SA6 to SA3

[divezonescuba]

Any reason why I might not be able to convert an SA6 to an SA3 by changing out to a smaller motor? I am trying to put a compressor on my sailboat and the generator cannot handle the SA6 motor.

 

[tbone1004]

the compressor head itself is a lot smaller so the SA6 can probably be run with a 3hp motor, but it may not get all the way up to pressure and it will have to run real slow. Much better off trying to sell the 6 and buy a 3... Or convert the 6 to gas, or to a belt drive off of the onboard motor

 

[iain/hsm]

Any reason why I might not be able to convert an SA6 to an SA3 by changing out to a smaller motor? I am trying to put a compressor on my sailboat and the generator cannot handle the SA6 motor.

I guess suggesting again using a professional compressor engineer for the task isn’t going to be agreed with by some, but failing that
knowing your exact generator performance and capability would have helped. But no reason whatsoever why you can’t put on a smaller motor. The SA series are the only compressor blocks you can reduce speed with to suit your motor start current without damaging the compressor.

With the SA-3 as an example changing out for a smaller motor
Using 230 Volt single phase
2.0 BHP 1.40 Kw Run at 1725RPM 230Volt 2.2 SCFM At 3300psi Belt size AX35 Plug Nema 6-150P 12.5 Amps

Using 115 Volts Single phase
2.0 BHP 1.40 Kw Run at 1725RPM 115Volt 2.2 SCFM At 3300psi Belt size AX35 Plug Nema 5-30P 26 Amps
1.5 BHP 1.10 Kw Run at 1265RPM 115Volt 1.6 SCFM At 3300psi Belt size AX35 Plug Nema 5-20P 21.0 Amps
1.0 BHP 0.75 Kw Run at 865RPM 115Volt 1.1 SCFM At 3300psi Belt size AX34 Plug Nema 5-15P 16.0 Amps

Using 3 phase (230 Volt)
3.0BHP 2.20 Kw Run at 2300RPM 230Volt 3.0 SCFM At 3300psi Belt size AX36 Plug None DOL 8.4 Amps

I will leave you to work out each drive pulley size as they are each based on the motor speed data plate and vary
depending on motor speed and vendor. But if you have the data plate info I can calculate out for one.
I would suggest using a capacitor start/cap run motor for the single phase and good quality brands not direct from China or Ebay.
In the US Baldor, Leeson etc are OK. Others may differ.

 

[divezonescuba]

I was afraid that it might be complicated.

Thanks for the info.