Detailed Explanation Of Common Faults And Measures For High-voltage Isolating Switches

Failure of refusal to close and countermeasures:

high voltage isolator with higher voltage level is operated by electric operating mechanism. When high voltage isolator switch of electric operating mechanism refuses to close, we should pay attention to whether the contactor is working, whether the motor is rotating, and the operation of the transmission mechanism, so as to distinguish the scope of the fault and report to the dispatcher.

(1) If the contactor does not work, it may be a problem with the control circuit. Solution: First check whether the equipment number and operation sequence are correct. If so, the operation circuit is locked by the anti-error locking circuit. The wrong operation should be corrected immediately. Then check whether the operating power supply is normal, whether the fuse is blown or the contact is poor. Continue to operate after normal treatment. If there is no above problem, check the blocked point in the circuit. Continue to operate after normal treatment.

(2) If the contactor has worked, the problem may be contactor jamming or poor contact, or it may be a problem with the motor. The voltage on the motor terminal should be further checked. If the voltage is abnormal, it proves that it is a problem with the contactor, otherwise it is a problem with the motor.

(3) If the motor is rotating and the mechanism cannot be closed due to mechanical jamming, the operation should be suspended. First check grounding hv isolator to see if it is fully opened. After it is fully opened, you can continue to operate.
If there is no problem, check whether the motor is missing a phase. After the three-phase power supply returns to normal, you can continue to operate. If it is not a phase loss problem, you can perform manual operation to check the mechanical jamming part. If it can be eliminated, you can continue to operate. If it still cannot be solved, you should adjust the operation mode to restore power supply first, and then report to the superior. When the power is off, the maintenance personnel will handle it.
(1) First check whether the equipment number and operation procedure are correct, and check whether the circuit breaker is in the disconnected position.
(2) If there is no problem, check whether hv isolator switch is fully opened. After it is fully opened, you can continue to operate.
(3) If there is no problem, check the mechanical jamming part. If it is a mechanism failure and lack of lubricating oil, you can add oil, turn it a few more times, and then close it. If it is a problem with the transmission part and cannot be handled for the time being, you should adjust the operation mode to restore power supply first, and then report to the superior. When the power is off, the maintenance personnel will handle it.
The inspection and treatment methods of high voltage electrical isolator refusal to open fault are basically the same as those of isolator high voltage refusal to close fault and treatment methods, except that when it cannot be opened manually, it is not allowed to be opened forcibly. The operation mode should be adjusted and the fault isolation switch should be taken out of operation for inspection and maintenance.