# Old Quincy Air Compressor



## wannaBelkhuntin

I have a Quincy model 325 12 that I purchased and it has had the older 3 phase motor replaced with a 5 HP single phase motor that has 3 capacitors on it. It also has no pressure switch on it. What pressure switch should I go with ? Do I need any type of magnetic starter ? Tried posting pics but I can't seem to find them on my computer. Thx Dave


----------



## iowagold

so snap and post a few pix off the new motor tags.

most of the time if you used a good brand of motor they are direct connect.

so is the new motor single phase 240 vac? or is it 120 vac?


----------



## wannaBelkhuntin

This is an older 5 hp meaning probably equivalent to a 10 hp today. This is the only pic I have, I tried several times yesterday to upload pics but can't get them onto my computer. There is no name plate on the motor. May have been lost when it was rebuilt. Sorry this is all I have. The guy I bought this Quincy from had the compressor checked out and had a shop swap out the 3 phase motor for this single phase motor. It supposedly ran when he got it back but drew to much power from his limited Electric. 100 A service to a 3000 sq ft home... Thx Dave


----------



## wannaBelkhuntin

I also have a new pressure switch from a Ridgid air compressor I used for work, would I be able to use that ?


----------



## iowagold

well the 3 bumps are mostly 3 phase from what i remember..
click here for a maybe motor
but it could be something different form a standard baldor motor..


----------



## wannaBelkhuntin

Well they are capacitors that help start a motor, they store electric energy that helps create torque when the motor starts. The motor you linked to has capacitors and it is a single phase motor. I have not seen capacitors on a 3 phase motor. These are found on most single phase motors, some are start capacitors and some are run capacitors.
So back to my original question do I need I need a magnetic starter ? I just did research on Google for this and found a video from Compressor-source.com explaining why/when you need a magnetic starter. In my case I still need the pressure switch, but it will now be connected to the starter to turn on the motor. Thx Guys.


----------



## stevon

wannaBelkhuntin

The capacitors shift the phases to get more torque during startup and used also when running as well. I would think that the 100 amp service could be a problem in starting this compressor motor. The 5 HP startup LRA (locked rotor) is greater than 100 amps, even without the other household loads. 










If you only have two wires to connect power to, you are looking at a single phase motor in most cases. But without a nameplate you don't know at what voltage, full load amps and other information. I would talk to an electric motor rebuilder and see if they can help identify what you have.

Stephen



wannaBelkhuntin said:


> Well they are capacitors that help start a motor, they store electric energy that helps create torque when the motor starts. The motor you linked to has capacitors and it is a single phase motor. I have not seen capacitors on a 3 phase motor. These are found on most single phase motors, some are start capacitors and some are run capacitors.
> So back to my original question do I need I need a magnetic starter ? I just did research on Google for this and found a video from Compressor-source.com explaining why/when you need a magnetic starter. In my case I still need the pressure switch, but it will now be connected to the starter to turn on the motor. Thx Guys.


----------



## stevon

wannaBelkhuntin,

You might want to consider putting a belt guard on your compressor as well for safety concerns, the fan motion can suck in stuff. At least make sure there is no physical access to compressor if you run it this way for other people, kids, cats, dogs etc.

Stephen


----------



## wannaBelkhuntin

stevon said:


> wannaBelkhuntin,
> 
> You might want to consider putting a belt guard on your compressor as well for safety concerns, the fan motion can suck in stuff. At least make sure there is no physical access to compressor if you run it this way for other people, kids, cats, dogs etc.
> 
> Stephen


Well first off the 100 amp service was for the PREVIOUS owner, as I previously said his service could NOT handle this compressor. As far as the motor being single or 3 phase, the previous owner had the original 3 phase removed and had a single phase 5 HP motor replacing it.
As far as the guard is concerned this compressor is going to be mounted on a platform outside of my garage and then enclosed so there will be no random access to it.
So after all of that can you offer any assistance on my ORIGINAL questions ???


----------



## iowagold

look in to a motor drive...
that will help with the ramp up and lower the in rush.
the better units have a pressure sensor.

yea an digital un loader is a must on these larger units..
that will help on lockup and super hard starting..
they can be set to freewheel the compressor for a min or so to let the fly wheel come up to speed.
then connect the output to the directional check valve to the tank.

seek out a local motor service place.. they can help you on the motor drive as well as all of the other electrical parts.


----------



## wannaBelkhuntin

So what is this locked rotor chart ? Is this similar to start up amperage vs running amperage ???
I know the original owner mentioned this set up drawing 37 Amps, I would have to guess that was at start up.


