Sometimes you get lucky and find the right part on the junk shelf to fix a problem in the field. We have all been there, and then in our excitement we run out to the field with the part, install it and then remember why it was sitting on the junk shelf. Hmmm this contactor rattles when I shake it. It also doesn’t pull in. Today I’ll show you one way to field fix a contactor if you have this problem.
- Remove all power and realize opening a contactor will void the warranty.
- This contactor is a new AF series from ABB. A typical contactor will have a coil on it that would most likely need to be replaced in a but without opening up the box.
- You will need a solder iron, solder and possibly some small cutters. Two flathead screw drivers help with the disassembly as well.
As you can see there is a surface mount (SM) inductor at the incoming power for the “coil control power.” This is hanging by the arrow by some of the inductor wire. Where the pin is pointing is where the SM inductor should be. The solder had held and the body of the inductor fell off.
Next step is to remove the broken inductor (red X) and in a pinch you can bridge this to get the contactor working again (blue short). On a multipin package just check where the traces came into the package and left. You can just short those two together. Keep in mind you will lose some protection against incoming spikes on this control line. But your contactor will work again and you will be back up and running.