3 ph to 1 ph conversion question

[Bill Blackburn]

Bought a truly mint early '60's Uni today - looks to be nearly spotless even inside. Issue is the 3 ph motor of course - so what would the starting point in the decision making process be - look at a convertor and the cost of a new motor and decide from there or ????
I have no clue where nor how to begin this process but this saw was so sweet and so cheap at $200 I could not pass it up. It was fenceless but I have a spare unifence so that was solved. The motor is the hangup.

Has anyone else done a conversion? Rough $$ figure to do so if you would share would help me out. I can start the motor search today too.
This little devil has me mighty exicted I admit - always wanted one like this.

Thanks for any and all help.

Bill

[Faust M. Ruggiero]

Bill,
If you have no intentions of buying any more three phase machines, I would find a single phase 220 volt motor. The phase converter will coat at least as much and will require a bit of wiring.
fmr

[Jamie Buxton]

SMC's Search function will bring you about three zillion threads about making 3-phase from single phase.

[Rick Christopherson]

If the cost were the same or even slightly higher, between the choice of replacing the motor versus adding a VFD, I would choose the VFD. On the other hand, given the same choices between swapping the motor and adding a phase converter, I would swap the motor.

[Rollie Meyers]

I used this firm for a 3 HP 1Ø unisaw motor, 3 HP will do fine on a 20A 240V circuit.

http://www.electricmotorsite.com/pc/..._unisaw/120728


For a VFD research check these sites.

http://www.automationdirect.com/adc/...alog/AC_Drives

http://dealerselectric.com/mfg-subca...cID=165&mID=-1

http://www.factorymation.com/s.nl;js...=2&category=11

You will still need a enclosure for your drive & the size can be large enough to break the bank, download a manual & read manufacturers instructions...

[David Christopher]

grizzly sells motors that will fit.......direct bolt on

[Rollie Meyers]

grizzly sells motors that will fit.......direct bolt on

But all Grizzly is: Cheap Chinese Junk. Best to avoid Chinese or Taiwanese Electrical parts.........

[Ben Martin]

Teco FM50 VFD from FactoryMation, should be about $140-50 shipped.

[Rick Christopherson]

You will still need a enclosure for your drive & the size can be large enough to break the bank, download a manual & read manufacturers instructions...

You are misreading the manufacturer's data. There is nothing mandating an enclosure, only that if you use an enclosure that it be of sufficient size to provide proper air circulation.

[Rollie Meyers]

You are misreading the manufacturer's data. There is nothing mandating an enclosure, only that if you use an enclosure that it be of sufficient size to provide proper air circulation.

I disagree, unless the drive has a NEMA 1 accessory kit like a GE/Fuji models have avail. it's a jury rigged install for strain relief of the conductors.

[Thomas Syrotchen]

Bill,
There are a few other pieces to the cost equation you want to consider. If you replace the motor, there is a lot less to break than when you add a VFD or phase converter. Ten years ago I built a rotary phase converter because it was the cheapest solution. I've had to replace a couple of parts and I'm now at a break even point. If I had to do it over again, I'd convert the motor to single phase and be done with it. The other piece I never took into account, every piece of equipment you add will result in an increase in your electric bill. It may be negligible depending on the technology. In my case, once I added that in, it would have been a lot cheaper to replace the motor and be done with it. Resale value is the last piece I'd consider. I'm really kicking myself now, because that put me deeper in the hole. I look back now I see I could have had a nice old cabinet saw, built like a tank, with a brand new motor, or three phase power for an old motor which sounds like the beter choice?

[Scott Holmes]

I have a 3 phase planer, I purchased a phase converter for ~$100 10 years ago.

Never been a problem, easy to wire.

The 3 ph motors don't have start capacitors so the phase conv "jump starts the motor once it's running the 240 single phase is fine. You do lose a little power but I have never been able to even slow that 5 hp motor.

[Dick Strauss]

Thomas makes a very good point about resale value should it ever come to that.

[Chip Lindley]

$200 for a nice Unisaw is Wayy Cheap! You got the bargain because nobody else wanted to deal with the 3-phase motor issue--a sore point to some--serious fear factor to many more!

Now is up to you to choose your weapon of choice to end up with a single-phase saw you can use! (1) Pony up for a 1-ph motor if resale value is an issue. (2) Remember that each 3-ph machine will have to have it's own specific VFD. (3) If you plan on future 3-phase bargains in your shop, a rotary phase converter is the real way to go! ...IMO

[Rick Lizek]

I have a 3 phase planer, I purchased a phase converter for ~$100 10 years ago.

Never been a problem, easy to wire.

The 3 ph motors don't have start capacitors so the phase conv "jump starts the motor once it's running the 240 single phase is fine. You do lose a little power but I have never been able to even slow that 5 hp motor.

Not enough info on your converter. A static will lose approxa 1/3 hp but a rotary will deliver full power as will a VFD or Phaseperfect. I would say you bought a static converter from your description of "jump start" as that's basically what a static converter does. It creates the third leg to start the motot then drops out so you are running on 220 single phase. The momentum keeps the motor running past the missing leg, hence the 1/3 loss of power. On certain machines a hobby woodworker wouldn't ever notice the difference on the right application. An example would be a 5 HP table saw. A static would make it comparable to a 3 HP which is enough enough for most commercial shops. I'm sure Rick C will chime in about balanced static converters...