VFD Troubleshooting - KBAC-27D for KMG

I feel all warm and fuzzy :). Solid core wires are really designed only for fixed installations where flexing and movement aren't an issue. Stranded cord for anything that will be flexed or moved much.

Glad we could help. And glad it's running now. You gotta take some video of your grinder in action and post it to youtube!!

--nathan
 
Nathan,

This is the first time that I've ever tried out this Youtube thing. Hope this works. Video can be seen HERE. (No audio commentary as I hate to sound like an idiot in front of the whole intra-web thingy. :D)

Erin
 
Erin,

AWESOME setup! I love the hidden motor and the VFD mounted out of the way. Makes for such a clean install! Very, very nice. :thumbup::thumbup::thumbup:

Now GO AND MAKE IT DIRTY!!! :D

--nathan
 
silver_pilate said:
Erin,

AWESOME setup! I love the hidden motor and the VFD mounted out of the way. Makes for such a clean install! Very, very nice. :thumbup::thumbup::thumbup:

Now GO AND MAKE IT DIRTY!!! :D

--nathan
Click to expand...

Yeah... the hidden motor is really cool. The motor's weight keeps tension on the belt. It'll be interesting to see if the motor tries to climb the belt or "bounce" if I try to really HOG some steel.

I'm getting all these tools but still ain't got no skillz. ;)

Erin
 
Hey Erin

Glad that it worked out well. That is a nice set up in the video. Are those old kitchen cabinets?

Take care.

Phil
 
Following this thread is inspiring me to get mine wired up. Unfortunately, mine accepts (220 recepts in the garage) the three prong plugs (dryer plug) and I am clueless on what goes where.

Great setup! love the video!


Bill
 
Bill

Do you have a VFD already? If you do, what type? It is not a big deal to connect the input of a VFD to a dryer plug.

Phil
 
Thanks Phil... those are actually old bathroom cabinets that I picked up on craigslist. A friend of mine gave me the benchtop. The combination seemed a bit low for comfortable grinding, so I had to set the cabinets on the four-by-fours to adjust for it. There is a gap of approx. 8" between the back of the cabinets and the wall (I am currently using it as a space to store hardwoods).

Bill,

My VFD was actually fairly easy to wire up... just don't use 10/3 romex :D. For this particular model, all you need is two prongs for the 240V hot legs and a ground (no neutral required). Make sure you do all wiring with the breaker OFF. ;)

As an aside, I actually used the grinder for the first time last night. No, not for knifemaking... nothing so glamorous. I was inspire to pick up one of those DeWalt portabands and built a bracket to mount it vertically on my wall. I used the grinder to clean up the edges and corners of my new 3/16"x9"x10" table for it. Pretty slick. :thumbup: I think that I may want to upgrade from a 2" to a 3" motor pulley one of these days though.
Erin
 
Phil,

Yes, I do have a VFD- KBAC-27D with a Baldor 2hp motor. For the life of me I can't tell which wire goes where because there are no colors assigned to the plugs. I guess I could take the box apart at the wall to figure this out eh?


Bill
 
Post a picture of what you're looking at... that always helps. Behind the receptacle you'll probably have a red wire, a black wire, a white wire and a green (or uninsulated copper) wire.

Now I'm an electrical engineer, NOT an electrician... so take any advice w/ a grain of salt. From what I can tell, most old 3-blade dryer receptacles have two symetrical slots (for red and black hot legs) and and an "L" shaped neutral slot (for white wire). See image below. The green/bare copper ground wire is likely tied to the j-box behind the receptacle.

032664199103md.jpg

(from Lowes.com)

Your VFD needs hot-legs and ground. It doesn't need neutral.

Again, all wiring work should be done with breaker OFF. If you don't feel comfortable messing with this stuff, hire a professional or get a friend to give you a hand.

Erin
 
I hope this helps. The dryer plug itself, I just followed a logical process to eliminate which was which. Middle I think is ground- This is where I get lost.

