Kbac & motor help

M

muddtt

Joined
Oct 22, 2018
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Was wiring up my kbac 24d to my motor. Had it working fine but it was running backwards. went to change two wires around. In the process I touched a wire with my finger and got a small shock. It threw the GFCI breaker so I reset that, but upon reconnecting everything it won't spin the motor anymore. The kbac has red flashing light for short circuit. I double checked the wires and they look ok. Any ideas or thoughts?
 
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The Manual seems to suggest testing your motor winding and or connections.
 
Thanks, I'll bust out the multimeter tomorrow and give it a try. Crossing my fingers...
 
I have to ask - why were you moving hot wires around?????

Start by resetting everything. Turn off breaker at fuse box. Unplug the VFD for at east five minutes ( don't plug back in yet). Turn everything to OFF and set VFD dial to zero. Check the motor wiring with no power to make sure it is all wired right. Look for stray wires that are touching, etc. Turn on breaker. Plug in VFD. Turn on the VFD power switch. turn the speed switch to 50%. Press/flip the RUN switch. If you still get the light, unplug everything and double check the wires to the motor for shorts or crossed wires. If nothing is found, call KBAC tech support.
 
KBAC has 2 different VFD's and one is specific to run off GFCI circuit....the More common unit will not operate on GFCI circuit make sure your unit is designated for GFCI. Since you are operating on 110v circuit run an extension cord to non GFCI outlet see if it spins the motor and gives you a Green Light.
 
Wow! Busto has seen something that I skipped right over ... a GFCI breaker. He is correct, it is wise to run the VFD off a standard breaker.

Same goes for many devices that make waves in the power line. I couldn't use a wireless plug-in intercom from the shop to the house because it would trip the GFI breaker for the utility room where the other unit was in the house. The AF superimposed on the power wires to send the voice was seen as a voltage variation in reference to ground and the breaker would trip.
 
Well to answer the easy question first, I was working with hot wires because i'm dumb. But that might give dumb people a bad name so I'm what ever is worse than dumb. I kinda took the start stop switch for an on/off.

As far at the GFCI, it was running backwards before I shorted it out. My morning project is to check the motor windings. I think this video should be the proper instruction to test the motor??:
If the motor checks out I'll try giving KB electronics a call.

Thanks for all the replies. I'll update as I go.
 
Just to check ... you do know that you have to push the STOP/RUN/START switch upward again from the RUN position to START every time the grinder is turned off. It isn't enough to just turn the switch back to run after turning to off. (at least that is how it is on some KBAC units). Also, make sure the power switch is ON as well as the Stop/Run/Start switch.
 
I would try plugging into a non GFCI circuit, made sure the switch is on stop, and then see if you still get the error.

Also, just to be clear: You switched 2 of the U, V, or W leads, and NOT L1, L2.... right?
 
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Yes, I'm aware of the toggle'd start stop switch.

Yes, I did switch the correct leads. I'm guessing that if the GFCI was the problem it would just blow the circuit again. But that hasn't been happening. I've also tried it on multiple outlets that have worked for short testing when I initially got the VFD and it still isn't working on those.

I finished checking the motor according to that video and it appears to be ok. Also, contacted KB Electronics. They had no advice for me over the phone. Just to send it in for repair. So I guess my belt grinder project is on hold for awhile. Will spinning the belt by hand give me a good enough idea of how the belt is tracking to test the setup?

And thanks again for all the replies.
 
Bummer on the blown VFD - good luck on the repair. Spinning the belt by hand will give an idea how tracking is. It won't be exact, but will indicate if tracking is so far off the belt runs off pulleys.
 
No, hand spinning won't work well for tracking adjustment.
Something must have fried in the VFD when you were in there. KBAC will make it run again.
 
The OP is talking about a new grinder just being setup for first time. While spinning belt by hand won't adjust tracking perfectly, it will be close enough for setting up a new grinder to make sure the belt won't run off wheels when motor is turned on. After motor is turned on (low speed best) the final adjustment is done.

I can spin my belt by hand on both 2X72 grinders I had and adjust tracking so belt would stay on.
 
I can spin my belt by hand on both 2X72 grinders I had and adjust tracking so belt would stay on.[/QUOTE]

I do this Every Time I Change belts
 
Maybe to stay on the wheel you can hand spin the belt, but the belt will need to be running at full speed without your hand ( or anything else) toughing it to adjust the tracking for an exact placement on the wheel/platen.
 
Just to update. Sent my VFD to KB Electronics. Something was blown on the board. Was like a $20-30 fix. Got it back and everything is working great now. Turned out to be a nice pause cause I could take my time painting the thing and giving it a good amount of time to dry. Thanks again everyone.
 
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