Quincy compressor question

[Paintguy007]

I recently picked up a Quincy 230.

Hooked it up, and it runs constantly. It appears the pressure switch isn't working. It will build to 140psi and just keep going. It's running a 220v single phase 3hp baldor motor. Any suggestions

 

[sld961]

Is the pressure switch adjustable? Can you turn down the cut out pressure?

If so, with it at max pressure, and with it unplugged, turn down the cut out pressure until the switch opens.

Also, look at the contacts and make sure they're not welded together from bad contact.

 

[G_P]

I hope you have a working relief valve on that unit!
As SLD said, check the pressure switch. Someone may have swapped on one from a 2 stage and its set to cut off at 175psi or so. Most of them will have a diagram on the inside of the cover showing how to adjust cut in and cut off pressures.

 

[Paintguy007]

Thanks guys. I will look into further tonight.

 

[md21722]

Two stage cycling is commonly 145 on 175 off. If it goes past 175 shut it off and investigate the pressure switch. Adjust or replace as needed.

 

[Woodworker99]

I used to own a Quincy 5120 compressor and it had dual control - I can run it as start / stop or as continuous run ( it would pump up to a set psi and then a valve opens compression stops but the pump still runs and as the psi drops to a set psi the valve closes and compression resumes ). Maybe your unit is the same. Does the pump have a brass valve that you loosen by turning the knurled nut if you want start/stop control or by tightening the knurled nut if you want continuous run control ? The brass valve is located near the oil pump/oil filter.

 

[MacMcMacmac]

This is a single stage compressor and is built to run around 100psi or so. Don't set it up for much more than that as it runs out of breath pretty quickly.

 

[redmondjp]

This is a single stage compressor and is built to run around 100psi or so. Don't set it up for much more than that as it runs out of breath pretty quickly.

Yes, I would set it at about 115-120psi maximum.

 

[truckdriver]

It's possible that it has dual controls. We need a picture.

 

[Paintguy007]

Update: it works. Took the pressure switch apart and cleaned it, readjusted it. Works as it should. Now the only issue is that I can hear it leaking air back through the intake. Guess that's what happens when you don't really get a chance to completely check them out before buying.

 

[redmondjp]

Update: it works. Took the pressure switch apart and cleaned it, readjusted it. Works as it should. Now the only issue is that I can hear it leaking air back through the intake. Guess that's what happens when you don't really get a chance to completely check them out before buying.

No worries, it's probably just some rust on the output valve seat - they tend to rust when not used regularly (one of the downsides of disc valves as opposed to stainless reed valves). You can add a check valve to the output line so this doesn't happen, and/or service the valve.

 

[Paintguy007]

No worries, it's probably just some rust on the output valve seat - they tend to rust when not used regularly (one of the downsides of disc valves as opposed to stainless reed valves). You can add a check valve to the output line so this doesn't happen, and/or service the valve.

Thanks, I know it sat unused for a while, but it's very clean

I like it because it's so quiet in my garage, you barely hear it run.