RIX SA-3E Compressor 60Hz Motor Drive Configurations

[iain/hsm]

Been meaning to do this for a while.
To show the various flow and RPM adjustments for a range of motor sizes ranging from 1 BHP to 3 BHP on the Rix SA-3E compressor.

Please note the RPM's listed below are the pump or compressor RPM's (NOT the Motors)

1.0 BHP at 865 rpm Flows 1.1 SCFM with 115 Volt 1 Phase, 16.0 AMPS Belt AX-34 Plug NEMA 5-15P
1.5 BHP at 1265 rpm Flows 1.6 SCFM with 115 Volt 1 Phase 21.0 AMPS Belt AX-35 Plug NEMA 5.20P
2.0 BHP at 1725 rpm Flows 2.2 SCFM with 115 Volt 1 Phase 26.0 AMPS Belt AX-35 Plug NEMA 5.30P
2.0 BHP at 1725 rpm Flows 2.2 SCFM with 230 Volt 1 Phase 12.5 AMPS Belt AX-35 Plug NEMA 6-15P
3.0 BHP at 2300 rpm Flows 3.0 SCFM with 230 Volt 1 Phase 16.5 AMPS Belt AX-36 Plug NEMA 6-20P
3.0 BHP at 2300 rpm Flows 3.0 SCFM with 230 Volt 3 Phase 8.40 AMPS Belt AX-36 NO Plug
3.0 BHP at 2300 rpm Flows 3.0 SCFM with 460 Volt 3 Phase 4.20 AMPS Belt AX-36 NO Plug

Later I will work out the varoius driver pulley sizes for the most suitable motors running 2 pole 3450/3600 RPM at 60Hz And at 1725/1800 RPM running at 4 pole. These are the motors RPM to avoid confusion.
The lower RPM is at the approximate rated load on the motor and the higher RPM is at the synchronous speed with no load on the motor. The diameter size of the driver pulley will ensure the correct RPM at the compressor pump.

Not quite got them running on pure sunshine (solar) but I'm getting there.
Also IMHO anything less than 1 SCFM is frankly a step too far in the wrong direction.
Hope the NEMA plug sizes listed are OK as I'm a tad rusty on Yankee electrics.
Hope it's useful Iain

 

[tbone1004]

@iain/hsm have you plotted any chart like this on the SA6? I assume CFM vs. amps will be the same, but was curious about the RPM's

 

[iain/hsm]

Not yet been busy on other stuff, but just noticed above I still need to calculate out the pulley sizes for the SA-3. Not been much interest in the thread but I regarded it more as a placement of informtion that divers may wish to consult when they are considering an alternative compressor. It was done really to address the consideration that the more informed you are, the better the choices you make, kind of thing.

As far as the SA-6 is concerned the nominal build delivers 6 scfm at 1514.87 RPM and to compress at a 5000psi dischage pressure you will need 4.87 BHP (3.63Kw)
Assuming you are compressing ambient air at 14.7psia altitude and at a 70 DegF ambiant air temperature.

The SA-6 will displace 3.07 CFMD Displacemet at 600RPM

But for a ball park if you use double the flow as a rough guide from the SA-3 chart I just need to do the Kw power requirements. Some time. Regards Iain

 

[tbone1004]

@iain/hsm reason I was asking is it looks like the SA3 runs at much higher RPM than the SA6. I'm leaning towards putting a 4:1 pulley on mine which has a 1.5hp 4-pole motor at 1800rpm which should allow the motor to run at full RPM with the compressor matching the power requirements.