KBAC 27D and 29D VFDs

[Mike Heidrick]

I started running a KBAC 27D VFD on a 10" Baldor grinder and 10" buffer setup I built recently. This KBAC-27D VFD will power up to 1.5hp 220V 3ph motors on 120V in, and will power a 2hp 220V 3ph motor on 220V in. the KBAC-29D will power 3hp 220V 3ph motor on 220V in only (no 120V option on it). These VFDs are completely sealed Nema 4x IP65 rated setups and do not require the enclosures like many cheaper VFDs do that have cooling requirements and fans. They are not cheap though - about $360 for the 27D and $380 for the 29D. Its also a VERY SIMPLE VFD to use. All settings are made with jumpers inside the door - no programming or looking up codes. It comes with one switch for start stop (not AC line off), and the potentiometer. You can wire in AC line on/Off, fwd/stop/reverse, and a start jog switch as options. I wired in fwd/stop/reverse and also the AC line on/off. I used my own cheaper DPST and DPDT switches and not their expensive options. They are just toggle switches. Anyway check out these VFDs if you want simple sealed setups without a lot of hassle.


https://i.ytimg.com/vi/mxij7nDwX_E/hqdefault.jpg


Here is info on the VFDs from KBAC:


http://acim.nidec.com/drives/kbelectronics/products/ac-drives/ac-drives-nema-4


Here is a video of my grinder buffer setup:


https://youtu.be/T0fkYirFlb8

[Matt Day]

This sounds like an ad Mike, but I’m guessing you just really like them and want to share.

Tell me more about the switch you have to go from grinder to buffer. How many machines can me hooked up to the VFD at once? Love that buffer by the way.

[Andrew Hughes]

I don’t know how your guys running vfds tolerate the high pitch noise they make. I have a 10 hp Kay rpc and I can’t hear it at all. It sits just outside the wall of my shop quite as a mouse.
I also like your grinder and buffer setup Mike very nice.

[Matt Day]

Maybe I’m just old (turning 40 soon) but I don’t hear anything from my Teco vfd’s when my machines are on. My quietest machines are my 20” disc and grinder/buffer and don’t hear a thing from the vfd except on startup.

[Tom M King]

Thanks Mike. This is useful information. The wet grinder I want is not made, and I plan to make one with a Baldor buffer. These are just the VFD's I've wanted, but haven't spent any time looking for.

What high pitched noise? That frequency must have been gone for a good while now.

[Dave Cav]

I have six TECO vfds normally on all the time, and I don't hear any high pitched noises (at least from the VFDs) even with my hearing aids. On the other hand, my drill press has a GS1 from Automation Direct. It has a fan that's on all the time and it annoys the hell out of me. I only switch the VFD on when using the DP, then turn it off as soon as I'm finished. The only reason I got it was it has the speed control pot built in for about the same price as the TECO drives without the pot, but after living with it for a while I wish I'd spent the extra money and bought an upgraded TECO. The TECO drives generally stay energized 24/7 except for my mortiser and tenonner, which don't get used every day.

[Tom Bender]

Yeah my Teco is silent.

A couple of cautions with VFDs;

You only get so much speed reduction, maybe 30% so a 3600 rpm motor only runs at 1100 rpm and above.

A VFD can run your motor at more than rated speed causing it to self destruct.

Your motor will seem kinda wimpy since it has torque equal to or less than normal so it looses horsepower (rpm x torque)

And VFD rated motors are recommended.

[Dave Cav]

Another point to consider- if you run your motor at a reduced speed for any length of time you may have a problem with it overheating as the motor cooling fan won't be moving as much air.

[Dan Friedrichs]

That's cool - I didn't know anyone made an "enclosed" VFD.

Andrew, some of the newer VFDs have provisions to eliminate audible high-frequency noise (ie they'll intentionally introduce some electrical noise to add distortion).

[Andrew Hughes]

That's cool - I didn't know anyone made an "enclosed" VFD.

Andrew, some of the newer VFDs have provisions to eliminate audible high-frequency noise (ie they'll intentionally introduce some electrical noise to add distortion).

Ok gotcha, I’ve heard Vfds in person and videos that make that buzzing noise. It reminds me of the dentist office.
If others report no noise I believe them.
For myself Kay Rpc till the end.
Good Luck Everyone