Quincy QT54 problem

[soloc4]

I have had my Quincy compressor for about 2 years and I cannot seem to find a solution to my problem. The thermal switch trips after about 5 or 6 cycles while running high volume tools, i.e angle grinders, sanders, and especially my blast cabinet. It is hard wired to a dedicated 240V, 40A breaker with 10/3 wire about 3 feet in length. The amperage draw is 20A with no load (belt removed) and 28A under load (pump attached). After 5 cycles the amperage goes over 30 amps, tripping the thermal switch. The amperage rating on the motor plate is 20A. The motors is recieving the full 240V, so I am at a loss. The Tech line at Quincy couldn't help me either. Do i need to run a larger gage wire? and will this decrease the amperage draw from the motor? Any help would be greatly appreciated.

 

[71goldss]

Here's a fairly recent thread with a problem similar to yours. You may want to send a PM to the OP to see if he found the problem.



http://www.garagejournal.com/forum/showthread.php?t=212927&highlight=Quincy+compressor

 

[theoldwizard1]

If the recommended breaker is 40A, I would say you need bigger wire, at least 8 maybe 6.

Also, switching to a synthetic oil on the pump would help some. Worst case, add an external fan blowing on the motor and pump, even if it is 3 or 4 small 240V fans.

 

[soloc4]

I read that post and it has a lot of good information, but my compressor is not in enclosed and is not seeing the ambient heat that his does (I live in the Pacific Northwest, typically about 65 - 70 degrees) although our experiences are very similar which makes me think his are not all heat related. I am also running Amsoil compressor oil in the pump.

 

[71goldss]

If the recommended breaker is 40A, I would say you need bigger wire, at least 8 maybe 6.

Also, switching to a synthetic oil on the pump would help some. Worst case, add an external fan blowing on the motor and pump, even if it is 3 or 4 small 240V fans.

I've been running off a 30A breaker (recommended) with 10 gauge wire for two years since buying the same compressor new. I've run for hours at a time sanding my car with a DA in 100 degree weather and have yet to trip the thermal overload. I do have quite a bit of air flowing over it when in use though.

 

[soloc4]

I started with a 30A breaker, switching to 40A did nothing. I'm not an electrical engineer, so I don't know if increasing wire gage would decrease amperage draw on an electric motor. The motor drawing it's rated 20A with no load is my concern. I did turn the pressure switch down to 150 psi. I'll see if that helps.

 

[theoldwizard1]

I started with a 30A breaker, switching to 40A did nothing. I'm not an electrical engineer, so I don't know if increasing wire gage would decrease amperage draw on an electric motor. The motor drawing it's rated 20A with no load is my concern. I did turn the pressure switch down to 150 psi. I'll see if that helps.

Go back to a 30A breaker. Possible bad thermal overload switch. External fan is the simplest solution.

 

[Fixnair]

I think I would check the interstage pressure if it is a two stage pump. In a two stage compressor the 1st stage should no see pressures over 40 psi when the discharge pressure is around 125 psi.

 

[allanjs]

I started with a 30A breaker, switching to 40A did nothing. I'm not an electrical engineer, so I don't know if increasing wire gage would decrease amperage draw on an electric motor. The motor drawing it's rated 20A with no load is my concern. I did turn the pressure switch down to 150 psi. I'll see if that helps.

The motor should not draw 20amps with no load. Go back to the 30amp breaker. 40 is too large for 10ga. The overload circuit is doing its job properly. Sounds to me like the motor has a bad winding. Contact the motor manufacture and explain your problem. If it's a warranty issue they will probably direct you back to Quincy. Or you may get lucky and they will take care of it for you. Another option is take the motor to a local motor winding house and have them check it and give you some options.

 

[sparky7]

i run 8 gauge wire with a magnetic starter and a 40 amp breaker, same compressor

 

[shannonw]

Check your run capacitor, guarantee it's probably bad with that amp draw. I had the same motor and checked the amps quite a bit with my meter.

That said if it's the same motor as in the other thread it's an SPL. I picked up the same model motor for my ingersoll rand ss5which had gone through it's original emerson, that baldor (it was a quincy part number, was new and I had a motor shop even check it out) I thought surely this would work since it's on a quincy, had the same FLA.

IMHO i think that motor because of the SPL is actually a 3horse motor, who knows with the SPL stuff. I could never keep it from tripping the thermal on extended run times even after replacing capacitors.

16 amp it'll run all day without tripping, the 21 rating I think means for brief periods as it's over the 100% of the motor...too much running (at the higher pressures the pump pulls more amps..probably around 90+psi or so) and it overheats. Brief periods this is ok, but extended runtimes it will eventually trip.

I ended up reselling the compressor sans motor and picked up an old IR with an older baldor with an actual 5hp rating on the nameplate.

Google SPL and you'll get quite a lot of info.

 

[shannonw]

If you're drawing 20 amps no load. run capacitor, mine blew it too and that sounds about right. of course could be other things, but assuming both legs of the 220 is good, probably capacitor. There's a start and a run.