Quincy 310 - 23 motor

[dalegregg]

Hi. New to this site, but stumbled over some Quincy wisdom from this forum, and thought I might ask: The motor in my Quincy 310 - 23 recently burnt up ... like, sparks and smoke. So, I'm looking to replace the motor, but the spec. plate is missing from the motor, so I'm not sure what to look for. Can't seem to find anything about the motor that it came with. One source says it was designed to be run by a 2 hp motor, another source says a 3 hp motor. Does anyone have confident knowledge as to what hp motor I should be looking for to drive this thing? Thank you!

 

[HFJ]

(quoted from post at 17:14:56 07/02/23) Hi. New to this site, but stumbled over some Quincy wisdom from this forum, and thought I might ask: The motor in my Quincy 310 - 23 recently burnt up ... like, sparks and smoke. So, I'm looking to replace the motor, but the spec. plate is missing from the motor, so I'm not sure what to look for. Can't seem to find anything about the motor that it came with. One source says it was designed to be run by a 2 hp motor, another source says a 3 hp motor. Does anyone have confident knowledge as to what hp motor I should be looking for to drive this thing? Thank you!

hi dale, and welcome

this parts manual says 2 HP.

 

[dalegregg]

Thanks for your reply. I expected a bigger motor, 'cuz the one I took off is HEAVY. I mean, I can a 100 lb bag of sugar to my shoulder, but I can't lift this motor more than a foot off the garage floor. I appreciate your input. - dale.

 

[jniolon]

(reply to post at 15:14:56 07/02/23)

I've got an old old quincy 310 from the 50-60's here's some facts from on old old factory quincy guru


QUINCY 310 COMPRESSOR

2 stage unit

produces 4 cubic feet for each h.p. of motor

i.e. 2 h.p. motor would produce 8 c.f. output

optimum compressor speed is less than 900 rpm (normally
run 400-900)

will produce 500 psimost run at 150-175 psi

change oil every 90 days use nd 30 wt
3 pints

notes

" sand blast orifice will use 103 cfm at 100 psi


I'm running 5 hp (heavy commercial motor) so by his calc I'm getting +/- 20 cfm but I don't think that's realistic with this pump

my shutoff is set for 125#s

john

 

[dalegregg]

John: thank you for some VERY useful information.

 

[504]

For weight, remember some of those old motors were
made from cast iron and the latter are made from
pressed steel.

 

[Steve@Advance]

There are several clues you can use to make an educated assumption on the
motor.

The things you need to know...

The frame number: Go online and find a 'NEMA Frame Chart'. Take the
measurements from the original motor and compare them to the dimensions
on the chart. That will give you the frame number.

Phase: It will be either a single phase, which uses 2 line wires and a
ground, or a 3 phase, which uses 3 lines and a ground.

Once you determine the phase, look at a FLA (full load amp) chart. If it
is a 3 phase, there should be a overload protection relay, which would
have either heaters with numbers that can be crossed, or an adjustable
heater block. Look at the setting and compare that with the FLA ratings.
If it is a single phase, look at the size of the breaker. A 2-3HP will
run on a 20 A breaker, a 5 HP would need a 30A. But these are only clues,
not absolute numbers to go by.

RPM: Do some reverse engineering, look at the diameters of the pulleys
and calculate what RPM the motor needs to turn to give the compressor the
proper speed, around 900RPM or less. Most likely it will have a 1750 RPM
motor.

Whatever choice you make, once installed, the running amps needs to be
checked with an amprobe. If drawing over the rated amps, it will
overheat. If under, it will not harm the motor but will not be fully
efficient. A larger motor pulley will bring it up. With a properly sized
motor and pulley the motor will run right at but not over the FLA rating.

 

[Destroked 450]

Quincy 310 is rated for 1.5 - 3 hp. The more hp the larger the drive pulley is to run the pump faster for more cam

Measure the motors shaft size, the more hp the motor is the larger the shaft is
My Quincy 325 has a 5 hp motor with a 1 1/8 inch shaft
With the 5 hp motor spinning the pump 900 rpm it produces 18 cfm at 175 psi

Your 310 with a 3 hp motor spinning the pump at 920 rpm will produce 9.6 cfm at 175 psi

A motor larger than 3 hp will not make it pump more cfm
Spinning the pump faster than the max recommended 920 rpm can result in severe damage to the pump

 

[hd6gtom]

Whatever motor you buy, make sure it is
rated for air compressor use. I found that
out when I owned my tire shop.

 

[caterpillar guy]

the slower you can run the compressor speed wise the longer the compressor will last. You want to keep the 175 PSI if you can as that will help with not being in that limbo spot between off and on with the pressure switch. Some will say BS I've been there to many times with tires to not want that pressure. A 1750 motor will need about a 3 inch on the motor and around 12 inch on the compressor shaft or measure your compressor pulley and then see what they have on the motor you took off. MOst places that show motors for sale will list farm duty and compressor duty motors without having to worry about the frame size. An Air over frame will work a better choice would be an air inside motor if you have a lot of mice and such that can get to the motor I would put a screen over the ends to keep them out or use the air over motor. They will be listed as such.

 

[Destroked 450]

The rpm s I listed are Quincy s recommended speed for the motor hp I listed
At those rpm a Quincy compressor will last for many years, mine is a 72 model
I set mine to operate between 120 and 150 psi, doesn t work the pump as hard to make the extra 25 psi

I assume the air over motor you mentioned is the TEFC design
Totally Enclosed Fan Cooled
That s what I have on mine and what we used exclusively at the lumber mills
Got better service from them than from the open frame design