Which motor-TEFC or TENV?

[Sticks]

I'm building a "grinder in the box" and have been very pleased with the kit. But now I need to buy a motor. The kit requires a 56C frame motor. I want variable speed and likely will buy the KBAC 27D VFD (mostly because that's what my friend has on his KMG and VFD's confuse the heck out of me.)
So back to the motor. I want 2hp and will have 220v 60 hz single phase current.

This will be a direct drive grinder and I've read postings that I should use a motor that runs at 3450 rpm or so. The grinders I've seen pictured use a TEFC housing. There is a big price difference between TEFC and TENV housing, the latter being much less expensive. What are your thoughts on using the TENV housing? I understand that the TENV (having no fan) will run hotter, but would grinding for 30 mins. or so cause it to overheat?

 

[Wayne Coe]

If you are going with a VFD you must have a 3 phase motor but the VFD is the phase converter so you can run it on your single phase 220 or probably 110.
TEFC is Totaly Enclosed Fan Cooled. Totaly Enclosed means that the grinder dust does not get into the motor and short it out.
I can ship you a 3 ph 2 hp TEFC motor for under $200.00.
How big a hurry are you in? I am leaving Friday for 3 weeks, visiting Dogs, doing a Build a Belt Grinder Workshop and teaching a Beginner's Blacksmithing Class at the New England School of Metalwork.
I will have my computer with me and will be able to receive PMs and will be able to get the motor shipped to you, if you want it. You can pay for it by PayPal.

 

[silver_pilate]

For a 2hp motor, you'll need 220V single phase input. As Wayne stated, the VFD converts that input into 3 phase to the motor. You'll need a 3 phase motor. I have TEFC's running on my 2x72" grinders because of the load they have placed on them. Also, 30 minutes may sound reasonable, but you'll find yourself running them much longer than that. I have a 3/4 hp TENV motor running my disc grinder. It doesn't face near the load (for my style of grinding), and it is run for shorter periods of time.

--nathan

 

[Sticks]

Thanks for the info Wayne and Nathan. Wayne, I'm on a slow track, but your price is reasonable. Nathan, I think you're right about 30 mins. being too short a run time. One of the great things about grinding is that the time flys by. Half an hour is gone before you know it and I grind slowly anyway.

I asked the question because I read in another forum that TEFC motors are overkill for the average home shop. And that would make sense for something like a table saw. But grinders typically run much longer.