Can I run this 208v 3 phase grinder on 120v single phase?

[IntrstlarOvrdrve]

Sorry for the newb question, I picked this Wissota 3/4hp grinder up off of craigslist yesterday. It was right down the road from my work so I ran over during lunch but didn't realize until I got home last night that it is a 3 phase. I know that each phase is 120v to neutral on 208 3 phase, so would it be possible that I run it on a single phase?

 

[seber]

You could if you buy an inverter to supply the correct power. Hooking it up to 110vac would just burn it up.

 

[454ragtop]

Only way is with a 115 volt input VFD, a 3/4 HP one is probably about $125.
http://dealerselectric.com/FM50-101-C.asp

 

[marinusdees]

You can run it on 220-240 volt singe phase, if you rope start it.

 

[Taniawolf]

You can start 3 phase grinder on single phase supply. Check this video in which a user is running it: Youtube Video Link: 3 phase grinder running on single phase

Here is the circuit diagram of a three-phase motor running on single phase using additional capacitors:

I have a lot of experience with these motors and they are quite simple in technical hands. But I never come through grinder like this. Hopefully, its working goes same. Keep your safety a priority.

 

[Taniawolf]

Only way is with a 115 volt input VFD, a 3/4 HP one is probably about $125.
http://dealerselectric.com/FM50-101-C.asp

VFD is apparently the simplest way for the OP but it'll be more expensive than grinder itself.

 

[rsanter]

Only way is with a 115 volt input VFD, a 3/4 HP one is probably about $125.
http://dealerselectric.com/FM50-101-C.asp

Do this
You won’t regret it

 

[IntrstlarOvrdrve]

Thanks for the suggestions, I will look more into the capacitors and decide whether to try that or the VFD converter.

And yes, the converter is about 6x the cost of what I paid for the grinder itself (I gave a whole $20 bill on it and the stand).

 

[OccupantRJ]

The capacitor system is known as a static phase converter and will produce about 2/3 hp rating.

 

[blazemaster83]

Buy or build a rotary phase converter and start buying more 3 phase tools, you won't regret it.

 

[Mark in Indiana]

IntrstlarOvrdrve:

I've wired in a run capacitor on my 3 phase, 220V/440V, 1HP grinder. I run it on 220 V single phase. I found a YouTube video on how to do it. Second picture shows the test set-up. The wiring & capacitor are in a proper enclosure.

For me it's the best way to go, since I didn't want to put very much money into it. It cost me ~15$ for the capacitor, enclosure & hardware. Yes there is a 33% HP loss & it takes longer to get to top speed, but it's fine for my needs. I've also read that it's hard on the motor, but as much as I use it, it will outlast me.

My milling machine has a VFD, which is a perfect fit as far as a good conversion and speed control. I'll do the same thing if I end up with a 3 phase lathe or surface grinder.

If you don't mind my asking, how much did you get your grinder for?

 

[IntrstlarOvrdrve]

I paid $20 for the whole setup

And I would love a rotary phase converter, as I'd like to add a milling machine to my shop at some point..but neither of those things fit into my budget right now.

 

[marinusdees]

I paid $20 for the whole setup

And I would love a rotary phase converter, as I'd like to add a milling machine to my shop at some point..but neither of those things fit into my budget right now.

Then find a capacitor or two or three and generate a dummy third leg as described and run it. Check the voltage between each pair of legs with the motor running. It should be fairly equal. but this isn't like building a watch. Close is good enough. I run my three phase chain hoist with a set up with a couple of caps in parallel in a metal box. Ideally, the caps should drop out once the motor is running, but I just leave them in the circuit. The run time is always fairly short, so overheating is not a problem. And, yes, I have four machines running on VFDs, so I am aware of the benefits. Given your budget, this is a no-brainer.

 

[Mark in Indiana]

BTW: If you do the static phase method, make sure that you use motor run capacitors. Motor start capacitors are not made for continuous use and will explode.

 

[Taniawolf]

IntrstlarOvrdrve:

I've wired in a run capacitor on my 3 phase, 220V/440V, 1HP grinder. I run it on 220 V single phase. I found a YouTube video on how to do it. Second picture shows the test set-up. The wiring & capacitor are in a proper enclosure.

For me it's the best way to go, since I didn't want to put very much money into it.

Mark that's excellent work and real DIY. The pics are great, but it'll be even more useful for OP (and for my learning and for others as well) if you post one or wiring pics from a different angle.

 

[exmaxima1]

I have the same size Wissota in single phase. Pics are before & after some tlc.

Great grinders, and I hope you get yours running. And even if you don't, the stand and power switch are worth the $20 you invested.

 

[Augus7us]

You can find a VFD cheaper than 125$ but you'll have to dig, problem is I'm not sure how easy it is to find one that takes 110v. I know they make them, KBAC has them. But you will pay a lot more than 125$ from them!

If you can get a 220v drop you can find a used solid state converter like a phase o matic that should do. There is a new solid state converter on ebay from an off brand for 65, if you have 220.

I bought a pen lathe for 25 and got a phase o matic free with it a few years ago. I have it and a KBAC VFD powering tools in my shop. No complaints about either.

-Clint

 

[Mark in Indiana]

Mark that's excellent work and real DIY. The pics are great, but it'll be even more useful for OP (and for my learning and for others as well) if you post one or wiring pics from a different angle.

Taniawolf & All:

Although I don't have any more pictures of my pedestal grinder conversion, I found the YouTube video that I used to get the information on how to do it.

Here's some information on selecting the size of run capacitor needed for the motor per horsepower. Note: You have some wiggle room when choosing your capacitor. It doesn't need to be exact.
https://www.electricneutron.com/electric-motor/single-phase-capacitor-sizing/



Hope this helps out.

 

[seber]

How much does it cost to get the motor rewound for single phase? I have the same grinder in single phase. It is way better than my Craftsman block grinder of the same power and vintage.

 

[American Locomotive]

It would cost 2x what the grinder is worth clean retail to have a small motor like that rewound for single phase.

Just get the $120 120v to 200-240v 3-phase VFD.