Quincy QR possible fixes please!

[nivek]

I recently purchased a used Quincy ff350 air compressor which is basically two 350 (roc 105) pumps on one tank.
I just got it to my shop and wanted to test it to make sure it was all working before going forward to the install. The compressor is 3 phase 10hp and I rigged it up to my phase converter (I only have single phase entry) directly to the motor. It got the pump turning but no oil pressure on the gauge.
The pressure in the tank got to 75lbs before I turned off the power. The oil pressure gauge never moved.
I then rigged it so the second 350 pump worked, not at the same time as the first because I do not have enough electricity to have the 2 pumps running at the same time. The oil gauge on this one never moved either.
I am brand new to this compressor so is there something I am doing wrong, something special to look at? The chances of both of them not working is slim I would think.
I thought this model would not build air pressure if there was not any oil pressure present.
Does it have something to do with the control box in picture (Johnson controls). There is a tubing coming from the oil gauge to this box but I am not sure what is does. Thought it might be to cut the electricity if there is no oil pressure? Wouldn"t work now because I bypassed it but does it stop my oil pressure gauge from working? For sure it has something to do with the oil pressure.
How do I check to make sure the pump is getting oiled? Can the unloader be stuck closed?
I"m going to run only one pump and have a spare for the future. I will be replacing the 10hp 3 phase motor with a single phase motor. I will have more questions on this in the future because the control panel is more complex than I anticipated!

Thanks in advance for any responses.

 

[Anonymous-0]

Compressor drive motor turning the right way? The driven pulley blades should push the air across the compressor head. Are both gages working or could the pipe they are connected with plugged?

 

[KSTractor]

Are you sure the motor is turning it the right way it will pump air in either rotation but only pump oil in the correct one. There is an adjustment for oil pressure on the oil pump but I don't remember where. Also the screen gets plugged up if there is a lot of moisture in the oil.

 

[evilboweviel]

rotation has to be correct to build oil pressure

 

[Anonymous-0]

Forgot to mention that I checked the rotation with the arrow on the flywheel. seems to be good.
Apparently the compressor was just taken out of service and is fully operational.
Can anyone tell me what that control box does that is connected to the oil line?

Thanks for the quick replies

 

[DH in Carolina]

First thing is your pressure gauge good? That is a Johnson Controls P28 oil pressure cut out differential control. It will shutdown your compressor if no rise in oil pressure is seem in 30-60 seconds. Plenty of information on the web about it. the oil pump is facing you in the first picture. My Qunicy compressure runs about 15 lbs after it is warmed up. DH

 

[nivek]

Thanks for the info on the P28. Googled it and found some good stuff, most of all, it does not require 3 phase power for it to function. I will be able to use it with my final setup.Sounds like a handy device to have.
I am not sure if the gauge works but I tried both pump heads and both give me a zero reading on the oil gauge leading me to believe I am not doing something correct. Do you think the P28 has something to do with it?
Why did the pump produce 75psi with the gauge reading zero. I thought the unloader would prevent this in the case of no oil?
The P28 is not funtioning now because I bypassed it by connecting power directly to the motor so I could witness the pump turning.

 

[XRogerX]

The rotation of the flywheel has to match the direction of the arrow on the oil pump, where it says "TOP" just above the filter. If you have to reverse it, you must take off the oil pump assembly, and rotate it 180 degrees until the other "TOP" is at the top and the arrow is pointing in the opposite direction. Relocate the pressure gauge and blanking plugs on the outer case, and swap the internal Allen pipe plugs under of the oil filter.

Now if rotation is correct and you still have no oil pressure, there are a couple of things you can check. You can loosen the locknut on the oil pressure regulator and try screwing it in to set it to a higher pressure to see if it hasn"t taken a set over the years and is bypassing oil to sump. You can also quickly check to see if the o- ring on the stub shaft that goes into the end of the crank has hardened up and isn"t sealing. The oil pump is driven off the end of the crank by a roll pin which passes through the end of the crank. The shaft from the pump has a notch that slips over the pin for drive. The outside of this shaft is sealed by an o-ring that slips inside the end of the crank. If it is leaking, oil will spray out the end of the crank instead of going through it. Thirdly, there are 1/8" NPT plugs in the crank itself which seal up the drilled passages. If one is missing, no oil pressure will build. One last thing to check is the oil pressure bleed valve which is in one of the throws on the back of the crank. If you look closely through the side inspection door, you can see a large hex fitting on the bottom of one of the crank counterweights. This is a special centrifugally operated valve that seals when the compressor is running to keep oil pressure up inside the crank. When the crank stops spinning, it unseats and bleeds of oil pressure so that the compressor will unload through the hydraulic unloader on the side of the crankcase. If this valve is stuck or the seal is worn, it will bleed oil pressure.

 

[DH in Carolina]

The P28 control is a safety shutdown and has nothing to do with building oil pressure. This compressor was probably used for climate control air pressure in a large building and may not build air pressure much above 100 lbs. Go to the Quincy website and get a manual emailed to you. Roger X knows a lot more about Quincy compressors than I do. I know Johnson controls and climate control. You will also have a lead/lag control on these compressors allowing one to operate and next time the other one runs.

