help me identify this compressor

[tawan45]

I need help identifying this compressor.

Also it did come with a 3-phase 7.5 hp motor at 1725 rpm

16" pulley on the compressor block 6" pulley on the motor.
If i did my math right that gives me compressor rpm at 646 and 20 hp at the flywheel

If i change it to a 1phase 5hp motor at 3500 rpm with a 3" motor pulley
that gives me a compressor rpm of 656 and 26.65 hp at compressor flywheel

Maybe hp is not the correct term but that is how the motors are rated.

any help will be greatly appreciated

 

[captain]

Might be a Worthington, maybe a V2 A4

 

[BRT]

Speed doesn't change the HP at the flywheel, just the torque.

 

[tawan45]

is this the Worthington V2 4A

 

[tawan45]

i guess i need to convert HP at rpm to torque then calculate the pulley reduction.
to give me torque and rpm at the flywheel .

 

[BRT]

HP = torque in ft-lb times rpm divided by 5252. Means that at 5252 rpm torque and horsepower are the same.

 

[tawan45]

i used this pulley calculator http://www.blocklayer.com/pulley-belteng.aspx
and this torque calculator Rotating Horsepower Calculators - Horsepower, Torque, Speed
http://www.calculatoredge.com/new/horsepower.htm#torque
and i came up with 60 ft-lb @ 646 rpm with the 3phase
and 42 ft-lb @ 656 rpm with the single phase motor

so i am short 20 ft-lb at the flywheel

 

[BRT]

5252 divided by 656=8. 8 times the 2 1/2 hp that is missing is your missing 20 foot lb.

If you really need 7.5 HP to run at that RPM then 5 will not do it. The easy option is to reduce your compressor speed so long as it will run at the lower speed without oiling problems.

 

[sealark]

Why not just get a 7.5 HP single phase and keep the compressor at it's rated RPM like it was designed for.

 

[mbsdiver]

To make things simple with the pulley RPM and stuff like that do a Google search for a calculator there's one out there