# Converting 3 phase Delta UniSaw 34-450 to single phase?



## SweetTea (Aug 5, 2016)

Hey guys, I just picked up a Delta/Rockwell UniSaw model 34-450. The problem is that it is 3 phase and my shop is single phase. I would like to know if I can find a single phase motor that would bolt right up without and modifications? If so, where can I find one? I am not interested in building a VFD, but, if I could find one that is already built and if it could handle this 3HP saw for under $300 I would definitely consider going that route.


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## Nubsnstubs (Aug 30, 2013)

When I shut down my shop back in '92, my saw was 3 phase. I actually made up a 56 base that would mount onto the bracket that the saw has. I had a 2 hp motor that was used until it died. I then wanted a more powerful motor, and had to make up another motor bracket. If I can find the smaller one, I'll post a picture of it. It cost less to make than buying a single phase motor. ....... Jerry (in Tucson)


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## wapakfred (Jul 29, 2011)

Unisaw motors are readily available, but they can be expensive (figure $500 +/-), just do a search on them. But you can add a commercial VFD and use the one you have….I'm fairly certain Brad will be along with all the details.


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## Carloz (Oct 12, 2016)

Any 3 phase induction motor can be run from a single phase with a starting or running capacitors or both. Expect loosing about 1/3 of power if you use a running capacitor, more if you do no not.
There are tons of information how to connect the motor. Like here:

https://www.electricneutron.com/electric-motor/use-three-phase-motor-single-phase-power-supply/
For a table saw I would not bother with a starting capacitor as the starting torque is not that important. On contrary you will get a kind of slow start feature if you are not using it.


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## SweetTea (Aug 5, 2016)

I did not realize that a UniSaw motor would be that expensive. Are there any places that sell pre made VFD's that are less than $500? If so, what kind would I need for this saw, and how much do they cost?


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## Loren (May 30, 2008)

Unisaws use a proprietary motor mount.
You can buy an aftermarket adapter:
http://www.renovoparts.com/43-802-motor-adaptor-bracket-for-right-tilt-unisaws/

Rotary phase converters have a reputation
for outlasting VFDs. You can build a 5hp
rotary converter for about $300 using a
Phase-craft panel and a $100 3ph idler
motor.


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## 01ntrain (Jun 21, 2015)

As a "pre-made VFD", there is no such thing. It's just that….a VFD. What's needed are the correct specs and wiring it properly. In this case, what it's essentially doing is acting like an Inverter. Do a search, and there are several threads about the conversion, along with Brad's recommendations. If I remember correctly, they can be had for less than the $300 that you mentioned.


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## wapakfred (Jul 29, 2011)

You might find a used Unisaw motor on e bay for less. the VFD will be less than that. Brad can give you specific suggestions when he catches up with this thread.


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## MrUnix (May 18, 2012)

It will cost you about $200… what is the FLA listed on the motor?

Cheers,
Brad


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## runswithscissors (Nov 8, 2012)

Grizzly has a 3 hp motor with the Unisaw mount.


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## maverik (Dec 30, 2015)

Well here's a 3HP VFD single phase input 230V for $207. there are several more on this web site if you don't want this one. There is one that has a remote key pad you can mount where ever is convenient for $261.
http://dealerselectric.com/L510-203-H1-N.asp


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## KelleyCrafts (May 17, 2016)

There's this as well. I run a bigger one for the 7.5hp motor on my saw. This one is good for a 3hp motor. About $195 shipped.

https://www.amazon.com/gp/aw/d/B006ETPE7A/ref=mp_s_a_1_1?ie=UTF8&qid=1495580337&sr=8-1&pi=AC_SX236_SY340_QL65&keywords=phase+o+matic&dpPl=1&dpID=313Wt-IJLQL&ref=plSrch


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## SweetTea (Aug 5, 2016)

> Well here s a 3HP VFD single phase input 230V for $207. there are several more on this web site if you don t want this one. There is one that has a remote key pad you can mount where ever is convenient for $261.
> http://dealerselectric.com/L510-203-H1-N.asp
> 
> - Lee


So this would be fine to use on my 34-450 UniSaw? Just plug and play?


