# Convert Single Phase To 3 Phase



## plasticracer (Feb 3, 2016)

I purchased a Harrison m300 lathe that uses 220  3 phase power and I have 220 single phase in my shop...What is the most efficient method of supplying power....some type of inverter or should I buy a new motor  thanks in advance
Wayne


----------



## ELHEAD (Feb 3, 2016)

I put an inverter on a 5 HP 3 phase motor for my Stephan Bader 132" sander. Inverter was US made of choice imported and domestic components. Works great.


----------



## Eddyde (Feb 3, 2016)

In my opinion a Variable Frequency Drive "VFD" Is the best way to go. It will not only convert single to three phase but also allow you to vary the motors speed, electronic breaking, overload protection and other features. They are a little more complex to set up but you will find plenty of help here.


----------



## Cheeseking (Feb 3, 2016)

Thats a beautiful lathe I wouldn't compromise it with single phase.  Get a VFD or RPC.


----------



## plasticracer (Feb 3, 2016)

thanks  ..............any particular brand of vfd I should look for
Wayne


----------



## Eddyde (Feb 3, 2016)

I bought a Teco L510 for my mill. I was pleased with it so I bought three more for other machines.
The VFD works much better than the static phase converter, I had on my lathe. Static converters downgrade the motors rated horsepower by a third.


----------



## Slackerzinc (Feb 3, 2016)

I bought a teco n5 VFD and after looking at the quick start guide(5mins) I had it hooked up and running


----------



## Ed ke6bnl (Feb 3, 2016)

I still like the home made rpc rotary phase converter, I can use it on more then one Item. my mill and my large drill press just my thoughts.


----------



## plasticracer (Feb 3, 2016)

thanks everyone for the input...


----------



## gmhill33 (Feb 3, 2016)

Can a VFD be used on a standard 110 drill press or does it have to be 220?

Thanks,
Gary


----------



## JimDawson (Feb 3, 2016)

gmhill33 said:


> Can a VFD be used on a standard 110 drill press or does it have to be 220?
> 
> Thanks,
> Gary



In general, no  A single phase motor can not be used with a VFD.  VFDs can only be used with a 3 phase motor.  Now if your drill press is powered by a 110V, 3 phase motor, then yes it could be done.  About the only place you will find 110V 3 phase motors is on aircraft.


----------



## gmhill33 (Feb 3, 2016)

Thanks for the reply. No it is not a 110 3 phase.

Gary


----------



## f350ca (Feb 3, 2016)

Jim, just thinking out loud, but why couldn't you run a single phase motor off two leads of the VFD. The VFD might not like the unbalanced load, but a single phase motor works here and Europe on 50 and 60 hertz.

Greg


----------



## JimDawson (Feb 3, 2016)

Theoretically you could do that.  As you stated, the VFD would not like it.  You could run a single phase motor on variable frequency, but you also have the centrifugal switch to deal with.  Single phase VFDs do exist, but as far as I can tell only in the very low HP ranges and only for split-capacitor and shaded pole motors.  I don't think they work with standard capacitor start motors.   Doesn't seem very practical to me.

http://www.invertekdrives.com/variable-speed-drives/optidrive-e2-single-phase/


----------



## f350ca (Feb 3, 2016)

Wasn't thinking practical Jim, just wondering if it could be done, but your right would be over a limited range or the centrifugal switch would come into play
Thanks
Greg


----------



## John Hasler (Feb 3, 2016)

f350ca said:


> Jim, just thinking out loud, but why couldn't you run a single phase motor off two leads of the VFD. The VFD might not like the unbalanced load, but a single phase motor works here and Europe on 50 and 60 hertz.
> 
> Greg


Yes, but it would only work over a narrow speed range with a capacitor-run motor and the starter circuit would cut in when you tried to slow down a capacitor-start motor.  As Jim notes there are single-phase VFDs but they are for restricted applications.


----------



## NCjeeper (Feb 3, 2016)

I went with American rotary for my 3 phase for my mill. They were top notch.


----------



## plasticracer (Feb 4, 2016)

Will the vfd work on a 575 volt as well or only on 230 volt?
Wayne


----------



## John Hasler (Feb 4, 2016)

plasticracer said:


> Will the vfd work on a 575 volt as well or only on 230 volt?
> Wayne


A VFD must be designed for a particular voltage.  575 volt VFDs probably exist but would be expensive.   Are you in Canada?  A 575 volt motor will run at reduced output on 480.


----------



## plasticracer (Feb 4, 2016)

yes I am in Canada....I was told it was 220 volt but when I checked last night it was 575....I guess I should have checked before I posted so my best option now would be to go with a 230 volt single phase motor ....thanks
Wayne


----------



## f350ca (Feb 4, 2016)

220 to 575 volt transformers are available Wayne. It may be getting expensive by the time you get a VFD and the transformer though. One thing you'll need to check is the transformer for the relays in the lathe. It may or may not have taps for 220.

Greg


----------



## Smithdoor (Feb 4, 2016)

It simple to build a rotary phase converter if you are do it your self person
It no more than three phase motor use to generator for the third leg
The ease way to build one is use three phase motor (Star would not delta wound) and smaller single phase motor to start the larger three phase motor note both motor must be the same RPM (Do not use belt drive)
Now just hook your input power to the three phase motor to T1 and T2 The T3 is use for your third leg of the three phase power.
Note rule of thumb is for the motors is 1 (start motor) to 5 (3 phase motor / leg generator)
Use a 1725 / 4 pole motor a 3450 / 2 pole has a lot of back ground nose Found this out after making the first one after about week change to 1725 motor use this one for 40 years till ever thing was sold.

Other detail at http://www.homemodelenginemachinist....-2012-273.html
Also at one time I upload on this data on this site


Dave


----------

