3 bay D&S ss equipment,

[cleaning up mud]

1 bay 5hp motor the motor contactor is sticking and tripping the overload protector, heavy burnet smell in contactor. New motor, new contactor, new overload protector, new circuit breaker, new wiring to motor. Commercial electrician cannot find any problem. Has anyone every had this problem before and what was it? I replace the soap and wax coil with are the only two high pressure chemicals, also the transformer was switched between bays, also we installed a new bay selector switch, still the same problem it works for a while then the contactor sticks and overload trips, not before damaging the contactor. Any ideas? thanks.

 

[MEP001]

I'd like to help you but I don't get out that way anymore since Chris stole all the chemical sales west of us.

So after all the new parts it ran fine for a while and burned up the contactor again?

 

[cleaning up mud]

come fix it. you have my number it hasnt changed in 23 years.

 

[Keno]

Which part of the contactor is getting damaged? The coil or the contacts? Also, why is the contactor getting damaged before the overload trips? Is the contactor undersized for amps running through it or the overload oversized for the motor amps?

 

[cleaning up mud]

Not sure, the contactor and overload are all the correct size, electrician has been here twice and find nothing wrong with motor or voltage.

 

[Keno]

So is it a control side issue? My thinking is that a contactor should be able to run a motor basically indefinitely without getting damaged if it is properly sized and the motor isn't over-amping. Loose or corroded connections?

 

[cleaning up mud]

we swapped transformers with another bay, nothing changed, next i guess we will run new cable from the ss equipment to the bay meter. no problem with any other bays.

 

[Keno]

Might be worth re-stripping and re-terminating your connections before running new wire.

 

[MEP001]

It's probably not an issue on the low voltage side. If the transformer was bad or the wiring was the issue, it just wouldn't run. If the contactor is fusing shut, your electrician is doing something wrong and burned up your parts. The only thing I can think of could possibly be the pump, but I seriously doubt the pump would intermittently seize and unjam, and I know you aren't getting the belt so tight that the motor won't turn, and even then the overload or breaker should trip before the contactor melts.

 

[Randy]

How long does it take for the motor contactor to stick and the motor overload go bad? Have you checked the voltage going to the motor contactor, both 24 volt and 220 volt when the bay is running? Have you put a clamp on Amp meter on the leads going to the motor? What is the Amp rating on your motor contactor? I use a 35 Amp motor contactor with no overload.
I have a intermittent problem with the 5 Amp 24 volt circuit breaker tripping in one bay that's driving me nuts. Electrical problems can be a bitch to fix sometimes.