AC contactor is an automatic control system household appliance which is used to connect or disconnect the main power circuit containing load frequently. AC contactor is used in AC circuit.

The common fault of the iron core of AC contactor is sometimes the excessive noise caused by the iron core. If the working voltage of the coil is not enough, the power supply voltage can be adjusted; if the surface of the moving and static iron cores is in poor contact with each other, the surface can be filed to make them touch each other; if the short-circuit fault ring is broken, the short-circuit fault ring can be removed or welded. The common fault is that the armature doesn't fall down when the power is turned off. This may be because the working pressure between the contact points is too small, and the working pressure of the contact points can be adjusted. If the armature or part of the mechanical equipment is stuck, the blocking material can be removed. There should be a gap of 0.1-0.3mm in the middle column of E-shaped iron core. If the gap subsides due to the damage of iron cores on both sides, the armature will produce "sticking" condition. At this time, the plan of the middle column of E-shaped iron core can be sharpened.

When the coil of AC contactor is overtemperature or damaged, check whether the rated current of the coil is consistent with the power supply voltage. If not, replace the suitable coil. This condition may also be caused by a part of short circuit fault caused by mechanical equipment damage or conductive dust attached to the coil, which should be repaired or replaced and kept clean. It may also be that the actual operating frequency of AC contactor is too high, so the appropriate AC contactor should be removed and replaced. This kind of situation can also be produced when a part of AC contactor fitness exercise is stuck. At this time, it should be cleared immediately.

When the start button is pressed, the armature of AC contactor can not be absorbed, which may be caused by the disconnection or damage of the coil. The coil should be repaired or replaced. It may also be that the armature or mechanical equipment is stuck when it moves, or the mechanical equipment is rusted and tilted. At this time, remove the blocking material, rust, grease or replace the parts.

The contact point of AC contactor will lead to arc welding because of excessive current, invalid arc extinguishing equipment and electric arc caused by breaking power circuit. During maintenance, the cause of electric isolation should be analyzed first, and then the contact point should be repaired or replaced after clearing.

Sometimes the contact can not be closed. At this time, screw out the fixed screw of the arc extinguishing cover, open the arc extinguishing cover, and observe whether the upper and lower contacts of the main contact are seriously ablated. If the damage is serious, the moving contact should be removed for maintenance. The maintenance method is to polish the contact points of the moving and static contacts with sand cloth until the surface is smooth. However, when the thickness of the contact point is 1 / 2 of the original thickness, the contact should be removed and replaced. If the contact is not damaged, check whether the mechanical equipment is stuck or use a multimeter to measure the DC voltage of the coil to see whether the working voltage is too low and whether the electromagnetic induction adsorption force is not enough.