How to deal with the inability of intelligent circuit breakers to close? There are many reasons why circuit breakers cannot close, such as improper operation during closing, inadequate voltage quality of the closing busbar, control circuit disconnection, mechanical faults, etc. Overall, it refers to faults in the electrical secondary circuit, mechanical faults in switches and operating mechanisms.
Once the circuit breaker fails to close, the on duty personnel must first distinguish whether it is an electrical secondary circuit fault or a mechanical failure of the operating mechanism. Distinguishing criteria: indication of traffic lights, changes in flashing, and actions of closing contactors and closing iron cores.
(1) When the control switch is turned to the "closed" position, the traffic lights remain unchanged, the green light is still flashing, the red light is not on, the closing ammeter does not shake, and the horn sounds.
☑ In this case, it can be seen that the operating mechanism is not functioning, and the problem is mainly with the return intelligent residual current circuit breaker, which is due to the melting of the closing fuse or poor contact.
(2) When the control switch is turned to the "closed" position, the green light goes out and the red light does not light up.
☑ When the control switch returns to the "closed" position, the traffic lights do not light up and an accident audio signal appears. At this point, it indicates that the switch is completely not turned off. It may be due to the fuse melting or poor contact during operation.
☑ When there is no reported accident sound signal, the closing ammeter shows shaking, there is also load current on the line, and the mechanical opening and closing pointer is also in the "closed" position, it indicates that the switch is in the "closed" position.
☑ At this time, please check for poor contact of the light bulb, lamp holder, operating fuse, and normally open auxiliary contacts of the circuit breaker. If the above situation occurs, the staff should immediately disconnect the circuit breaker, eliminate the fault, and then close it.
(3) When the control switch is turned to the "closed" position, the green light will turn off and then light up or flash again.
☑ The circuit breaker closing ammeter has oscillations due to two reasons:
1, The voltage of the closing power supply is too low, and the operating mechanism is unable to lift the switch lifting rod, resulting in incomplete action of the transmission mechanism.
2, Improper adjustment of operating mechanism. For example, if the closing iron core exceeds the distance or the buffer gap is insufficient, and the top rod of the closing iron core is not adjusted properly.
If this situation occurs, professional maintenance personnel should be hired for repair.