Motor selection for belt grinder?

TXscout

TXscout

Joined
Jul 9, 2008
Messages
73
I just finished putting together my Grinder in a Box kit, that I ordered from Polar Bear Forge, and can't wait to slap a motor on it, and get started with some builds.

I’ve decided I want a 3450rpm, 2HP motor, and want to hook it up to a VFD for speed control. Can you use a VFD on a single phase motor, or does it have to be a 3 phase? I found a good deal on a 2hp, 56c, TEFC, 115/230v, single phase motor, but I cant figure out if this is what I need.

Any input is appreciated!

Thanks
 
For VFD use your going to need a 3 phase motor....if you hook up a single phase motor to a VFD, all you'll do is burn out the motor and the VFD. For a 2 hp motor, I would recommend the KBAC 27D VFD. This VFD also has an internal "jumper" that can be set for "standard" or "double" speed....meaning that you can use either a 1725 3450 rpm motor.... giving you more options.

I recently purchased a brand new 2hp/3phase TEFC motor off Ebay for $100.....brand new, still in the shrink wrap. If you take your time, you can find some great motor deals on ebay.
 
TXscout said:
I just finished putting together my Grinder in a Box kit, that I ordered from Polar Bear Forge, and can't wait to slap a motor on it, and get started with some builds.

Can you use a VFD on a single phase motor, or does it have to be a 3 phase?
Click to expand...

No you cannot use a VFD on a single phase motor.

It must be three phase.
Also be sure it is a 220 ish volt motor.
(220 -230 whatever)
There are 440v and 575 volt motors that you can't use

If you check Ebay-Craigslist-kijiji-whatever you can find some real deals on used motors

- and since you are in the States shipping charges can be reasonable.
 
Thanks guys--I just needed some confirmation that I should be looking for a 208-230/460V, three phase unit, in order to run with a VFD. Actually, those will be easier to find.

Having struggled with my little, Delta 1x42" grinder, build after build, this is going to be a nice setup for me.
 
If you need a 3 phase for a Freq drive, why does Travis sell his TW90 with a single phase and Freq drive? I'm confused?
 
Mooseyard said:
If you need a 3 phase for a Freq drive, why does Travis sell his TW90 with a single phase and Freq drive? I'm confused?
Click to expand...

You mean this ?

http://www.twuertz.com/Product_Specs.html

"Drive: Comes standard (only) with 2 horsepower Variable speed (via variable frequency drive).
Power output is 2hp on 220 single phase and 1 ½ hp when run with 110 single phase power"




It is poorly written.

The motor must be 3 phase to use with a VFD

The statements above refer to the power input from the electrical supply to the VFD

not the output from the VFD to the motor.

A KBAC-27D is rated for:
1.5 HP with 110 VAC single phase input
2 HP with 220 VAC single phase input


The statement above sounds like he ships with a 2 hp motor even if you intend to use on 110vac
Maybe that works, I've never tried that.
 
Ok, that makes some sense. The input to the freq is single phase and output from the freq to the motor is 3-phase.
 
Can a J56C motor, or a 56C, with a threaded 5/8" shaft, be used? I found a Leeson Washdown, locally, that is brand new. I just wasn't sure if it could be utilized with a threaded shaft.

Thanks!
 
I think so yes- the shaft is longer, the threaded end is added on as extra length.


When you see it in person, be sure it has a keyway.

You can use other means of driving the wheel, but it is most simple if you can use it as is.
 
My bad on wording. I figured all that really mattered was the input power source since I wire and test everything before I send it out.
 
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