The open circuit coil of the plastic case circuit breaker is burnt out

1, open solenoid mechanical equipment failure. When the coil is loose, the electromagnet core moves when the plastic case circuit breaker is disconnected, the core gets stuck and the coil burns out. May also be due to the absence of iron core of the active learning travel time is short, when the power system to open the control circuit is connected, the iron core will not open the tripping mechanism by itself, so that the coil for a long time in the energized, resulting in the impact of burning.

2. The dead point adjustment is not properly managed and the work of the mechanism cannot be carried out to get released in time, resulting in overloading of the coil and burning of the dividing coil.

3. If the disconnecting state of the auxiliary switch is improperly adjusted and the auxiliary switch exceeds the travel range of the disconnecting state, the auxiliary switch will not switch open normally and the disconnecting coil will burn up.

4. Improper use of the auxiliary switch. When the closing time of the circuit breaker is very short, much less than the opening time of the circuit breaker, the circuit breaker cannot be closed in time and the circuit breaker is in a closed state. Conversely, due to the small gap between the electrostatic insulation and the dynamic electrical insulation of the auxiliary switch, an arc is often generated, leading to the burning of the auxiliary switch contacts and consequently of the coil.

5. When the parallel relay in the device fails or the parallel auxiliary switch contact coupling is large, the parallel cannot be withdrawn in time and the parallel coil is energised for a long time, resulting in burnout.

6. When the circuit of the switch coil carries out the insulation ability to reduce, or the circuit resistance is too small, it will lead to a switch system circuit working voltage decay, resulting in different voltage can not reach the voltage value of the coil switch, resulting in some switch coil charging learning time is too long, resulting in burned coils.

MCCB closing coil burnout causes

1. Due to the mismatch of the working mechanism of the circuit breaker, the wire inside the circuit breaker body cannot open the circuit breaker, the drive linkage is poorly blocked and the protection locking interlocking mechanism does not operate properly, resulting in the circuit breaker not being able to open, leading to the closing coil being burnt due to overloading of the closing iron core.

2. When the protection control device gives the disconnection command, the switching relay in the device fails or the operating travel of the auxiliary switch of the door control circuit is large, making it impossible to withdraw the disconnection command in time. This results in the switch coil being charged and burning for a long time.

3. When the circuit breaker is closed, due to a large closing current generation, the control system circuit cannot carry out direct cost control of the closing coil, but can only be connected to the closing coil through the indirect network of the closing contactor, when the closing contactor fails, it cannot be disconnected in time, resulting in the closing coil being opened for too long a learning time and burning the coil.

How to prevent the coil from burning up

1. Adjust the position of the auxiliary switch correctly.

2. Fix the switch coil and check if the switch coil core is stuck.

3. Correctly adjust the linkage mechanism of the circuit breaker during maintenance.

4. Strengthen the inspection and maintenance of the AC contactor.