VFD Wiring Help

KnuckleDownKnives

KnuckleDownKnives

Time to make the doughnuts..
Joined
Feb 12, 2015
Messages
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Hi all. Trying to finish up wiring my KBAC-29 drive to a 3hp motor. I have the motor hooked up good, but can't figure out what to do on the line input. I know the 2 hot leads go to L1 and L2, but I cant figure out where the common goes since the book says L3 is only for 3 phase input and I'm using 220v single phase input.

Does the common wire go to the ground lug inside the drive? And does the common get hooked to the common in the breaker panel, or does it go to ground?


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Ok so I just went ahead and hooked the 2 hots up and a ground without a common. Seamed to be hooked up correctly as everything works right. Had to swap one leg on the motor to get it going in the right direction, but other than that seems to be gold to go.

Figured if I just went to ground to ground first I couldn't mess anything up.
 
I knew it would work that way but I'm not certain it's right.
 
Yeah, I'm not certain it's right either. It runs good turning up the rpm, but when I turn it down it's cutting off. Looks like overvoltage from the book. Might have to post a video and see if someone can help me sort it out. Idk at this point.
 
Firstly, quit referring to anything to do with 120v or 240v singlephase as "common".
I am guessing you meant to write "Neutral" ?
Then its correct that neutral is not connected to anything.
The two energised conductors connect to "L1" & "L2",
Earth Ground connects to the grounding terminal, (not "Common", Neutral or anything else)

Fwiw, Cant comment specific to this KBAC,
But some VFDs want to see input on all three input terminals even if singlephase is supplied. One simply fits a jumper between "L3" & "L2" .
 
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pleasanthill said:
Anyone got any ideas whats going on?

Click to expand...

Is there a DC brake function? My vfd will do this same thing but only when running my big 12'' wheel, if I turn it down too fast, because the inertia of the wheel overloads the brake. I had to turn down the deceleration time to keep it from happening constantly.
 
Ok after some reading I increased the deceleration time above 10 seconds and it seams to be smoothing out.
 
Sounds like you got it figured out, but to answer your initial question, you only need two hots and a ground. The neutral conductor is not necessary.
Both hots wire into L1 and L2, and your ground will attach to any of the green screws inside your VFD.
 
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