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## MrUnix (May 18, 2012)

> So this would be fine to use on my 34-450 UniSaw? Just plug and play?
> - SweetTea


The Teco L510-203 should work… but you might be able to use the L510-202 for $173 depending on your motors FLA. You could also go with a simpler V/hz drive like the FM50 for a little less money (the FM50-202 is about $156). How they get wired in depends on your saw and what is there now. The converter Ki7hy pointed to is a static phase converter that will reduce your motors output by about 1/3 and has a few other quirks.

Let us know what your motors FLA is. You should size based on current, not marketing hype 'horsepower' ratings.

Cheers,
Brad

PS: There are some cheap no-name imports on the bay - but based on reviews, they can be hit-or-miss… might last 10 years, might last a month.


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## SweetTea (Aug 5, 2016)

> So this would be fine to use on my 34-450 UniSaw? Just plug and play?
> - SweetTea
> 
> The Teco L510-203 should work… but you might be able to use the L510-202 for $173 depending on your motors FLA. You could also go with a simpler V/hz drive like the FM50 for a little less money (the FM50-202 is about $156). How they get wired in depends on your saw and what is there now. The converter Ki7hy pointed to is a static phase converter that will reduce your motors output by about 1/3 and has a few other quirks.
> ...


Ok, thank you for the info! I won't be able to pick it up until tomorrow. (It's a 2 hour drive but I already paid for it). I will check the motor plate. What info on the motor plate should I be looking at?


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## wapakfred (Jul 29, 2011)

There should be a box on the motor plate labeled "FLA", that number allows proper sizing of the VFD.


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## PhaseCraft (May 9, 2014)

Looks like I'm a few months late to this party, but here's some helpful information on table saws and phase converters: A table saw is one of the easiest machines to run on a static converter. The obvious advantages are they're cheap and easy. The tradeoff is, you'll lose 1/3 of your horsepower because you aren't really running your saw on 3-phase. All a static converter does is provide an artificial phase to get the motor running, using start capacitors. As soon as the motor starts, the static converter drops out of the circuit becoming a passive device, and all it does is allow the saw motor to continue running directly on single phase power. If you measure the voltage between the windings, it's all over the place because there are no run capacitors to balance it out. For long term use in an industrial setting, you're going to shorten the life of a fairly expensive motor.

I make static converters, but I'm not a big fan of them. I always tell my customers that they'll be much happier with a rotary converter that will give them true three phase power, and a well-balanced output. It really doesn't cost that much more. Our Phase-Craft model 10-HP-18 gives you true three phase power, and currently only costs $200, plus around $100-$150 for a used 10-HP 3-phase 1700-1800 RPM idler motor, which you can usually find pretty easily at a metal scrap yard or Craig's List.

A static converter only has start capacitors which start your 3-phase motor on single phase, and then drop out of the circuit. A rotary phase converter control panel will start your idler motor the same way, but when the start caps drop out of the circuit, it also has run capacitors that help to balance your output voltage. Output voltage balance is a moving target and is never perfect, but by matching our control panels to both the horsepower AND the RPM of your idler motor, we're able to get it pretty close… close enough to run CNC machinery if the panel is sized correctly for your machine.

Another advantage to a rotary phase converter, is they're virtually bulletproof. We've got converters out there that have been running in industrial settings for close to two decades with no problems. I've yet to hear of a VFD that can make that claim, plus a 10-HP rotary panel can usually run several different machines in a typical home workshop. We make control panels from 3-HP up to 25-HP, but the 10-HP panel definitely gives you the most bang for your buck. You can see most of our panels at a certain online auction site, but we also take direct orders over the phone, and I'm always happy to answer questions, whether you buy a converter from me or not.

Jim
(714) 710-9094


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