The maintenance content and steps of low-voltage distribution cabinets:

1: Maintenance should start from the low-voltage side of the transformer. After the power is cut off in the distribution cabinet, clean the dust inside the cabinet, check whether the busbar and down lead connections are good, whether the joint points have heat or discoloration, check whether the cable head and wiring pile head are firm and reliable, check whether the grounding wire is rusted, and whether the wiring pile head is tight. All secondary circuit wiring connections are reliable and the insulation meets the requirements.

2: When checking the drawer type switch, the drawer type 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. Remove dirt from the surface and surroundings of the contactor contacts, check if the contact is intact. If the contact is poor, slightly file the contact surface if necessary. If the contact is severely burned (the contact point is worn to one-third of the original thickness), the contact should be replaced. The power indicator instrument and indicator light are intact.

3: When repairing the capacitor cabinet, the main switch of the capacitor cabinet should be disconnected first. After discharging the capacitors to the ground one by one with a wire of at least 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. Debugging of the indication and automatic compensation parts after closing.

4: Maintenance of circuit breakers in the receiving cabinet and contact cabinet: First disconnect all loads, and then use the handle to shake out the circuit breaker. Tighten the wiring screws again and check if the elasticity of the blade meets the regulations. Check if the arc extinguishing grid is broken or damaged, manually adjust the mechanical interlocking opening and closing to ensure accuracy, check if the contact is in good condition, and if necessary, file the surface of the contact. Check if the internal springs, gaskets, and screws are loose, deformed, or detached.