contactor chatter

[powerplay]

i ran across an old GE 200 line motor controller that controls a well pump through pressure switches that has some rust where the armature contacts. I cleaned it with an wire brush hoping the chatter would stop, but no luck. Is it better to replace the compete contactor or did I not clean it enough? There is adequate voltage, and the chattering may have been going on a long time...could that have burnt out the coil that will continue to cause it to chatter? I was wondering if I should just replace the whole contactor or replace the 240 volt coil. Is there an easy troubleshooting chart for motors and contactors someone could refer to me please? Thanks again!

 

[ptonsparky]

Is the noise just a very load hum? Make sure you cleaned all the mating surfaces. Sometimes a little WD-40 or other similar product helps to loosen the rust. The coils do draw more if the armature is not fully closed so I suppose that could lead to failure. Also could be time to just replace the whole thing. Probably old enough.

 

[kingpb]

If the voltage is good at the coil, and the connections are good and you cleaned everything, you could try replacing the coil.

I assume the contactor is mounted upright vertically, if not that could be an issue.

 

[billsnuff]

depending on how old you might check for a loose shader ring/coil.

 

[Jraef]

GE 200 line contactors were notoriously noisy. There are spring clips that hold the coil in and also are how the voltage gets to the coil. This made it really easy to change coils, but unfortunately metal fatigue in the springs allows a lot of chatter after a while. I hate them for that reason. I would replace the springs if possible but if not, put in a new starter and be done with it...

 

[powerplay]

thank you for the excellent feedback! I guess no sense in wasting time, it has been chattering for awhile now and that would have damaged the coil...and so forth? I am planning to change it to an Moeller motor controller, as it's the same cost as an replacement contactor alone.

 

[templdl]

Check the control circuit itself.
If you have a simple 2 wire control that is the contactor is controlled by a level switch of some sort you probably have a bad contact at the switch itself that often causes an intermittent control voltage to the contactor coil resulting in chatter.
You can burn of a set of coil contacts in no time at all.
As an application engineer a customer called me regarding a potential warranty problem for a starter of mine, welded contacts.
I asked him to check his control circuit where he found a corroder contact on a pressure switch which was caused by a small refrigerant leak in his chiller.
Problem solved.

 

[knoppdude]

Check the control circuit itself.
If you have a simple 2 wire control that is the contactor is controlled by a level switch of some sort you probably have a bad contact at the switch itself that often causes an intermittent control voltage to the contactor coil resulting in chatter.
You can burn of a set of coil contacts in no time at all.
As an application engineer a customer called me regarding a potential warranty problem for a starter of mine, welded contacts.
I asked him to check his control circuit where he found a corroder contact on a pressure switch which was caused by a small refrigerant leak in his chiller.
Problem solved.

This is an excellent troubleshooting tip to add to my bag of tricks, and something I will start looking at more when problems with starters arrise. I think all of the advice given is good, but this tidbit is a gem.

 

[templdl]

Thank you knoppdude.
I have learned so much as an application engineer when I've stepped back and taken a look at the actual application itself.
I have always backed up my product 100% if it failed because it was found to be defective. But I have to realize that I represent quality product that are reliable. I have even been known to even replace a product that is out of warranty if it is evident that there was a factor defect that caused the failure.
As such I have found that misapplication has often caused my product to look bad and that offering a warranty replacement into a bad application will only lead to another product failure. Then, the electrician, maintenance person or whomever will conclude that my product is a piece of garbage when it actually is something else that is causing the failure.
On one size 5 starter application the user was jogging it a lot because of necessity and was tearing up contacts. The solution was to replace it with a vacuum contactor. Problem solved.

 

[ptonsparky]

I hate to think what jogging a size 5 starter was doing to the motor.

 

[templdl]

I was used for the up and down motion of the ladle for a continuous caster in a large steel mill in east Chicago. Though I had no knowledge of the motor application itself I would have to understand that the company who engineered the process had taken the jogging duty requirement into its design consideration.
The problem was that it was never included as a specification for my control.

Another thing that appeared to be an issue with vacuum contactors in some application is that on vacuum bottle appeared to get more contact wear that the other two which showed up with frequent opening and closing of the contactor. Although we never were able to verify this be understanding that these contactors opened extremely quickly the problem appeared to have been caused by the contactor opening on the same cycle where the contact on a specific phase broke the current on a higher level of the sign wave which resulted in more contact wear on that phase. We surmised that it may have resulted from the single phase control voltage dropping the contactor out consistently on that cycle which wore out one bottle much faster that the other two. That was our theory anyway.

This was back in the mid 90's so vacuum contactors bottles were relatively a new technology.