Contactor daily maintenance method - Solutions - Huaqiang Electronic Network

Photocoupler

Frequent or regular inspection of the operation of the contactor and the necessary repairs are important measures to ensure reliable operation and prolong its life. When checking and repairing, first disconnect the power supply, follow the steps below.

1, visual inspection

To remove dust, wipe off the oil with a small amount of gasoline on a cotton cloth, and then wipe it with a cloth;

Tighten the screws of all crimping wires to prevent loosening and heat generation.

2, contact system inspection

1) Check if the dynamic and static contacts are aligned, whether the three phases are closed at the same time, and adjust the contact springs to make the three phases consistent.

2) Shake the interphase insulation resistance value. Using a 500v shaker, the phase resistance should not be less than 10 megohms.

3) When the thickness of the contact wear exceeds 1mm, or it is severely burnt, the new part should be replaced when the welding is broken. Slight burns or hair on the contact surface, blackening does not affect the use, can not be treated. If it affects the contact, you can use a small hoe to smooth the light.

4) Pay attention to the contact opening distance and over-travel after repairing or replacing the contacts. Contact overtravel affects the final pressure of the contact.

5) Check whether the auxiliary contact action is flexible, whether the static contact is loose or falling off, the contact opening distance and stroke should meet the requirements, the contact resistance can be measured with a multimeter, and when the contact is bad and difficult to repair, it is necessary to replace the new contact. .

3, arc extinguishing cover overhaul

1) Remove the arc extinguishing cover and use a brush to remove the falling objects or metal particles inside the cover. If the arc-extinguishing cover is found to be cracked, it should be replaced in time.

2) For the grid arc extinguishing cover, attention should be paid to whether the grid is intact or burnt, deformed, severely loose, positional change, etc., if it is difficult to repair, it should be replaced.

4, the maintenance of the electromagnetic coil

1) The attracting coil of the AC contactor should work reliably when the power supply voltage is 85%-105% of the rated voltage of the coil.

2) Check whether the electromagnetic coil is overheated. The overheating of the coil is reflected in the aging and discoloration of the outer surface. The overheating of the coil is generally caused by the short circuit between the turns. At this time, the resistance value can be measured and compared with the similar coil. If it cannot be repaired, it should be replaced.

3) Whether the lead wire and the wiper are not welded or will be disconnected.

4) The coil bobbin has cracks, wear or improper fixing. If found, it should be fixed or replaced as soon as possible.

5, iron core maintenance

1) Wipe the end face with cotton yarn and gasoline to remove oil or dust;

2) Check whether the buffers are complete and the position is correct;

3) Whether the rivet is broken or not, causing the end face of the core to be loose;

4) Whether the short-circuit ring is detached or broken, especially pay attention to cracking. If there is a break or serious noise, replace the short-circuit ring or iron core;

5) Check if the electromagnet is in good contact and there is no misalignment.