GFCI friendly VFD?

PIndelicato

PIndelicato

Joined
Sep 16, 2002
Messages
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Does anyone know of a VFD that plays nice with GFCI circuits? I learned the hard way that the KBAC on my KMG does not, and it's been a thorn in my side ever since. Just wondering if there are any other viable options out there.
 
Well afaik they make a gfci compatible one, but the easiest option would probably be to run a standard circuit to where your grinder sits.


Here's a link to the 27d gfci model: http://www.electricmotorwholesale.com/9667-KBAC-27D-GFCI/

I only made the mistake of running one of my vfd's off a gfci recept once, and got a nasty shock when I touched the wrong something else.. Good luck, don't zap yourself! ;P
 
Change the breaker or run a dedicated non-GFI circuit. Pretty much anything that causes fluctuations or ripples in the line will trip a GFI. I tried to put a plug-in intercom to the grinding shop, but it tripped the GFI because the AM superimposed on the voltage reads as a voltage differential.
 
I read something about this, but don't have GFI outlets here myself.

I forget the details, but changing the position of the GFI outlet either upstream, or downstream in the circuit made the difference.
(I think it was upstream)


I would contact the KB electronics tech service for info
 
Yeah actually on second glance, that VFD I posted has built in GFI protection, no idea if that makes it compatible, but I do recall reading in the KBAC manual that there were vfd's available for use on those circuits.. Are you forced to use outdoor recepts for your grinder, or are you grinding in the bathtub? ;)

I'm guessing you're in a garage and all the circuits there are gfci cause they run outdoor recepts also.. You may not want to switch those breakers, so your best option may be to run a dedicated circuit.. While having it done, I'd go ahead and run a 220 circuit, switch the VFD to 220 input, and then you've got a circuit to run some heavier tools off of later, like a welder, etc..
 
javand, I saw that one but it also sounds to me like it has GFI protection built in vs. being compatible. The manual does state that there is 'special software' available for GFI use, but I got nowhere trying to find out about obtaining it.

I am in a garage, and local code requires GFCI. I do not want to modify the existing circuits, and having dedicated lines is expensive and only works until you decide you want to move the grinder to a different location or want to plug something else into it instead.

I didn't really think there was an option out there, but thought it was worth a shot. I know a couple of years ago folks were using Teco drives, for example, but I have no experience with them or any other brands.
 
Well, as suggested, I'd *strongly* recommend you call KB Electronics, they're usually very helpful on the phone. I'm sure they can either offer a solution, or some closure, either way, make the call. ;)
 
I tried that when the issue first arose, and they did not seem interested in helping me at that time.

If you have a helpful contact there, please let me know and I will try again.
 
Last edited:
PIndelicato said:
I tried that when the issue first arose, and they did not seem interested in helping me at that time.

If you have a helpful contact there, please let me know and I will try again.
Click to expand...

Try asking for "technical service" not "customer service"

in just about all instances that will get you the smart helpful people.


Is your circuit protected by GFI a breaker, or a GFI outlet ?
 
Ask for Charles in the tech dept. he is a super nice guy and helped me out wiring up my 3hp motor.
 
OK, just had a good conversation with Tech Support (much more helpful this time), and I have two options:

-run another dedicated (non-GFI) line

-buy the drive posted above by javand (existing drives can't be upgraded). This apparently is the model with the modified software, but was told it was significantly more noisy and wouldn't necessarily guarantee flawless function.

Thanks to everyone who posted with advice.
 
Let us know how it works out Paul.. My drive ran fine on a gfi circuit I'd unknowingly hooked it up to until I touched another piece of un-grounded equipment and I got lit up.. I'm sure it wasn't good for the drive or the motor though, and it definitely wasn't good for me.

You might want to talk with the local inspector or whomever is the local code rep to see what "legal" options there are, there may be exceptions to the gfci circuit rule, I can't imagine it's ironclad for all uses, as I'm sure there are tons of industrial equipment applications where this would be a risk.

Maybe a DC controller and motor wouldn't be as susceptible to the problems? I dunno, I'm out of my depth with these concerns, but it's something to look into maybe.
 
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