Daily maintenance and overhaul of distribution cabinet

2025-10-16 15:31:50

Distribution cabinet are high-voltage distribution assemblies assembled according to a certain wiring scheme, involving primary and secondary equipment. As a control and protection system for power plants and substations, it is used for power transformers and high-voltage lines. It is equipped with High-voltage switchgear, protective appliances, inspection and measuring instruments, busbars, insulators, etc.

1. Check the surrounding environment of the Outdoor distribution box, using a thermometer, hygrometer, and recorder to check the ambient temperature of -10. Is it frozen when the temperature is between ° C and+50 ° C and the surrounding humidity is below 90%.

2. Check all Power Distribution Cabinet for abnormal vibrations and sounds.

3. Check if the main circuit voltage of the power supply is normal.

4. Remove the wiring of the frequency converter, short-circuit the terminals R, S, T, U, V, and W together, and measure the insulation resistance between them and the grounding terminal with a DC500V megohmmeter. It should be above 5M ohms, strengthen the fasteners, and observe whether there are signs of heating in the components.

5. Check if the terminal block is damaged, if the conductor is skewed, and if the outer layer of the wire is damaged.

6. Check whether the filtering capacitor leaks liquid and expands. The static capacitance measured with a capacity measuring device should be above 85% of the rated capacity; Check if there is a "Be, Be" sound in the relay, if the contacts are rough or broken; Check if there are cracks in the insulation material of the resistor and confirm if there are any broken wires.

7. Check whether the output voltage between each phase is balanced during the operation of the frequency converter; Conduct sequential protection tests on actions to display whether the protection circuit is abnormal.

8. Check if there are any abnormal vibrations or sounds in the cooling system, and if the connecting components are loose.