 

[nivek]

Will the oil pressure gauge still have a reading even if I have the Johnson oil pressure cutout attached to where the gauge is?

 

[XRogerX]

You are also correct that the pump should not build pressure if there is no oil pressure, so either the unloader is faulty, most likely due to perished seals, or you do have oil pressure and your gauges are shot.

It seems like that's a lot of compressor for what you need. If you got it cheap, do you think it would be worth turning it into cash, buying a smaller unit and pocketing the difference? It could be worth a pretty penny to the right person. Those pumps alone, new, are probably worth over $4000 for the pair. Unless you got them cheap enough that you wouldn't likely find another deal like the one you already got, in which case I understand completely, and I am envious!

 

[XRogerX]

It should. Otherwise it would be leaking oil somewhere I think. I don't know much about them. If it was used in HVAC though, the compressor will have led a pretty easy life, if the oil was kept up.

 

[nivek]

It is quite a bit of compressor but I don't want to worry about air for a very long time! Once I get it set up, I should be good till I'm done!
The compressor it is replacing (Brunner 414) was in my grandfathers Esso garage before I was born and then eventually in my dad's shop and now in mine so I want this one to do the same.
I could have bought a 7.5hp QT new for what this is going to cost me once it is set up but I think this QS model will last longer even bought used. I bought the duplex because I wanted to have a pump extra just in case the other breaks or I need more air in the future.
To be honest, it is a lot larger than it looked in the picture!

All the arrows are pointing to the motor. The motor has a sticker pointing away from the pump, the flywheels arrow point to the motor and the oil pump arrow points to the motor. Everything seems to be inline and turning the right direction.
Anyway to test the gauges?
Strange that both pumps do the same thing?

 

[greygoat]

Just a memo; I have a large Quincy compressor,
not sure of the model..because i'd have to go out to the shop to look..bought it used 30 years ago..took of a plate..cleaned a lot of sludge
from the crankcase..suspect former owner mixed
incompatable brands of oil. I filled it to the
proper level,(it has a dipstick) with Mobil 1
5-20..its been running good for 30 years,builds
oil pressure in about 5 seconds on the gauge. It
is set for 15 PSI, so I left it there, but it
has an adjustable oil pressure valve right by the
pressure gauge.

 

[nivek]

Thanks for all the replies. I disconnected the Johnson oil shut off control and re-installed the gauge as if the controller did not exist. On start up the gauge went right to max and then settled down to 23-25psi on the gauge.
So I guess the controller stopped the gauge from reading some how.
What should the running oil pressure be set at?
Does it harm anything being at 25psi?

 

[DH in Carolina]

After looking at that Johnson Controls oil pressure safety It is a P29 low oil cutout instead of a P28 control. Works about the same.

 

[nivek]

Thanks for the correction

 

[greygoat]

Just under the pressure gauge, in your photo, is
the oil pressure relief valve..it's a bolt, with a nut on it. Loosten the nut..screw bolt IN for
more pressure, OUT for less pressure. Yours looks
just like mine. I experimented on mine, but left it at the pressure setting it came with.

 

[XRogerX]

Normally they run 15-20psi, so yours is ok.

There is a screen on the oil pick up inside the crankcase that gets sludged up sometimes too, Doesn"t hurt to clean it.

 

[nivek]

I see it. Thanks for the info. I am hoping slowly but surely I will know this compressor like the back of my hand! Just takes time and alot of good friendly info to get there.

I've read that the compressor can be set for continuous operation like for sand blasting. Can anyone tell me what is involved? Difficulty level?

Thanks

 

[Dusty MI]

When I think of continuous operating, I think of it being run with a gas engine and the compressor cutting in and out. I think to do that a valve is held open when not pumping air.

Dusty

 

[nivek]

Well I thought I had it fixed but it turns out disconnecting the no oil shutoff control was just a coincidence.
After a couple of start ups, not reading any pressure. Maybe one out of five times I will get a pressure reading but the pump will always produce air.
I don't think it is the gauge because I took the filter off and there wasn't any oil coming out when running. Took the gauge off and no oil there also.
Took the oil pump off, blew air through the passages, got pressure after that but a couple hours later I tested it and no pressure.
Took off screen and cleaned it, no change.
Looks like all cap screws are on the crank.
Going to check the O-ring on the driveshaft of the oil pump where it enters the crank but I have to take off the bearing carrier and I'd rather do this as a last resort. Can I take the bearing carrier off and easily put it back on or do I need new seal and do some shimming?
Also, have not located the oil pressure bleed valve. If this is stuck would it allow the pump to produce air without oil pressure on the gauge?

Any suggestions?

 

[nivek]

Little shy to admit this but after taking most of the oil pump and it's surroundings apart I found out that the rotation was not correct!
Somehow, with my temporary wiring, every so many start ups the motor will turn the other direction. Could have something to do with the phase converter. So when I checked it, it was turning the right way but only sometimes.
With the motor turning the proper direction the pump works 100%.

All is not lost, it was a good crash course on the oiling system!

Thanks to everyone for your input