Air Compressor Help

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Sep 2, 2010
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Happy New Year All..!! I picked this Campbell Hausfeld 60 gal stationary air compressor from a job site a while back ago for free. They used it to run a die cutter table and it stopped working. Where should I start for diagnosing? Looking at the switch box, the white wire looks burned and melted. I do not have 240v in the garage. I'm going to run a temp extension from my electrical panel so I can test it out. Someone said start and/or run capacitors is the first place to look? Btw, I can freely spin the belt drive so nothing seems seized up. If you have any suggestions on how to test/diagnose this compressor, I would appreciate it :thumbup: [Linked Image][/URL] [URL=https://s745.photobucket.com/user/Hiccaburp/media/Garage/IMG_9769_zpsww7crffm.jpg.html][Linked Image] [Linked Image] [Linked Image] [Linked Image][Linked Image]
 
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Take off the belt and see if the compressor will turn by hand. If it does you are diagnosing the motor. You had a connection burn up, so that must be fixed. You can connect 220 directly to the motor, and bypass the switch and see if it runs. I bet it does not. The motor may be grounded so if you do not know how to avoid electrocuting yourself best to leave it alone. Harbor freight sometime has inexpensive motors, be aware that no all motors are rated the same. Good Luck, pay your life insurance Rod
 

HiccaBurp

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Originally Posted by ragtoplvr
Take off the belt and see if the compressor will turn by hand. If it does you are diagnosing the motor. You had a connection burn up, so that must be fixed. You can connect 220 directly to the motor, and bypass the switch and see if it runs. I bet it does not. The motor may be grounded so if you do not know how to avoid electrocuting yourself best to leave it alone. Harbor freight sometime has inexpensive motors, be aware that no all motors are rated the same. Good Luck, pay your life insurance Rod
Thanks Rod. The motor and compressor spin freely. If the motor does not run, could it be something as simple as a start or run capacitor? This one has both. As for life insurance, I refuse to get it as to not give the wife more incentive to get rid of me laugh Alex
 
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Small motor shop might be your best bet. If the compressor also turns freely, I would suspect either a failed capacitor or perhaps the centrifugal start switch has a problem. You would have to take the end shell off to get to that. Might also check to make sure the unloader valve isn't stuck; it relieves pressure from the pump to the check valve so the motor can start. Make sure the tank check valve isn't stuck open. If the unloader valve or check valve stuck and the motor was trying to start against the tank pressure it may have pulled too much current and overheated the wire. Odd, since there's a circuit breaker on the back of the motor that's supposed to prevent that.
 
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Wire past the pressure switch, directly to the motor leads to test the motor. Wire to a breaker rated to at least 20 amps for inrush and conductor protection. If the motor starts and runs get a new pressure switch. If it initially starts to turn but stops or stays slow a run cap. If it refuses to run initially a start cap. Do this unloaded. Make sure any bad wiring has been removed.
 
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HiccaBurp

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Originally Posted by Dave Sherman
Small motor shop might be your best bet. If the compressor also turns freely, I would suspect either a failed capacitor or perhaps the centrifugal start switch has a problem. You would have to take the end shell off to get to that. Might also check to make sure the unloader valve isn't stuck; it relieves pressure from the pump to the check valve so the motor can start. Make sure the tank check valve isn't stuck open. If the unloader valve or check valve stuck and the motor was trying to start against the tank pressure it may have pulled too much current and overheated the wire. Odd, since there's a circuit breaker on the back of the motor that's supposed to prevent that.
Thanks for info
Originally Posted by sloinker
Wire past the pressure switch, directly to the motor leads to test the motor. Wire to a breaker rated to at least 20 amps for inrush and conductor protection. If the motor starts and runs get a new pressure switch. If it initially starts to turn but stops or stays slow a run cap. If it refuses to run initially a start cap. Do this unloaded. Make sure any bad wiring has been removed.
I will wire past the pressure switch to test the motor. Thank you for the information, very helpful..!!
 
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VOM on the in and out lines will tell you if the switch is gone, it has not pressure in the tank so it should have continuity. I don't get how they can call that 6HP (4.4Kw) when the motor label clearly has less than 3Kw on the tag. That will run okay on a 3 HP motor if it needs one.
 
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Originally Posted by Trav
I don't get how they can call that 6HP (4.4Kw) when the motor label clearly has less than 3Kw on the tag.
Craftsman, CH, and possibly other compressor manufacturers got called out for that a while back. The HP ratings were cryptically based on how much power they could deliver for a split second from the inertia of the motor and pump if it were to suddenly stop. Pretty meaningless for a compressor. My Craftsman compressor had a safety recall that involved replacing the motor shroud. Before it left, it had prominent "3 HP" decal on it, even though it runs on a 120 VAC 15 amp circuit. The new shroud said "1.5 HP" when I got it back.
 