----------



## iowagold

well you need the tag off the motor to see the real motor data.

reach out to the former owner..
see if you can find where the motor was purchased from.
and what date..
then contact that vendor for maybe a receipt of what was purchased..
maybe then you will have a make and model of the motor and can look up specs.

we need to know the current to get a HD pressure switch...
yea depending on the motor a contactor might be needed in a start box
and then use a basic pressure switch to control the relay.
try this link below for the parts;
click here for the air compressor parts page


----------



## stevon

wannaBelkhuntin,

Sorry about getting side tracked, I would recommend using a magnetic starter as your pressure switch contacts will not be able to handle the LRA or "inrush" current of a 5 HP motor. To control a "remote type" magnetic starter you could use almost any pressure switch. Just make sure that the magnetic starter is rated for the HP of your motor and that it has the remote control feature. There are cheaper magnetic starters that are manual start only, don't buy one of those

Stephen


----------



## stevon

wannaBelkhuntin,

The LRA chart shows just how much power is needed when switch is turned on with an electric motor load. It displays based on electric motor HP, how much power is drawn just before the rotor starts to turn. The rule of thumb is that RLA is 6 times the full load running amps. that's why you would need a 30HP+ gas generator to start this compressor. 37 amps was drawing too much power for this motor, probably voltage drop was so bad that motor was almost stalling and drawing so much power. I'd be curious to see what voltage he was drawing 37 amps! at that current it would soon overheat anyways

Stephen



wannaBelkhuntin said:


> So what is this locked rotor chart ? Is this similar to start up amperage vs running amperage ???
> I know the original owner mentioned this set up drawing 37 Amps, I would have to guess that was at start up.


----------



## stevon

wannabelkhuntin,

This is what you need: 









5 HP Single 1 Phase Magnetic Starter Motor Control 220-240 Volt 22-34 Amps | eBay


Find many great new & used options and get the best deals for 5 HP Single 1 Phase Magnetic Starter Motor Control 220-240 Volt 22-34 Amps at the best online prices at eBay! Free shipping for many products!



www.ebay.com





Stephen


----------



## wannaBelkhuntin

5 Horsepower Single Phase Electric Magnetic Air Compressor Motor Starter Switch MSP30T Starter I have chosen

SQUARE D Single Port 135-175 PSI Air Compressor Pressure Switch 9013FHG42J59M1X Pressure switch I have chosen


----------



## stevon

wannabelkhuntin,

Looking closer at the motor pictured it may be more than 5 HP, 7.5 HP to 10 HP is my guess

Stephen


----------



## wannaBelkhuntin

I have no reason not to believe the person I bought it from. Based on physical size yes it is big, but I had an even older compressor with an even bigger 5 HP motor so size doesn't concern me. I have a newer Coleman compressor in my shop now and the 5 HP motor is half the size of this one. So I am ordering the parts listed above for it. The worst that can happen is the contacts on the starter take a crap sooner. The POS Coleman in my shop now operates off the pressure switch. Thx again guys


----------



## stevon

wannabelkhuntin, 

Sounds like you have things sorted out. The POS Coleman 5 HP is probably a "bogus" or "peak" 5HP motor drawing only 15amps FLA @ 230volts or in layman's terms an actual 3HP output. The contacts on the pressure regulator can handle a 15 amp, 3HP output motor. 20 amps or more at 230 volts is what a real 5 HP electric motor would draw. Keep us posted on how you make out, have fun!

Stephen


----------



## iowagold

hey stevon how about an easy start soft start on the shop air compressor motor?
they work on air cond compressors for hvac...


----------



## stevon

iowagold

I don't think or at least I don't know if wannaBelkhuntin is having starting issues with this compressor. So why would he spend unnecessary effort and money on a soft starter system if he is having no problems? He said that the *previous* owner had problems.

Stephen




iowagold said:


> hey stevon how about an easy start soft start on the shop air compressor motor?
> they work on air cond compressors for hvac...


----------



## stevon

iowagold,

When he gets this running I would like to know the full load running current checked with an ammeter on one leg. That will tell us what HP the motor is putting out.

Stephen



iowagold said:


> hey stevon how about an easy start soft start on the shop air compressor motor?
> they work on air cond compressors for hvac...


----------



## wannaBelkhuntin

Hi Stephen, I know it's been a while but here goes.... I haven't touched this since getting my starter and pressure switch. I stopped at the blue store and looked at a piece of wire [ 6/3 X 125'] and the price doubled to 269.00 then went to 369.00 then to 469.00 and is now 529.00 all in the past year !!! This is needed to get enough power from my house to my garage. I am seriously considering spending a couple of dollars more for a used compressor with a gas engine. I do have another question that I don't know if you can help with. On this Quincy it has some type of valves on the cylinders that I believe are some type of decompression valve to make it easier to start, any thoughts on that ? Thx Dave


----------



## stevon

Dave,

Yes I believe they are part of a centrifugal unloader. I think that the compressor can be run on a lower power electric motor at a slower speed. With the original specs on the pump you can find the slowest speed and lowest actual HP motor that can be used. Buying an efficient modern electric motor could lower your LRA at startup. Did you take any measurements of current while running this compressor? you may just have some bad windings or start circuit problems. It's always hard to fix "someone else's" problems when buying used equipment, it's hard to figure out what questions to ask and to solve.

