KMG Issues. Please help.

I would check the connections from the VFD to the motor. Unplug VFD and check the connections on the VFD board. ANd lastly remove and reinstall the wire nuts on all connections on the motor.
This has worked for me more than once.

Eyeeatingfish,
SOunds like your start capacitor, IE The round thing under the protrusion on your motor. Get a new one and you will probably be good to go.
Pull it off and get a new one on ebay unless you have a motor shop in town, then get it there. (DO it while sander unplugged)

CW
 
eyeeatingfish said:
My delta belt sander is dying. When I turn it on it cannot get the belt turning, I have to use my hand to push the belt, to kickstart it. Once it gets moving the motor will somehow be able to take over and get it up to speed.
You could try to kick start the belt with your hand. If that gets it moving then maybe you have the same problem as me... one which I haven't figured out yet
Click to expand...
Your Delta motor has a start capacitor. It's going bad. $5 part and you'll be back in business.

And the problem still really sounds like a bad connection. Loose wirenut or screw terminal on the VFD. I had a machine recently with a bad wire at work. Had to keep it running to finish the job so I did it one handed while holding the power cord up to keep the motor from stuttering. Loose wire in the housing fixed it.
 
Just curious do you have this plug into the right power source? What is the motor wired for 110v or 220v?
 
I'm fairly certain it's the motor. I tried what Dixieblade57 suggested about connecting the motor to the power and it still acts strangely.

The cord delivering power is the right gauge, but I will try a heavier duty wire if nothing else works.
 
Hooking up a 3 phase motor, to your residential single phase supply won't help you.
you're only giving it 1 of 3 phases

If that would work, you wouldn't need the vfd.

First thing I would have done is READ THE MANUAL


We need more info
What can you tell us?

That video doesn't show much

Back in post 6, you said "No trouble indicator lights."
But there ARE

http://www.kbelectronics.com/manuals/kbac_manual.pdf
- check page 22 of the manual TABLE 7 – DRIVE OPERATING CONDITION AND STATUS LED INDICATOR

"Status light flashing orange and red" ?? as you say in the video

There is no orange

There is fast and slow
There are 3 colours, green, red and yellow.


Since you can see it best, look at that table and figure out what error codes you have in those lights.


MJV suggested that a week ago
What have you figured out with the error codes since then ?



We still need much more info, we're smart, but not clairvoyant.

Who connected the VFD and motor, you, or did you buy it from rob?


Is it connected to 110 or 220?

What kind of breaker? if it's 220, are the breakers tied together so they both snap off together?
are both hots coming from different sides

What horsepower is the motor

Is it a sealed motor TEFC, or TE something, or can you see through the frame to the windings?



How long has it worked before it stopped working?
Or is this a new hookup that hasn't' worked yet?

What have you changed from the time it worked, to the time it stopped working?

Find the breaker that it is on, snap it off and snap it on again


How is it plugged in?
Is it plugged into that skinny little extension cord below the controller box?
From here it looks like one of those multi plugs on the female end - I've always had trouble with those
Is it a grounded plug/cord? from here it looks like just 2 blades

Eliminate that extension cord- just for fun pull on the ends of that cord with all your strength- can you pull the plugs off?
Use as short as possible 14, or 12 gauge wire to plug it into the wall.
long skinny extension cords may give under voltage errors, or be easily damaged.

You're not using the outlet behind the grinder, where are you plugging it in?


Eliminate that cord and plug

Plug it into a different outlet if it's 110

Disconnect it from power and then check all connections
by check I mean use all your strength to pull them apart, good connections should not come apart
those wire nuts, marettes work but people have trouble using them.
The little box on the motor, open that up and check those connections are tight
Use all your strength to try and pull them off.

Open up the cover of the VFD and be sure the screws are tight
be sure that the jumper wires are all on securely


If this is a new installation on 110 that hasn't worked yet
be sure that the jumper in the VFD is on the 110 spade
It comes factory default as 220


Is it plugged into a ground fault outlet, or are there ground fault outlets on the circuit?
Eliminate that.


We need more info
What can you tell us?

In reading my response, everything I've said has already been written above by others
try it all

Or take it somewhere where they can properly diagnose and test- all it takes is $
 
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If you have proven it's in the motor.

Then you can begin to isolate the problem! First some questions is this motor 120V or is 220V?

Does the motor arc inside excessively when in operation?