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I had a similar issue with my air compressor. The screws in the pressure switch loosened a little and arced and burned. Lots of vibration in an air compressor. My solution was to wire nut the two wires together and have the pressure switch only switch one leg of 220V. Probably not good if others use the compressor and/or its left powered all the time. I only have the circuit breaker ON when I want to use the compressor. My pressure switch was for a 2 stage compressor so a higher PSI. I found a rebuild kit with new contacts and screws on Ebay as my pressure switch exact replacement was expensive. Your compressor being a single stage may have a cheaper pressure switch. Or it could be something froze up and the motor began to draw a huge current and burned the pressure switch.
 

HiccaBurp

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Originally Posted by Donald
I had a similar issue with my air compressor. The screws in the pressure switch loosened a little and arced and burned. Lots of vibration in an air compressor. My solution was to wire nut the two wires together and have the pressure switch only switch one leg of 220V. Probably not good if others use the compressor and/or its left powered all the time. I only have the circuit breaker ON when I want to use the compressor. My pressure switch was for a 2 stage compressor so a higher PSI. I found a rebuild kit with new contacts and screws on Ebay as my pressure switch exact replacement was expensive. Your compressor being a single stage may have a cheaper pressure switch. Or it could be something froze up and the motor began to draw a huge current and burned the pressure switch.
I just found this while taking apart the electrical so I can test the motor. The bottom black motor line was barely touching the connector. Wonder if it came loose which overloaded the other line hence the burning/melting. What are the chances that if I fix this connection it will work without issue?? Hmmm [Linked Image]
Originally Posted by Dave Sherman
Originally Posted by Trav
I don't get how they can call that 6HP (4.4Kw) when the motor label clearly has less than 3Kw on the tag.
Craftsman, CH, and possibly other compressor manufacturers got called out for that a while back. The HP ratings were cryptically based on how much power they could deliver for a split second from the inertia of the motor and pump if it were to suddenly stop. Pretty meaningless for a compressor. My Craftsman compressor had a safety recall that involved replacing the motor shroud. Before it left, it had prominent "3 HP" decal on it, even though it runs on a 120 VAC 15 amp circuit. The new shroud said "1.5 HP" when I got it back.
I looked at the motor to see if it looks like it's been replaced.. but it has not. Probably false/misleading advertising frown
 
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I don't think the label cause it not to start? Fix those connections/connectors first and it will probably be good to go. There is also a bleeder valve that can cause issue if it is not bleeding the excess pressure or may be that is the pressure valve.
 
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Replace the wiring and go for it. Worst that can happen is the magic smoke gets let out again.
 
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Unplug and use a VOM to check the pressure switch contacts are probably bad. Any kind of burned or melted wires indicates a bad or less than good connection where heat will be created. That bad connection will heat up and heat will migrate down the wires in a slow self destructive process. replace the pressure switch and power wires beyond where they looked heated as there can be heat damage inside the insulation. I doubt the motor is bad if it was run within load spec and did not overheat.
 
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Get a meter. Find out where you lose voltage. If you have full voltage to the motor then the motor or capacitors are bad. From the looks of the pictures the pressure switch is toast. Resistance causes heat which causes corrosion which causes resistance.....
 

HiccaBurp

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Originally Posted by Kawiguy454
Unplug and use a VOM to check the pressure switch contacts are probably bad. Any kind of burned or melted wires indicates a bad or less than good connection where heat will be created. That bad connection will heat up and heat will migrate down the wires in a slow self destructive process. replace the pressure switch and power wires beyond where they looked heated as there can be heat damage inside the insulation. I doubt the motor is bad if it was run within load spec and did not overheat.
I'm going to bypass the switch to make sure the motor is working.. if so, then new pressure switch. If the motor is not working, hopefully it's as simple as a capacitor. I'm about to run a cable from my fuse box to test it. Question, I have a 2 pole 20amp for one of my AC's. If i take those 2 wire out, wire the extension to it and the green to the ground bus, that should work?
Originally Posted by Donald
Get a couple of feet of #12 wire and run new wire from the motor to the pressure switch.
Working on getting power out there now to test.. will check motor wire continuity for sure
Originally Posted by Ozonkiller
Get a meter. Find out where you lose voltage. If you have full voltage to the motor then the motor or capacitors are bad. From the looks of the pictures the pressure switch is toast. Resistance causes heat which causes corrosion which causes resistance.....
I have a meter, will start diagnosing now.. but the pressure switch does look toast
 

HiccaBurp

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I got the air compressor running! I bypassed the switch and it kicked right over and started building pressure. Here is a quick video I made. The whistling you may hear is the plug i had in the air outlet wasn't completely tight, i have since tightened it and no whistling. https://youtu.be/bReDpnykI5E
 
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