Ingersoll Rand 5 HP motor hums but won’t start

by james
(michigan)

ingersoll rand 60 gal 5 hp 220 single phase runs but after a fill cycle the motor hums but won’t start for 30 mins or so.

I recently had a heavy jack run across the extension cord I made to go to the garage and it tripped the circuit breaker in the house. so I went out and bought new 10-2 solid copper wire the same as I had before only this time I bought the stuff with the bendable metal covering.

I also changed the plug end to the bigger 3 prong as I just got a welder for Christmas so since I had to change the wire because of the miss-hap with the wire being ripped apart so I change the receptacle to the 3 prong that would accommodate my welder as well.

now the compressor will run thru a cycle to fill the tank with no problem but when the next cycle gets ready to start the motor will hum and then the safety switch kicks,

now me being some what a diy I checked all the wires and im getting 110 at each prong from the house and 220 touching both wires on my multimeter, so I did some looking inside the motor and realized it had no ground wire from the motor to the pressure switch so I did that thinking that would help but its still doing same thing.

I use the compressor to work on cars so using the air ratchet uses more air and the compressor goes on and off frequently.

I’m really no pro at this 220 motor but it has worked fine for over 2 years and now its giving me the flux its on a 30 amp circuit breaker but it never gave me this problem before

please help as I’m really unable to go back to wrenching by hand if you need other info please let me know and I will provide also the side of the motor does get hot but not so hot that it will burn you if you touch it.

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Humming IR compressor
by: Bill

James, please see the troubleshooting page on this site about why your compressor won’t start, how to check the compressor motor capacitors, and check those on your compressor.

From what you’ve written I think this is a good first step, and failing caps may be the issue.

Please add a comment here letting us know if the caps were weak or failed will you?

If how to size a motor pulley, we have a guide with a worked example on our site!

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