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View Full Version : VFD confused, and dumb, gettin dumber



JEP
10-22-2007, 10:45 PM
OK,
im thinkin of gettin birmingham 9x49, a 3hp, 3ph, mill, 16 speed,

1-does the 16 speed mean its a 2-speed motor??
2-will a VDF-L200-007NFU hook-up, and work??
3-what else do i need besides the VDF unit, from the motor-to-the 220V
outlet on my wall, or from the VDF-to-the motor??

im very electricaly challenged,,,aka,,dumber than dumb,
ive been going through the archives,,and im just getting confuded even more,

any help would be welcome,
im getting frustrated enough to just buy a grizzly,G9901,220V and be done with it,

jp

torker
10-22-2007, 11:59 PM
Jep...Hang in there with the VFD idea. You won't be sorry.
I put one on my ol' Universal mill. I love it. The VFD has so many features...I still don't know how to get many of them to work but the bottom line is...the thing wasn't all that hard to wire up. Standard 220V 1ph from the box to the VFD then regular three phase wiring to the motr through the VFD.
The instruction manual for my Lentze VFD made it easy enough that even I could wire it, with some extra help from the board members here.
Russ

Bill Pace
10-23-2007, 01:13 AM
I LOVE my VFD!! I think you will also. Do you follow the PM site (Practical Machinist)?, if not go there and scroll down to the section "transformers, phase converters & VFD's" and put "VFD" in the search mode and spend about an hour or so soaking up some good threads on the topic. Thats the way I got myself somewhat familiar with it before I jumped off and attempted an install.....

http://bbs.homeshopmachinist.net/showthread.php?t=22841

This thread with a pix of the VFD after I had got the VFD and some other personal features finished on my new ENCO.....

http://bbs.homeshopmachinist.net/showthread.php?t=22841

Like Torker said, it aint too bad a job to rig one up.

lenord
10-23-2007, 01:18 AM
John,

If the AC drive you specified is : http://www.driveswarehouse.com/c-149-drives.aspx?categories_id=149&ManID=10

That one is rated for 1hp. You need one rated for 3hp. If you plan on using the 3hp, 3ph, motor that is on the mill.

Generally, the 16 speeds are from a single speed motor for newer mills. I've only read about some lathes having a 2 speed motor...

Not having one, but drooled for a long time, all you need is a 3 ph motor and the correct VFD. Some wire to the outlet and a plug maybe...

Lenord

Mark Hockett
10-23-2007, 01:31 AM
Lenord,
My 16 speed Birmingham mill has a two speed motor but it is a 1986 vintage. I can't believe its over twenty years old now.

JEP
10-23-2007, 05:52 AM
Lenord,
its a 8 speed with a 220V motor,,belted,
and a 16 speed with the 3phase,
so in my mind its a two speed motor, its shure not in the belts/pullys,
i read that the VFD wont work with two-speed motors,

jp


John,

If the AC drive you specified is : http://www.driveswarehouse.com/c-149-drives.aspx?categories_id=149&ManID=10

That one is rated for 1hp. You need one rated for 3hp. If you plan on using the 3hp, 3ph, motor that is on the mill.

Generally, the 16 speeds are from a single speed motor for newer mills. I've only read about some lathes having a 2 speed motor...

Not having one, but drooled for a long time, all you need is a 3 ph motor and the correct VFD. Some wire to the outlet and a plug maybe...

Lenord

Bill Pace
10-23-2007, 08:02 AM
i read that the VFD wont work with two-speed motors,
jp

My Enco IS a 2 speed, and, while it WILL work on the high side, its picky about the way its fed. Have to slowly ramp up the potentiometer, and again slowly ramp down the speed or it'll go into default code. I looked up the code and changed the parameters with no difference (sorry, dont remember what they were, ---amp load??) Its pretty forgiving on other mis-cues ... bogging it down on a heavy cut, forgetting the brake is on (oops!) and yet is pretty finicky on the second speed issue.

I rarely use the high speed side, but if a person knew that they would use the higher speeds often it would probably be beneficial to research out all the ramifications.

mayfieldtm
10-23-2007, 09:46 AM
My Kent 14x40 has a 2 speed 3 phase motor and works absolutely great on both Hi and Low speeds with a VFD.

Just remember not to switch it while power is On.
It is recommended, Not to switch any VFD Load while power is applied.

You might consider using a "Reactor" on the Output side of your VFD, they help with this problem, plus protects against short circuits, and the Motor will run cooler by cleaning up the Motor Current Waveform.
Expect to pay around $150 for one.

A breaking resistor is a nice add-on if you like the Lathe to stop quickly.
You can actually program the deceleration rate.
These can easily be home made to save some $$$.

Fuses on the Input side of the VFD is highly recommended, and may be required in some areas.

Your Motor may not be designed to run at very low speeds for extended times. It can overheat because the internal fans can't keep it cool.
However, I've done this for long periods and not had a problem.
There are Inverter Rated Motors available if I ever cook this one.
Some people, use an external fan on their motor.

I would highly recommend a VFD, and well worth effort to wire one in.
One of the many nice things about VFDs compared to other type speed controls, is that they maintain most of the torque when running at lower speeds.

Automation Directs' catalog has some good information about VFD's and Accessories. ( not affiliated )

Tom M.