Causes of AC contactor coil failure

    AC contactor is a kind of electrical switch used to automatically turn on or off the high current circuit. It can turn on or off the AC circuit frequently and realize remote control. Its main control object is the motor, which can also be used for other loads. It has the characteristics of large control volume, strong load working capacity, long life, simple and economic equipment, so it is widely used in electrical control. Obviously, with its special working environment, AC contactor will inevitably produce various kinds of faults. If it can not detect and remove the faults immediately and effectively, it will certainly cause harm to the normal work of electrical equipment, so as to cause the adverse effect of electrical equipment burning.

    In the application of AC contactors, the coil burnout is one of the common faults, and there are many reasons for the coil burnout. Shanghai Changcheng, the manufacturer of AC contactors, explains in detail the reasons for the coil burnout, for example, the power supply voltage is too high. If it exceeds 110% of the rated current, it may burn the coil. In addition, if the power supply voltage is too low, 85% of the rated value may burn the contactor coil, which is caused by the failure of the contactor armature to close, the small reactance value of the coil control circuit and the excessive current. In addition, the power frequency does not conform to the rated value, the mechanical part is blocked, the magnetic gap is too large due to the uneven pole surface of the iron core, and the environmental factors such as abnormal ventilation, too wet and too high ambient temperature all cause such faults. Coil disconnection fault is often caused by overheating and burning of coil, or by damage caused by external force.

    For different reasons, different countermeasures should be adopted. In case of abnormal coil failure, the coil of the same model can be replaced. If the iron core is free of dirt or uneven polar surface, the polar surface can be removed or replaced according to the situation.