pamike
Well-known member
Do the static style phase convertors work fine for air compressors or should I go with a rotary style? Looking to run a 1 HP 3 phase motor.
Phase Convertor for air compressor
- Thread starter pamike
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motofool33
Well-known member
from what ive researched they are not very power effecient when you do that and you need a converter 3x the size of your intended output. i cant see building buying one that is cheaper then a 1hp single phase air compressor?
what kind of air compressor are we talking about?
what kind of air compressor are we talking about?
theoldwizard1
Well-known member
Just buy a single phase motor and resell the 3 phase one on CL.
kazlx
Well-known member
You are best off replacing the motor with a single phase. A 1HP is cheap. You would be spending more money trying to run the 3ph motor than just digging up a used motor. Air compressors have some special requirements for phase conversion. For your application, it doesn't make sense.
Mr. T
Well-known member
Something like this maybe?
http://www.automationdirect.com/adc...l)/GS1_Drive_Units_(120_-z-_230_VAC)/GS1-21P0
http://www.automationdirect.com/adc...l)/GS1_Drive_Units_(120_-z-_230_VAC)/GS1-21P0
motofool33
Well-known member
I just typed in ebay 99$ for a 1hp single phase motor, I'd go that route
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kazlx
Well-known member
VFDs don't work well for compressors, because they have to turn on and off on demand. The compressor demands when it needs to turn on and off based on the pressure switch. It's not like a mill or lathe where you can use the VFD to start/stop the machine at will.
Yeah, I was thinking of just going to a single phase motor...heres the catch...
Its a dual pump/motor setup so you need 2 motors. Also there is a control box that you can select to alternate the motors, or run either one exclusively. I assume that whole box would have to be rewired if its converted to single phase...
Its a dual pump/motor setup so you need 2 motors. Also there is a control box that you can select to alternate the motors, or run either one exclusively. I assume that whole box would have to be rewired if its converted to single phase...
motofool33
Well-known member
yea gonna have to rewire the box, but also if you phase convert them you have to double the capacity cause it has to run 2x 1hp motors.
i would put in two 1hp motors single phase, and rewire the box if it was me.
motofool33
Well-known member
So where's the pics of the setup? What model is it?
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Mr. T
Well-known member
VFDs have been used on air compressors for a long time. It might take some thinking on the control side for the pressure switch but there is nothing inherently wrong with it.
Is the one I posted the best one to use? Probably not. Double the HP rating, why not?
I also work on many machines of varying size that use VFDs "on demand."
Mr. T
Well-known member
I'm in a secret location near the middle 
Kazlx is correct that a single phase motor for your use is pretty cheap. Mounting and speed and all of that has to be worked out but it could likely be cheaper.
Just chimed in to say that there's more than one way to skin a compressor.
Kazlx is correct that a single phase motor for your use is pretty cheap. Mounting and speed and all of that has to be worked out but it could likely be cheaper. Just chimed in to say that there's more than one way to skin a compressor.
The output of a VFD is only three phase, for use w/ 3Ø motors only.
theoldwizard1
Well-known member
Just don't hook up 2 of the phases. 1 phase in, 1 phase out for both of the motors. Wire neutrals and grounds together for motors and inputs.
alfredeneuman
Well-known member
Nothing will run if you don't hook up 2 of the phases. Nothing runs on 1 wire.
You need 2 wires to get single phase power.
"Wire neutrals and grounds together for motors and inputs."
Please explain this. (The only place where you are supposed to have the neutral connected to ground is at the main service.)