Can a 230v3-Phase Compressor be used with household 210v

[beepbeep]

Originally Posted by Tidybuoy

BTW, what is 3 phase anyway?

https://en.wikipedia.org/wiki/Three-phase_electric_power

Three wires with AC, but spaced 120 degree apart. You can do really neat stuff with it. I am puzzled that US still does 2-phase 230V thing. Over here, 3-phase is the norm. Only very small condos get singe-phase 230V feed, everything else is 400V 3-phase. Two phase is non-existant.

My whole house is fed by 3-phase 16A fused cable. Basically everything runs on it: dryer, dishwasher, heating, hot water, hob etc. I went down from 25A and 16A fuse after converting to GSHP and still never tripped 16A fuse.

[red-beard]

Originally Posted by beepbeep

https://en.wikipedia.org/wiki/Three-phase_electric_power

Three wires with AC, but spaced 120 degree apart. You can do really neat stuff with it. I am puzzled that US still does 2-phase 230V thing. Over here, 3-phase is the norm. Only very small condos get singe-phase 230V feed, everything else is 400V 3-phase. Two phase is non-existant.

My whole house is fed by 3-phase 16A fused cable. Basically everything runs on it: dryer, dishwasher, heating, hot water, hob etc. I went down from 25A and 16A fuse after converting to GSHP and still never tripped 16A fuse.

We do not have 2 phase power in the US. Our residential 120/240 system is a safety 240V single phase, with each leg 120V to ground. Some refer to it as split phase. And we do use various 3 phase systems. My office uses 3 phase 120/208. Most three phase US is 277/480.

[beepbeep]

Originally Posted by red-beard

We do not have 2 phase power in the US. Our residential 120/240 system is a safety 240V single phase, with each leg 120V to ground. Some refer to it as split phase.

Ah, get it! a 240V transformer with middle tap earthed.

Our 3 phase has 230V between phases (which most small single-phase stuff uses) and large loads (saunas, heat pump compressors) are connected to all three phases.

[nota]

the cheap way is small 5 to 8 hp gas motor to drive the unit

[dad911]

Unless you need that capacity, I would sell it and buy one of the quiet compressors.

[red-beard]

Originally Posted by beepbeep

Ah, get it! a 240V transformer with middle tap earthed.

Our 3 phase has 230V between phases (which most small single-phase stuff uses) and large loads (saunas, heat pump compressors) are connected to all three phases.

Yes, exactly. And our "480V" 3 phase is virtually the same as your 400V. While it isn't "common", we do actually have lighting systems that use phase to neutral voltage on the 3 phase 480V (277 Volt to neutral). These will become rare soon, as companies move to LED lighting.

[bob deluke]

Don’t even bother with phase inverters. Just buy a 5 hp 230V 1ph motor and be done with it. Make sure it has a start/run capacitor as part of the package. Make sure shaft size is the same and motor baseplate is the same. Done and done.

[cmccuist]

For a 5 hp compressor you can go variable frequency drive, or rotary phase converter. you would need to buy one with a capacity of 7.5hp or 10hp for it to work reliably.

Better to just buy a 5hp 240v motor. it'll be cheaper. you need to pick one with the correct spindle to fit your pulley.

I have a 3 phase, 3 hp grinder, a 1 hp mill and a 5 hp lathe. I put in a 10 hp rotary phase converter (better than a VFD imo). I got a Baldor 10hp 3 phase motor off of FB marketplace for $75 and bought an American Rotary panel off of eBay for $230. That will power all my machines much better than individual VFD's.

5 hp is about at the limit of where I would use a VFD. VFD's are really cheap for 1-3hp mills and small lathes, but 5 hp is pushing it.

10hp 3 phase panel

[Tidybuoy]

Originally Posted by bob deluke

Don’t even bother with phase inverters. Just buy a 5 hp 230V 1ph motor and be done with it. Make sure it has a start/run capacitor as part of the package. Make sure shaft size is the same and motor baseplate is the same. Done and done.

I may go this route and be done with it. This is just for my home garage where I use very little compressed air, but I do use it from time to time. My goal was to replace my noisy De Walt compressor that takes up space in the garage and put this larger compressor outside behind my garage where I have space. I may even build a simple enclosure to protect it from the elements. I'm not opposed to spending the money on a new motor since I got this compressor for free.

It's definitely more than I need but having a few air ports plumbed to my garage will just add to my man-garage

Out of Space:

[Arizona_928]

For my well pump I have a rotary phase converter, and transformer.... Your application sounds like VFD territory. Should be cheaper, however they do make solid state phase converter. My setup ran $2200. It's easy to wire three phase too.

At the end of the day. It's a lot of extra equipment.... Pros cons. I say replace the motor with single one phase. Especially since the only real advantage of three phase is the use of higher gauge wiring, which over a giant factory is economical. At home it's nothing to run 20 ft of 8 awd.

[unclebilly]

Seriously - look at my post above. It will cost you under $175 to install a Inverter VFD and it will be way better - you can do a soft start, whatever you want. They are set up for a remote switch (read pressure switch). These things are slick.

[hcoles]

Originally Posted by bob deluke

Don’t even bother with phase inverters. Just buy a 5 hp 230V 1ph motor and be done with it. Make sure it has a start/run capacitor as part of the package. Make sure shaft size is the same and motor baseplate is the same. Done and done.

+1 on this idea

[sammyg2]

Originally Posted by Tidybuoy

. My goal was to replace my noisy De Walt compressor that takes up space in the garage and put this larger compressor outside behind my garage where I have space.

most of the noise from an air compressor comes from the intake.
My compressor was noisy as all get-out.
I rigged up an intake snorkel routed outside the garage (short with as little restriction as possible) with a filter/silencer from McMaster Carr IIRC, cut the noise in half or better.