Substation Maintenance

Check whether the flameproof surfaces are in good condition and carry out explosion-proof treatment.
Check whether the line plug is complete, no damage or crack, otherwise change it.
Check whether the load switch is complete, whether the contact is burnt, the insulation parts and the corresponding mechanical mechanism are damaged. If so, replace the damage parts. And if the damage degree is serious, and the whole load switch should be replaced.
Check the power-off button and whether the safety interlock button is intact or damaged.
Check whether the operating mechanism is flexible and reliable.
Check the coil for any burn mark, if it is good we should continue to use.
Check whether the high and low voltage side of the coil is good.
Check whether the blast surface of the transformer box is complete and the roughness is qualified.
With a tramegger, test of high and low pressure coil to ground insulation value, high voltage should be not less than 100 m Ω, and low voltage side is not less than 10 m Ω.
With stand pressure test, give high pressure side with 12000 volt, and there is no breakdown or discharge in one minute, that is considered to be qualified. Give low pressure side with 3000 volts,  and there is no breakdown or discharge in one minute, that is considered to be qualified.

Check if the opening or closing between the front door and the box is flexible, the explosion-proof surface and the explosion-proof clearance are qualified, and make the corresponding treatment.

Voltmeter, ammeter, the front door, lights, feeder switch, light condition and K Ω table, MA table, leakage relay, reset button, compensation button, test button should be in good condition, and if damaged, replace them.

All wiring seats in the left side of the box body should be in good condition, the flared mouth should be in good condition, and the explosion-proof surface and clearance should meet the requirements.

Check if the right side of the box body of automatically switching operation mechanism, the CAM, the hand to the mechanism, the interlocking rod is intact. If damaged, replace them.

The DW - 600 automatic air switch in the shell should be in good condition. If the contact is burned, it should be replaced. If the damage is serious, and the whole switch should be replaced.

The power isolation switch should be in good condition with the external operating handle.

The semiconductor tripping device should work accurately. If the damage is lighter, it should be repaired in the laboratory, and replace it when it is serious.
The leakage relay unit shall be complete and the components shall be reliable. If the parts are damaged, the parts should be replaced. If the damage is serious and the whole unit should be replaced.

Voltage transformer, current transformer, screw type fuse should be in good condition. If they are damaged, we should replace them.

The power transformer should be in good condition without fire damage, and the working voltage data should be correct. If it is damaged, we should replace it.
All electrical interlocking terminals should be in good condition and if it is damaged, we should replace it.

The leakage unit and the overflow display board should be in good condition and reliable.

Carefully check the wiring between the components, ensure there is no error and prevent the damage of the components or personal injury due to faulty wiring.