharging the capacitors to the ground one by one with a wire of more than 10mm2, the appearance of the shell should be checked and there should be no oil leakage. If the capacitor shell expands, it should be dealt with in a timely manner, and the discharge device, control circuit wiring screws, and grounding device should be replaced. After closing, debug the indicator and automatic compensation parts.

Maintenance of circuit breakers in the power receiving cabinet and contact cabinet: First disconnect all loads, then use a handle to shake out the circuit breaker. Re tighten the wiring screws and check if the elasticity of the blade meets the requirements. Check if the arc extinguishing barrier is broken or damaged, manually adjust the mechanical interlock for accurate opening and closing, check if the contact is in good contact, file the contact surface if necessary, and inspect the internal springs, washers, and screws for looseness, deformation, and detachment.