Reasons for Burnout of Opening and Closing Coils of Vacuum Circuit Breakers

The common reasons for the burnout of the opening and closing coil of the vacuum circuit breaker are as follows:

1. There is a problem with the quality of the opening and closing coil, and the resistance, wire and insulation cannot meet the standard;

2. There is a problem with the operating mechanism, and the operating power is too large, so that the opening and closing coil cannot be opened, and the coil works for a long time;

3. The circuit breaker body is stuck, which makes the operating mechanism unable to work normally, and the coil works for a long time;

4. The working power is not enough, such as low voltage;

5. The AC coil works with DC power supply;

So how to prevent the opening coil of the vacuum circuit breaker from being burned?

The main task is to provide the basis for fault diagnosis and analysis. After the vacuum circuit breaker is put into operation, regular inspections should be carried out. The vacuum circuit breakers used in the substations or power plants on duty will be inspected at least once a day. The unattended substations can be determined according to the specific situation. Usually Not less than once a month. The inspection items are as follows:
1. Whether the indication of the opening and closing indicators is correct, and its indication should be consistent with the actual operating conditions at that time;

2. Whether the support insulator is cracked or damaged, and whether the surface is smooth or not;

3. Whether there is any abnormality in the vacuum interrupter (including whether there is abnormal sound), if it is a glass shell, it can be observed whether the color of the shielding cover has changed significantly;

4. Whether the metal frame or base is severely corroded and deformed;

5. Whether the connecting bolts in the observable part are loose or not, and whether the shaft pins are falling off or deformed;

6. Whether the grounding is good;

7. Whether there is overheating in the contact part of the lead wire or the part with the temperature-indicating wax sheet, and whether the lead wire slip is moderate. The above preventive work can be done, which can greatly reduce the phenomenon of the vacuum circuit breaker opening coil being burned;