10 HP Quincy compressor (finally found a fall project)

Whoo-hoo! That looks to be a pretty good find! Want to trade? :)

Just kidding. I need at least a 15 hp motor to stand a chance of getting

3-phase installed at my place.

Btw, the local Quincy service rep has been great for supplying .pdf files of all the manuals for my model.

Todd

:) This one, is about as big as I can handle!!!

And 10 HP is about as much as I can run at home, even with a drive (60 amp subpanel).

I just uploaded a brochure on my website (not a manual).

It does about 35 CFM, if I recall correctly.

i

Todd, thanks for a suggestion to ask them for a manual.

Quincy just emailed me the manual and I uploaded it there and to my downloadable manuals archive.

i

Hmmm ... single stage! In my limited experience, the large compressors have been 2 stage. Now that I think about it, 2 stage gives you higher pressure, but single stage greater cfm (for same horsepower). I think.

Bob

I am not sure, yet, if it is single stage or not. I am going to have a look in a couple of days.

i

Why do you think it is a single stage compressor? It looks like from the literature, all the QT models are 2-stage compressors.

Hey nIggy,

It has two intakes with filters. It is a 2 cylinder single stage. A

2-stage has only a single inlet. The output from that first stage goes to the second stage cylinder, which also will be smaller.

Brian,

It is a four cylinder, two stage. Each bank has a low pressure and a high pressure cylinder. Admittedly I haven ever seen that particular configuration but the documentations shows that. It is in fact a QT-15, not a QT-10 as it says on the tank.

The high pressure cylinder is just barely visible beyond the low pressure, look low, just above the crankcase and you can see the high pressure cylinder.

George

NICE compressor. Quincy's are really top of the line. You need to arrange the VFD to get it up to speed before the unloaders kick out. There may be some way to control the time delay, although this one doesn't look like it has electrical controls for the unloader.

I got a smaller, single-stage Quincy at a scrap yard that had a continuous-run motor and totally pneumatic pressure controls (using the unloaders). I built a microcontroller-based dual-mode controller for it that unloads for spin up, waits for oil pressure to build, then loads the compressor, and keeps the motor on for one minute after no more air is needed. The unloader is controlled with a solenoid air valve. The motor is controlled with a 50 A, 400 V solid state relay. See pix at

box above the motor is the controller. The white thing to the right of the tank is a refrigerated air dryer that I hauled out of the trash at work.

With 2 HP, the sensible thing was to go with a single-phase motor. You'd need to derate the VFD for the compressor application, but it ought to work. The slow start of the 10 Hp motor/flywheel should be much nicer to the neighborhood, too.

Jon

Yes, that's right, that was why I suspected that it was 2 stage.

Thanks. I will see.

i

Surprisingly, in agreement with what you just said about QT-15, the Quincy service rep emailed me the manual for QT-15. I thought that he simply made a mistake. But he told me, once I said there is two cylinders on each side of the V, that "I know exactly what pump you have". And he sent me the QT-15 manual. Now I see this in a different lightl. It looks like a QT-15 with a 10 HP motor.

i

Todd Rich wrote: > Why do you think it is a single stage compressor? It looks like from the

From the pictures. It looks like 2 cylinders, each with an air intake. The 2nd stage cylinders are behind & not easily visible. Bob

Which would be an excellent setup for longevity if the pulleys are set up right. Running a larger pump slower increases its lifespan, not that Quincy's wear out particularly fast in the first place.

There should, though, be an unloader valve somewhere, right?

There are some little copper lines on the top of the head?

That's awesome.

Very cute.

I have a dryer, too. (also got it from trash, but had to pay $10) I use dry air for almost everything, these days.

I am thinking about maybe 0.5 sec acceleration. 1 second at most.

i

Yes, being in the middle between min and max RPM, indeed is great for a lot of reasons.

i

Hey George,

Sorry, but I didn't look that close. I stand corrected.

And Wow!! That sucker will produce some air!!

Take care.

Brian.

I think the unloaders are those brass pieces sticking out of the cylinder heads. (Those look different than mine.) What controls the unloader can vary. On compressors with motor controls, they often use a valve that is operated by oil pressure. When the oil pressure is developed, the valve shuts off air and the unloaders allow the compressor intake valves to work.

Yes, mine are operated by a diaphragm about 1.5" diameter. Maybe due to the higher pressure of the 2-stage, the unloaders are smaller. Yes, some copper lines apply air to the unloaders to lock the intake valves open.

Jon

Yes indeedy, only thing I have seen that will produce more air is a Southern Democrat, passionately defending his beliefs.

George