Quincy 2 Stage 310 Help

[turbosl2]

I have an older 310 2 stage compressor mounted on an 80 gallon tank. It has always been slow to build pressure in the tank (15mins). I believe it was always due to the older slow speed motor and pulley ratio i have.
Compressor =14"
Motor = 4"
Motor speed = 1725
RPM at compressor 492

The compressor is about 4cfm at this speed and will do almost 10 at 920 rpm.

Question is, how do i calculate how much HP i need for this compressor. It has hydraulic unloaders in which the compressor wont build until oil pressure is up (reducing the starting requirement for sizing your electric motor)

 

[American Locomotive]

From what I can tell, 3HP would be about the bare minimum for 10 CFM. So you'd probably want a 3.5 or 4HP motor for a bit of safety factor.

 

[toplessHO]

single or 3 phase power?
see my thread in the electrical forum
Tractor Supply 6 HP for $300
I got the extended warranty ,3 additional years for $30(total of 4 yrs)
probably wont need that big ,but oversized it should last forever.
you're doubling RPM of motor speed so using same size pulley it will double the compressor RPM.

 

[turbosl2]

This is 220V single phase. How do you calc the HP requirement. I was told the unloader system woudl require less HP because it helps with ease of start. What would happen if i end up with an undersized elec motor?

 

[toplessHO]

please read my thread it will answer those questions
current HP should be listed on motor tag
if you double the speed it will take more HP

 

[turbosl2]

Do you have a link to your thread? Motor is to old with to much paint to see any tag. Its HUGE and from the 60s

 

[toplessHO]

https://www.garagejournal.com/forum/showthread.php?t=364682

 

[turbosl2]

https://www.garagejournal.com/forum/showthread.php?t=364682

Thanks i actually did read this but it didnt really tell me how to pick a HP motor for my compressor. It was more dealing with HP ratings and voltage drop. I may email Quincy

 

[cvairwerks]

The stuff I found showed the 310 to be driven by a 2 hp motor, with a pump speed of 400-920 rpms.

 

[turbosl2]

ok nice, that sounds good. Thank you. 920 is where i want to be

 

[toplessHO]

I would still up the HP
cant hurt ,it will only draw as much power as is needed
2 HP seems pretty small for a 2 stage compressor
tractor supply had smaller ones too

 

[rnscustom]

400-920 seems like a wide range , did it tell the rpm of the motor . My ir has a 13 and a 4 pulley on the motor and it's a 3540 rpm motor

 

[turbosl2]

400-920 seems like a wide range , did it tell the rpm of the motor . My ir has a 13 and a 4 pulley on the motor and it's a 3540 rpm motor

Your spinning your compressor at 1061, my quincy cant go that fast.
The range i am told is the low end is for filtration and the upper is for mechanics...etc.

Quincy got back to me and indicated 3HP is what i want to be at for my 310.