Troubleshooting Method for AC Contactor of Crane

Terms of settlement:

(1)Reduce the pressure of movable contact spring;

(2) Cleaning the dirt on the working surface of the magnetic conductor;

(3) Adjusting the position of the magnetic conductor;

(4) Remove additional friction.

1. Delayed suction and closure

Causes of failure:

(1)The movable part of the magnetic conductor is far from the stationary part.

(2) The upper part of the bottom plate of the instrument protrudes from the lower part.

Terms of settlement:

(1) shorten the distance between the two parts;

(2) Vertical devices.

2. The magnet does not drop and release delayedly when the power is cut off; the contact is overheated.

Causes of failure:

(1) The contact pressure is insufficient.

(2) Dirty core working face;

(3) Contact burning and melting.

Terms of settlement:
Increase spring pressure of contact;
Eliminate core dirt;
Clean up contacts.

3. Contactors often turn off during crane operation

Causes of failure:

(1)The contact pressure is insufficient.

(2) Contacts burned out;

(3) Overload and overcurrent;

(4) Track unevenness affects sliding line contact

Terms of settlement:

(1)Increase spring pressure of contact;

(2) Repair light contacts and replace them;

(3) Load reduction;
      Repair track.