Baldor single phase motor troubleshooting

[BoostedOne]

Hi there, I have a IR T30 compressor with a single phase Baldor motor and GE starter box.

I bought it from a guy and sometimes(most of the time) it would have trouble getting going from a stop, sometimes tripping the breaker. I thought it might be the start caps, and bought some but didnt get around to installing them. This has been going on for a few weeks, but I have only used it a few times.

Finally it blows the breaker every time.

Anyhow, I put the new caps in, no change.

The motor is an type 3634LC, which is similar to the 1410s. It just doesnt have thermal overloads I dont think..

Pulled the motor off, and I got the specs from Baldor. It says line-line resistance is .494ohms A ph and 1.73 ohm B ph.. Im assuming ph is phase?

If so, what are the phases?

I have big wires labeled 4 and 1, and a small wire labeled E that goes to the stationary switch, and another wire that winds up being wire 5 or 8 that goes to the other side of the stationary switch I think..

I found the resistance very high across the stationary switch, which is what I am assuming to be the problem since I got the resistance down to single digits now by cleaning the contacts, but wanted to check the actual windings and so forth for any other issues before reassembly.

Cant seem to find much info on this online..

Thanks.

 

[Aceman]

Before you tore into the motor, did you at least try it with the pump unhooked?

 

[BoostedOne]

Nope, but the pump turns

 

[930dreamer]

Is the compressor trying to start under load ie pressure on the valves?

 

[bjcouche]

By "Stationary Switch" do you mean the centrifugal clutch switch? Maybe I don't have my terminology correct but there is a start winding and a run winding on some single phase motors. When the motor get's up to speed the start winding shuts off by way of the internal centrifugal switch on the motor shaft. If this switch is open the motor will not start and will stay stalled till the breaker trips. These "motor start windings" are very short duty rated windings and are used to get the motor going. It sounds like you found your problem. Listen when you start the motor, you'll hear a click as it gets to full speed and again when it coasts to a stop. The click is easier to hear on higher inertia devices like drill presses, table saws etc. Note that there are other motor designs with a continuous run second phase winding and capacitor that does not use these clutch switches. They're of course more robust, and expensive so don't find their way to consumer air compressors as often.

Brian