View Full Version : KBAC Hybrid AC Drive... anyone use one before?

12-28-2014, 10:40 AM
So, just this last September I picked up this Teco VFD & motor combo for my still apart-in-a-million-pieces knee mill:

1 HP, 1800 RPM, Brook Motor with 1 HP, 115 Volts, Teco VFD
Item#: 1 HP 1800 RPM 115 Volts Input Package

Doing homework on installing the VFD into an enclosure, adding all the other do-dads and wires required, I ran into this interesting thread about the KBAC-24DGR here (http://www.practicalmachinist.com/vb/transformers-phase-converters-vfd/new-teco-vfd-install-enclosure-3-ph-motor-226569/index2.html#post2299254). Found a little more info and a couple vids here:

KB Electronics KBAC-24DGR

KBAC Hybrid AC Drive

KB Electronics KBAC Series AC Drives

Looks very interesting to me, and seems that it be much simpler/easier for the novice like myself to hookup and deploy. Not to mention nice, tidy, sealed box out of the shute... anyone here have experience running one of these? Pretty curious...

12-28-2014, 11:51 AM
Interesting. It is probably not quite as efficient as more sophisticated drives, but that may not really be necessary. In the video, I noticed that the motor was connected using the green ground wire for one of the phases. That is probably against code, although you could add another external ground.

12-28-2014, 01:34 PM
, I noticed that the motor was connected using the green ground wire for one of the phases. That is probably against code, although you could add another external ground.

They were probably lazy in not using 4 core cable, it is OK in the code as long as the correct colour is used to identify the conductor at all termination points by coloured tape etc.

12-28-2014, 01:58 PM
NEC code changed on that matter some time ago.. Now you either run a bare wire, a green wire ,or you tape it the entire length (lol).

Mike Amick
12-28-2014, 02:49 PM
Hooking up a box with some switches and a potentiometer is pretty easy when you work with
that stuff. But I have to admit, If you have never done it and have the bucks, those ready
made enclosures are REaallly nice.

There are a lot of posts from guys thinking of going to 3ph VFD and if you are a little
ETH (electrically technically handicapped ) .. its kind of scarry.

But .. the moment you do it, you wonder what the worry was all about. You basically
plug the VFD in. Take the three wires from the motor and hook them up to the three
motor terminals. It doesn't matter what colors you put where, you can't hook them up
wrong !

Then, its just a matter of letting the VFD know about the motor you have it hooked up too.

You have to do that either way. Ready made or home made.

On home made boxes, you just look in the manual and it will tell you what two terminals
to hook a switch too .. to make a start switch. And what 3 terminals to hook a
potentiometer up too to make a speed control .. etc etc .. its that easy.

But yea .. if you got the buck and would rather not deal with all that ... those boxes
are a beautiful alternative.

Mike A

12-28-2014, 03:26 PM
I've used KB dc drives for a really long time, about 20 years now and they are a very good drive. I find that 'easy' programmable drives aren't, and that their so called hybrid with pots for setup are great when 10 years down the road you need to make a small change. I even used one of their 4 quadrant drives to reel in a large hose over several hundred feet. I set the torque limit to provide the tension I wanted, and the speed to full. The reel stalls at current limit as you feed the hose back on the reel spins at whatever speed is required to keep the tension constant. I wouldn't hesitate to buy any of their products.

12-29-2014, 10:45 AM
Thanks guys. I'm not too afraid of hooking up the Teco, lots of monkey see monkey do installs on the web. It's just, really liked the idea of a small compact control box you could mount on a swing arm, and... 10 minute install time looked pretty peachy too.

Plus, I have a KBMD-240D driving a 3/4hp Baldor DC motor on the lathe which has always run flawlessly. I trust KB, just not sure I want to pony up atm... :)