fasco contactor

[dmangalo]

I installed three contactors for a fire surpression system, two of the three coils controlled by a switch which is fed from micro switch(normally closed) inside system. These two coils energized close contactor normally open and feed an air handler, and the second a hood which both must run simultaneously under normal conditions. The third contactor coil is controlled from the normally open of the micro switch in the system which is now in "EMERGENCY" mode and has de-energized the the air handler and is now energizing only the hood per fire marshall.

The problem is these fasco contactors keep vibrating and make alot of noise, the parts house guy told me to hit the contactor to get the armature back in line again (after replacing the two which run simultaneously) and quiet them down.....but just am not in mind set that a "BFH" is the answer.

Has anyone else had trouble with fasco? Think I am gonna go to grainger (instead of ma and pa's parts) and get different brand like alan bradley or square d. Cause I cant keep going every week to replace fasco.

Thanks,
Dman

[Wgoodrich]

There can be several different problems that can cause this. Some are going to fail if present some are just harmonic vibration, some are misfits.

Check that the armature has been installed inside each coil. I have found at times that an E/C leaves the armature of a contactor coil sitting on a ledge instead of replacing it when replacing a coil.

Check the voltage rating of the coil. Sometimes there is a mismatch of voltage rating and voltage served. Example is a 240 volt single phase coil on a 208 volt three phase system. Some are foreign expecting 50 cycles instead of 60 cycles in our area. Check the cycle rating of that coil to ensure you have a match.

Some are just not mounted tight to the structural box it is mounted to. Check that all screws including non used electrical contact screws are tight and the mount is tight that can cause this buzzing or vibration.

Just some ideas

Wg