compressor RPM

[dannyp]

i have an ingersol rand type 30 model 242 compressor without a motor
today i have been and bought a 5hp singel phase motor to run it.

what i'm not quite sure of is the optomum pully size to go for as amount of power required to drive the compressor to diffrent pressures at diffrent RPM's varys

the motor i have is 1420 rpm 5 hp 3.7 KW the compressor is 175 psi capable but 125 psi is plent for me.

i've sort of guestimated that the compressor will need about 5hp at 750 rpm but not 100% sure dose anyone have or know where i can find any load maps for it ?

 

[eil]

I have a three horse on mine but cant remember the size of the pulley, I will check tomorrow for you. I was told the max rpm should be 1040.

 

[graffian]

If it's the pump that's usually driven with the 5hp three phase motor[big cylinder is 5" bore] they usually have three belts and the motor pulley is around 6 inches.

 

[ford34/2]

242

heres a pic of a 242 pump, guessing about a 14" pully,

I have 234 pump but different spec altogether,

Stan

5Hp on single phase, some amps to start that up.

 

[tigler]

The type 30 was produced in various capacities and all will have a rated speed, all thats needed is someone to advise the rated speed for your particular type 30 spec.

 

[langy]

Blimey thats gonna pull a few amps on startup !!!

i have an ingersol rand type 30 model 242 compressor without a motor
today i have been and bought a 5hp singel phase motor to run it.

what i'm not quite sure of is the optomum pully size to go for as amount of power required to drive the compressor to diffrent pressures at diffrent RPM's varys

the motor i have is 1420 rpm 5 hp 3.7 KW the compressor is 175 psi capable but 125 psi is plent for me.

i've sort of guestimated that the compressor will need about 5hp at 750 rpm but not 100% sure dose anyone have or know where i can find any load maps for it ?

 

[eil]

Mine is a 242, 4" x 2 1/2" x 2 3/4", that is first stage, second stage and stroke. the motor pulley is 7" OD and the compressor is 15" OD, It has a 3hp motor on it, the RPM of the compressor is 650 just before cut off pressure of 145 psi. Hope thats of some help for you.

 

[dannyp]

Mine is a 242, 4" x 2 1/2" x 2 3/4", that is first stage, second stage and stroke. the motor pulley is 7" OD and the compressor is 15" OD, It has a 3hp motor on it, the RPM of the compressor is 650 just before cut off pressure of 145 psi. Hope thats of some help for you.

that is the magical bit of information thankyou very much.

on a crowbar calulation i can gestimate that 3 hp @ 145 psi = 650 rpm therefore 650 / 3 = 216
216 * 5 = 1083 rpm.

i've had it running today with a 7 1/2 inch OD pully on and that flys round happily so i'm going to try and get a bigger one

oh and startup amps hell yes it pulls some. 13A fuse pops starting an unloaded motor and the lights flicker when its running atm. so next weekends job is 10mm cabel out to the workshop

 

[eil]

More info here
http://www.ingersollrandproducts.com/air/catalogs/AP/Single & Two stage Reciprocating_English.pdf
http://www.mbairsystems.co.uk/Downloads/compressors/T30_Rationalised_eng.pdf