Electric motor and VFD questions.

[Randydb]

Me being a cheapskate I went with a chinese VFD for $120 shipped, but it's an open frame rather than NEMA 4X dust proof. For full time 10/day, 5 day/wk use I'd go with a NEMA 4X enclosure for VFD, but for my hobby work I put air filter over inlets and have VFD mounted to back & one side of grinder and dust hasn't been a problem. OR - mount in a dust proof box.

Later

I watch how dust gets into everything in my garage and I wonder if it isn't just a matter of time before something gets in there and it goes wrong. Although at $120 you could buy 3 of them for the price of 1 that is sealed. I woud be interested in seeing a picture of what you have done. I'm so cheap!

 

[Howard1]

To run a variable speed VFD set-up you will need a 3-phase motor. 3-phase motors only come in 220 volt. Many VFDs will allow you to run a 3 phase motor using either 110 or 220 volt. The KBAC 27 D will run a 2 HP motor on 110 Volt but you will only get 1.5 HP. If you can run 220 to the VFD you will be able to get a full 2 HP from the motor. You will want a 1750 motor instead of 3450. The VFD will allow you to run the motor at 2x speed. My KBAC 24D that I have on my disc grinder runs a 1HP motor off of 110v power. It works great.

So you do not NEED 220v in the shop, but you will need the correct VFD and a 3 Phase 220v motor. This is a link to the 27D drive.
http://www.electricmotorwholesale.com/9520-KBAC-27D/

I am running a 1725 RPM motor with a VFD. The manufacturer of the VFD, TECO Westinghouse, said that if i set up the VFD to run the motor at 3500 RPM it will burn out the motor. He offered to help me set it 20% ahead but no more. Any insight as to why your post is so at odds with TECO?

 

[Randydb]

I am running a 1725 RPM motor with a VFD. The manufacturer of the VFD, TECO Westinghouse, said that if i set up the VFD to run the motor at 3500 RPM it will burn out the motor. He offered to help me set it 20% ahead but no more. Any insight as to why your post is so at odds with TECO?

From the threads I have read over the last year it seems like running a 1725rpm motor double to 3500rpm is common. Maybe I am wrong. I'd like to hear from some of the old timers here.

 

[Josh Rider]

I'm not an old timer just yet, but I run my Teco at 120hz which doubles my 1750 rpm motor going on 3 years.