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What are the Operation Precautions for HV switchgears?

Jan 11, 2017


Operation Precautions for HV switchgears

1. The check before power supply should be complete and careful. Operate after all conditions meet the requirement. There should be written record for maintenance work.

2. Before the operation whether to make the switch from test position to working position or from working position to test position, check and make sure the switch is at Open position and the status indicator and switch body mechanical position both show Open position and then do the operation.

3. The status of grounding  disconnecting switch  should  be consistent with status indicator, operation hole interlock device and actual position of back door. The actual position can not be decided only depend on the status indicator.

4. The secondary plug can be put into  operation or detached when switch is at test position. When it is put into operation, the contact should be well and when is detached, it should be fixed at the specified position.

5. Put secondary plug, instrument, control, device and AC power into service before power supply, for power cut-off , it is reversed.

6. Before operate switch and grouding disconnecting switch, supply power to instrument, control, device, AC power to make solenoid interlock device worked reliably to prevent solenoid interlock being out of order.

7. When transfer the control mode of switch, first should make sure to prevent misoperation of opening/closing switch.

8. When do the operation on switch, grounding disconnecting switch and find the operation is not flexible and jammed, cannot operate forcely. Do complete check again and inform maintenance people after make sure there is no problem. When do maintenance work, avoid damaging interlock device. Assure the interlock device is well used after maintenance and then operate.

9. For the operation to make switch at  maintenance position or test position , first should regulate the height of trolley to make sure it is aligned with switchgear and is fixed with the cabinet body. After push switch to test position, make sure the switch is fixed well with cabinet body to prevent it from falling down when taking trolley away.

10. Measure the insulation resistance from the back door. Do not open back door when there is no need to measure insulation resistance. Verify the name of  equipment carefully after open the back door.

11. If need operation on grounding disconnecting switch after the back door is opened, use tools to withstand the interlock device of the door and then open/close grounding disconnecting switch.

12. When there is requirement for switch maintenance, it is allowed to pull the switch to maintenance position.

13. For the operation on mechanical part of equipment, only need to rotate switch to test position and there is no other operation.

14. When maintain motor or cable, rotate switch to test position, close grounding disconnecting switch, put the responding caution plate and there is no other operation.

15. When maintain protection and secondary circuit, rotate switch to test position, close grounding disconnecting switch, open every secondary switch inside the cabinet and put responding caution plate.

16. When finish the electrical maintenance, take back the safety measures. If the safety measures cannot be taken back for other work, should write down the reasons on maintenance work permit and log sheet.

17.  Write down clearly about grounding line installation or removing, opening or closing grounding disconnecting switch on log sheet.

18. For the installed grounding line and closed grounding disconnecting switch at site, write detailed record at the operation mode column.