rob in nh
Well-known member
I have a IR T30 that starts fine but when the pressure goes down and is ready to start up again it blows the circuit breaker. at the end of the cycle it does unload the cylinder.
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compressor problem
- Thread starter rob in nh
- Start date
Maticuno
Well-known member
Sounds like the capacitors aren't recharging properly after discharging to help the motor start. How old is the compressor?
dfiler2
Well-known member
Sounds to me like you should be looking at your check valve. Does there seem to be an air leak by the pressure switch? That was the case with my Emglo, here is a link on how to test.
http://www.mastertoolrepair.com/air-compressor-parts-check-valves-c-25_4.html
http://www.mastertoolrepair.com/air-compressor-parts-check-valves-c-25_4.html
finn
Well-known member
Unloader / check valve is bad, so the compressor is trying to start against tank pressure.
read this thread,especially my post #15 . compressor works like a charm now. (other than painfully noisy) http://www.garagejournal.com/forum/showthread.php?t=196633
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engineer031
Well-known member
how is the motor bearings ? does it happen when motor is warm ?
dfiler2
Well-known member
Sounds to me like you should be looking at your check valve. Does there seem to be an air leak by the pressure switch? That was the case with my Emglo, here is a link on how to test.
http://www.mastertoolrepair.com/air-compressor-parts-check-valves-c-25_4.html
I still think this is the most likely cause to your problem.
Kellyblues
Well-known member
Ive worked on tons of those with that very problem. 99.98% of the time its the check valve, unloader or start capacitors in that order. We had a ton of these at work in our out building and such and because they would sometimes sit for extended periods of time without being turned on the check valve would get stuck.
dfiler2
Well-known member
Ive worked on tons of those with that very problem. 99.98% of the time its the check valve, unloader or start capacitors in that order. We had a ton of these at work in our out building and such and because they would sometimes sit for extended periods of time without being turned on the check valve would get stuck.
Right, in fact if you go to Master Tool Repair and try to order a pressure switch or capacitors they tell you to test your check valve first. I'll bet they have saved many people like me from getting frustrated trying to solve the problem.
If the unloader valve is working correctly and the check valve doesn't hold, you'd have a constant air bleed from the tank through the check and out the unloader vent. My guess is the unloader isn't functioning. It's usually on the bottom of the switch attached to the check area by a small air line. If the unloader fails to open, the motor is then starting against tank pressure.
dfiler2
Well-known member
dlcwent
Member Emeritus
Is the power line to it the right gauge wire to run it. I ask because I've seen a compressor do the same thing because whoever wired it up, used a wire that was too small to carry the draw it needed to start. I am just throwing out an idea, not saying it's the problem.
i know the supply to the garage is on the small side because the circuit breaker will buzz on start up. the compressor was installed in 88, it had a smaller compressor and if this is the case then i will go back to the smaller size as i don't want to dig up the driveway.
dlcwent
Member Emeritus
Maybe someone on here can tell you how to test that theory.
Maticuno
Well-known member
What gauge wire over what distance from the main to the garage? What gauge wire over what distance from the sub to the compressor? Is the compressor the only thing on that 220 circuit? What amperage breaker? Has it ever been replaced? Does the breaker get warm/hot to the touch when the compressor is running?
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i started the compressor and let it build up and when it shut off it let off some air which i assume is the unloader check valve. i don't hear any air leaking around the valve or pressure switch.
Unloader and check valve are different parts. You describe a normal sound for correct operation.