2X72 motor will this work?

[Jarrod Risley]

I have been toying with the idea of building a 2x72 belt grinder for a while now. Finally ready to start sourcing some parts to bring it together. Trying to stay cheap as possible for the build and I got a lead on this motor. It is a 2hp 3ph motor with a G56C frame. I have attached a photo of the nameplate. I was curious if some of the more experienced guys on here could weigh in and list any reason as to whether or not this is what I need. I plan on using a VFD (single to three phase) and just don’t want to drop coin on a motor just so I can let the magic smoke out of it if I miss something. After all I’m a welder by trade, not an electrician. Lol

Note: this is my first post. I hope I get the photo in right.

https://www.flickr.com/gp/162221671@N04/P2Hut7

 

[A.McPherson]

Looks like it should work... I’m no expert, but it looks like it’s totally enclosed and rated for continuous use. You should be good to go.

I’m sure one of the more experienced guys will cond and correct me if I’m wrong...

 

[Ken H>]

The only thing you need to check is if it's TEFC or not. I'm not sure if "all 56C frames are TEFC or not. "IF" you're getting it for almost free, then using it until it does go bad from metal dust won't hurt anything, but another 56C motor will bolt right up for <$200 new.

 

[cotdt]

I wonder if anyone ever tried to power a belt grinder with gas-powered engines. There is much more power available in those.

 

[Jarrod Risley]

The only thing you need to check is if it's TEFC or not. I'm not sure if "all 56C frames are TEFC or not. "IF" you're getting it for almost free, then using it until it does go bad from metal dust won't hurt anything, but another 56C motor will bolt right up for <$200 new.

I was thinking that too. It does say TE on the info plate so it’s totally enclosed, but it is not followed by FC. so would this be a motor without a fan? And if so is that a deal breaker? It is also rated for continuous use.

 

[A.McPherson]

I looked into using a 15 hp gas engine to run a grinder. For the size, weight, torque and most of all expense of operation, electric is the way to go!

 

[Ken H>]

Can you get a photo of the whole motor? Is it one of those "super cheap" deals? Remember, 3 ph motors are available for <$200 shipped, and a 3400 rpm is $158 shipped. Ooops, I see the 2hp 1750 rpm has increased to $214 shipped now.

 

[Stacy E. Apelt - Bladesmith]

TEFC cooling is nice to have, but for the short length times we run a grinder a TE is sufficient. There is usually an internal thermal breaker that will shutdown the motor if overheated.

If you really worry about it, put a small pancake fan ( surplus computer fan) about an inch behind the motor. That will actually be better than a TEFC motor, as the fan on TEFC is only efficient at near full speed. As you lower the RPMs, the cooling drops by the square of the speed drop - at half speed, it is only 1/4 efficient at cooling.

BTW, TEFC fans need to be blown out and vacuum regularly. The dust and steel from running a grinder can clog them badly.

 

[Jarrod Risley]

TEFC cooling is nice to have, but for the short length times we run a grinder a TE is sufficient. There is usually an internal thermal breaker that will shutdown the motor if overheated.

If you really worry about it, put a small pancake fan ( surplus computer fan) about an inch behind the motor. That will actually be better than a TEFC motor, as the fan on TEFC is only efficient at near full speed. As you lower the RPMs, the cooling drops by the square of the speed drop - at half speed, it is only 1/4 efficient at cooling.

BTW, TEFC fans need to be blown out and vacuum regularly. The dust and steel from running a grinder can clog them badly.

Good info. Thank you.

 

[cotdt]

I looked into using a 15 hp gas engine to run a grinder. For the size, weight, torque and most of all expense of operation, electric is the way to go!

But think of how fast you would be able to profile blade blanks. I've seen some used car engines for only $100.

 

[A.McPherson]

But think of how fast you would be able to profile blade blanks. I've seen some used car engines for only $100.

Lol! I can only think of how fast I would ruin knives...
Although I have thought of setting up one of those old timey machine shops with the overhead drive shaft and the leather belts and such. Just super cool, not cost effective.