Do I even need this motor control equipment

[jamurr65]

Hello all, I disassembled this GE 3hp Triclad motor cleaned everything, replaced the capacitors and bearings. Got to thinking setting it back up on the compressor (well my son did) man that motor is heavy. Is this motor control equipment even necessary with a capacitor start motor? I get a humming noise from it every once an a while when it starts and I have to shut it off and restart it again.
Any advice would be appreciated,

 

[Firebrick43]

Most pumptrol pressure switches are current limited, many at 1.5 to 2 hp on single phase, hence the need for them to actuate a magnetic starter instead of passing the motor current through to the pumptrol directly. If it hums and doesn't start, you likely have a problem with the motor or control. Possibly one of the capacitors is bad(new doen't mean its good) or one of the contacts on the magnetic starter is pitted/burnt and not making correct contact every time.

The unloader could be malfunctioning as well

 

[American Locomotive]

If the humming is coming from the motor starter (and the motor otherwise starts normally), it's probably just the contactor is old/worn. They can sometimes hum when they get old.

 

[LXCam]

Fire summed up everything that could be an issue nicely. I’d look at the contacts in the starter first. If they’re burned and pitted either dress them or replace.

 

[Bert_]

The box is a motor starter. It has nothing to do with it being a capacitor start motor or not.

The starter provides overload protection as well as a much heavier set of contacts than is in the pressure switch.

The humming is nothing to worry about. Lots of starters do it if they get a little rust in the iron core. Some even do it when brand new.

 

[Steve_P]

I would inspect the contacts. I'm sure they will at least need to be dressed, if not replaced, unless someone did it recently.

On my home air conditioner, once it was ~15 years old, I was going thru a capacitor on the compressor about every two years. And the ends of the wiring showed evidence of high current- insulation looked like hell near the connectors at the capacitor. So I was clipping the ends of the wires and replacing connectors every few years- and running out of wire. I talked to the HVAC guy and he said it was normal as the compressor ages, etc. At some point I noticed the contacts looked like ****, they were rusty, so I removed them, blasted them, and copper plated them. That ended my issues and I haven't replaced a capacitor since. Or maybe one 10 years. And I haven't changed a connector since.

 

[jamurr65]

Thanks to all, that explains it all quit well. I got to looking at the starter and wondered how the heck I even figured out how to hook it all up.
Must have done an awful lot of research. probably most came from this forum.
Thanks again