Stephen



wannaBelkhuntin said:


> Hi Stephen, I know it's been a while but here goes.... I haven't touched this since getting my starter and pressure switch. I stopped at the blue store and looked at a piece of wire [ 6/3 X 125'] and the price doubled to 269.00 then went to 369.00 then to 469.00 and is now 529.00 all in the past year !!! This is needed to get enough power from my house to my garage. I am seriously considering spending a couple of dollars more for a used compressor with a gas engine. I do have another question that I don't know if you can help with. On this Quincy it has some type of valves on the cylinders that I believe are some type of decompression valve to make it easier to start, any thoughts on that ? Thx Dave


----------



## stevon

Dave,

The original picture shows a large drive pulley on the replacement motor for this compressor. Are you sure the drive pulley size is correct for this pump? If he had a 10 HP 3 phase motor and just reused the original pulley on a smaller 5HP motor, there would be all kinds of problems, over load, over current, motor stalling, etc.
what is the pump model number, HP and speed and FLA of the motor used?

Stephen



stevon said:


> Dave,
> 
> Yes I believe they are part of a centrifugal unloader. I think that the compressor can be run on a lower power electric motor at a slower speed. With the original specs on the pump you can find the slowest speed and lowest actual HP motor that can be used. Buying an efficient modern electric motor could lower your LRA at startup. Did you take any measurements of current while running this compressor? you may just have some bad windings or start circuit problems. It's always hard to fix "someone else's" problems when buying used equipment, it's hard to figure out what questions to ask and to solve.
> 
> Stephen


----------



## wannaBelkhuntin

I must admit this compressor has never been run by me because i don't have an adequate power supply in my garage. I have no idea on motor draw or anything else, just what the person I bought it from told me. I have no reason to doubt him as he seems to be on the higher scale of pay judging by his house and cars. He told me he had everything done by a local repair shop so it wasn't something just hacked together by himself. I realize that they could have hacked it also but I really believe this guy had no problem paying to have it done right. As you stated earlier his issues could have been caused from his lack of available power as he only had a 100 A service and the panel was at the opposite end of a fairly large house that I don't believe 100 A service was adequate for the size of his house let alone adding this compressor to the load. Any thoughts on the gasoline powered compressor ? It is a Rolair 18.4 CFM with a Honda engine. I would need to change the tank but I have the tank from my Coleman that has since blown the belt so to me it is only good for parts. Thanks guys.


----------



## stevon

Dave,

That Honda GX 270 is not enough HP to run your Quincy compressor head, and I still don't know what model pump head you have. Rule of thumb is 2 to 1 for the ratio of gas vs electric motors, the difference is that a 5HP electric motor can produce greater HP when needed for a short period of time before is over heats, 10HP or even 15HP is possible to get out of an 5HP electric motor before it stalls. This is not true for the peak (at maximum rpm) 5HP gas motor, draw 6HP and it will stall. So to be safe a 10HP to 16HP gas motor is needed for a replacement for an electric 5HP electric motor run at the same speed. You will also need to install an Idle control valve for a gas motor.
See this article:

Electric to gas motor conversion equivalent - Tool Talk Forum 

Stephen


----------



## stevon

Dave,

Maybe I misunderstood your question. Yes you could move the gas setup, motor, pump, belt, idler control valve, etc. to the larger tank. I would buy a new over pressure valve (maintenance item), the 125 to 150 PSI version, not the original 175 to 200 psi. Do you know anybody knowledgeable about compressors to help with the conversion? 

Stephen



stevon said:


> Dave,
> 
> That Honda GX 270 is not enough HP to run your Quincy compressor head, and I still don't know what model pump head you have. Rule of thumb is 2 to 1 for the ratio of gas vs electric motors, the difference is that a 5HP electric motor can produce greater HP when needed for a short period of time before is over heats, 10HP or even 15HP is possible to get out of an 5HP electric motor before it stalls. This is not true for the peak (at maximum rpm) 5HP gas motor, draw 6HP and it will stall. So to be safe a 10HP to 16HP gas motor is needed for a replacement for an electric 5HP electric motor run at the same speed. You will also need to install an Idle control valve for a gas motor.
> See this article:
> 
> Electric to gas motor conversion equivalent - Tool Talk Forum
> 
> Stephen


----------



## MacMcMacmac

Yes, you need a motor starter. Be sure you have the power to properly operate that Quincy. It is more compressor than you will run on household supply unless you under drive it as a 2hp maybe 3hp compressor. Still worth it if you didn't overspend. It will last forever.

There are 2 redundant constant run pilot valves piped into the controls that are not needed and improperly installed. Once this is rectified you will have a completely loadless start. You do not need any fancy soft starts if you have adequate power service and wiring .

That Quincy is the finest reciprocating compressor ever built and is ten times the machine that Rolair is.


----------