HPIM4579.jpg

HPIM4580.jpg

HPIM4582.jpg

HPIM4583.jpg

HPIM4584.jpg

HPIM4585.jpg

HPIM4586.jpg


Thanks!


Bill
 
Bill,

I am definitely not an expert, but...

A few questions:

1) Can you take a better picture of the inside of the motor junction-box? Are there only three wires coming out of the motor? What colors are they?

2) Can you take a better picture of the motor nameplate? What voltage is the motor (I am assuming 230v given your VFD)?

3) It looks like you only have three wires coming into the VFD from the motor (to terminals U, V & W). You should actually have four wires. You'll want to have a ground conductor from the VFD (the little screw w/ brass washer in the lower-left of the VFD... just down and left of U,V,W connections) to the motor case (there should be a grounding screw in the motor junction box).

4) Can you take a better picture of the inside of the dryer receptacle? Are there only three wires coming in from the panel? Looks to me like you may already be set. It looks like you already wired your power cord into the VFD. As long as the wire that is tied to ground in the VFD is the one connected to the "L"-shaped prong on the plug things look good.

You may want to invest in a simple electrical tester if you don't already have one. You can get one fairly cheap and it would REALLY help out on this type of project.

Erin
 
Erin,

There are only three wires on the motor itself.

Blue-1
White-2
Orange-3

As far as a tester goes, I picked up a cheap greenlee at Lowes today- It had a simple circuit tester in it that came in handy finding out what breaker to flip.

I'm not sure about the ground wire that you are talking about- I was thinking (dangerous, I know- thinking) that if the motor only had three wires for input, that is all that would be required for output (pigtail from motor to VFD).

HPIM4587.jpg

HPIM4588.jpg

HPIM4589.jpg


Thanks Erin!


Bill
 
Bill,

You should have four wires from the VFD to the motor. Three wires should be wired as you have shown already (from U,V,W on the VFD to the three wires in the motor box). You should also have a ground wire from the ground lug in the bottom-left corner of the VFD to the green case-grounding screw in the back of the motor j-box. I am attaching a couple of closeups of mine for reference.

3446058097_94223d08ec.jpg

3446872670_aa7e2822fd.jpg


Look at the green wire.

You should be able to find a short length of 4-wire #14 cord for about $1/ft at your local electrical supply store. Works great.

Erin
 
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Gaaaaaaaahhhh....I now see what you are talking about with the ground wire from the motor to the VFD! There is a spot for it, but I overlooked it!

I will report back, probably this weekend (school needs to take priority over this- for now- you know seeking a degree and all).

Thank you so much Erin!

Not sure how I can ever help except with advise on machining- I have 20yrs experience to draw from so if anyone ever needs help, you have only to ask or post and I will do my best to help!

Thanks!


Bill
 
Bill

In your picture of post #34, there are two silver screws that go into the metal of the junction box. They have the symbols made up of three parallel lines of diminishing length molded into the metal next to them. That symbol is the Ground symbol. Attach the fourth wire, usually green, to one of those screws. Attach the other end of the fourth wire to the chassis of your drive using the green tinted screw in the bottom left corner of the third picture in post #32.

It may be advantageous to go to an auto parts store or some place like Home Depot and get some crimp lugs. Get the kind with a ring on the end that will fit the screws like the green tinted one. You would want to use the forked lugs for the wires going to the terminal blocks for the inputs and outputs of the drive. You will want the ones with the yellow insulation if your wire is 10 or 12 AWG or blue insulation if your wire is 14 AWG. You may already have the tool to crimp them onto your wires. They make your installation much neater. They also eliminate the possibility of a stray strand of wire shorting across to the next terminal on the block.

Take care.

Phil
 
Erin and Phil,

Thanks so much for all the help! I couldn't wait to get this going so I finished it after work. Had to tidy up the wires like Phil suggested and throw in the ground from the motor to the VFD- Runs GREAT! The worst of it was swapping two wires to get it to run the right direction. I didn't even have to mess with the tracking which I really expected to be a minor issue.

Thanks for letting me hijack this thread and helping me out!

Bill
 
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