1.5 hp Peerless motor hums on start-up

[Raner]

Hi...
I'm an auto tech but not a electric motor tech...
I joined the forum to see if I could get a bit of help...
I have a 1.5 hp Peerless motor...
It is on a 150 gallon compressor...
I bought the compressor a while back from an old man, He said both the motor and compressor
had be reconditioned...
The other day I was working in the garage the compressor tried to start but the motor just made humming noise...
It just hums on start up. It will run when I help it a bit by hand...
I replace the capacitor does the same thing no change...
I took it to a motor service place and was told the winding insulation looked bad...
I brought is home and took a close look at it and the motor looked like it never been opened...
So I took it apart and the windings look brand new the paint is not even faded...
The switch and contacts look good...
I don't know the correct name for the part right behind the switch on the armature shaft.
But it sure looks like a governor to me. It has two springs and it looks like it
expands with centrifugal force... I checked it and it seems to be working normal...
When I push inward by hand it slides on the shaft very smooth the section where the springs
are connected expands smooth also...
Below are some pictures I took...
Any help with checks I can make with Ohm meter on this problem will be very appreciate ...Thanks...
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[Raner]

Update...
I kept digging around on YouTube and found a video on electric motor repair...
The motor is similar to mine but it is a bit different in some ways...
My motor has a small round looking switch... I think it is an overload switch but not certain...
The motor in the video does not have this component...
Here is the link for the video... If have a bit of time to watch it... Thanks...
Link

 

[John2025]

There're better people than me here, but if it was me I'd undo all those raggedy looking connections and make sure they're clean and tight and make sure the switch has continuity when disconnected. The general idea on this motor is that it starts with 2 windings and then once it gets to speed, the centrifical switch opens and it continues to run on one winding. These motors don't have a lot of starting torque, so the compressor should have an unloader that relieves the air pressure in the pump for starting. That could easily be your problem, if it's pressurized on start-up, the motor will stall.

 

[waross]

The electrical problem with compressor motors not starting is most often a mechanical problem. Take the belt off and see if the motor will start.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[Raner]

Thanks John...
I will replace the raggedy wires...
I removed this motor a while back because I did have a newer GE 2hp I got from a friend...
I know I bought a new capacitor for this motor when the starting problem began...
I did not ever bother to look at it before I posted. I went to look at it right now and
something is not right. The capacitor is messed up, The top cover is loose and the housing is cracked...
The only time this motor has been out of my sight is when I left it at the motor repair place to be checked...
There the only ones that could have installed this old piece of crap...
The capacitor I bought was a new capacitor I installed it and the motor did not run so I just
removed the motor...
I think I will just forget about the motor for now since the one on the compressor is working fine...
The reason is now I will have to get a new capacitor and then fix what ever else is messed up...
Thanks for the comeback John...