Does this problem exist from start up? ( If so it may be a starting capacitor) The round looking canister piggybacked to the electrical on the motor!

I just went back and looked at some of your posts and it maybe a bad field on the motor, Check for excessive arch inside the motor! That is not good if it is they can be rebuilt but the excessive arching is burning up the field.

Is the motor getting hot when it starts to slow down?

Give me some answers on those questions and I may be able to help you isolate the problem better.
 
Dixieblade57 said:
If you have proven it's in the motor.

Then you can begin to isolate the problem! First some questions is this motor 120V or is 220V?

Does the motor arc inside excessively when in operation?

Does this problem exist from start up? ( If so it may be a starting capacitor) The round looking canister piggybacked to the electrical on the motor!

I just went back and looked at some of your posts and it maybe a bad field on the motor, Check for excessive arch inside the motor! That is not good if it is they can be rebuilt but the excessive arching is burning up the field.

Is the motor getting hot when it starts to slow down?

Give me some answers on those questions and I may be able to help you isolate the problem better.
Click to expand...


There are 2 different posters with 2 different problems in this thread
Zbacon is the one I'm referring to.

He hasn't proven the problem is in the motor, maybe yes, maybe not

He is using a KBAC27D for variable speed - this means a 3 phase motor at 220 3 phase
As far as I know, there is no starting cap in the three phase motor.
At least on the 6 i have, they have none.

As far as I know, a motor with no brushes should have Zero sparking inside the motor.

Motors like a portable power drill have brushes and you can see sparks




The other poster was using single phase and may have needed a starting cap
 
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Z Bacon The count has given some great suggestions. It is apparent that you are not skilled in the wiring area. Not anything we have not been through (being new). Now the first thing is you need to make sure your motor is wired properly. You will need to take off the electrical plate. PLEASE UNPLUG AND MAKE SURE NO POWER IS PRESENT. Look at the table on either the motor plate or on the underside of the electrical plate. Make sure the wires are connected for low voltage (210-220v) and not high voltage. It is apparent that you are running 110v in and 3 phase out. The next thing you need to do is verify the correct wiring inside the VFD. You might need to get on the phone with Rob to double check the set-up. If all these are correct and the wires are all tight (please check as you go along) the next thing to try is connect another motor. If you do not have one you might have to bite the bullet and take it down to a motor shop and have them check it out.

I still think you have dropped a leg. Whether it be a wire loose or an output issue from the VFD. The high pitch whine from the VFD is normal. At least all the VFD's I have used produced them. It is one drawback using them. It can give me a headache after a while. Good luck but you just might need to take it down and have it looked at.
 
It is your VFD, Rob will tell you the motors are "Bullet Proof" and he has never had problems with them. I had the same issue, the sputtering and jumping when running. I sent the VFD Back and Rob took care of it. Talk to Rob tomorrow.
 
A C Richards said:
Z Bacon The count has given some great suggestions. It is apparent that you are not skilled in the wiring area. Not anything we have not been through (being new). Now the first thing is you need to make sure your motor is wired properly. You will need to take off the electrical plate. PLEASE UNPLUG AND MAKE SURE NO POWER IS PRESENT. Look at the table on either the motor plate or on the underside of the electrical plate. Make sure the wires are connected for low voltage (210-220v) and not high voltage. It is apparent that you are running 110v in and 3 phase out. The next thing you need to do is verify the correct wiring inside the VFD. You might need to get on the phone with Rob to double check the set-up. If all these are correct and the wires are all tight (please check as you go along) the next thing to try is connect another motor. If you do not have one you might have to bite the bullet and take it down to a motor shop and have them check it out.

I still think you have dropped a leg. Whether it be a wire loose or an output issue from the VFD. The high pitch whine from the VFD is normal. At least all the VFD's I have used produced them. It is one drawback using them. It can give me a headache after a while. Good luck but you just might need to take it down and have it looked at.
Click to expand...

I see said the blind man as he picked up his hammer and saw and proceed to work!

I wasn't sure what I was looking at and couldn't get Z bacon to answer some key questions. When folks ask for advice sometimes they need to keep in mind that the people you are asking are not there and unless they have experienced a similar problem themselves, they may not be sure what you are looking at. When you ask for advice give as much info and or pics as possible to help with diagnoses.

I will be very honest VFD control I know very little about but, I do know some about motors. Usually enough to figure out somewhat the area of the problem at least.
But after seeing AC Richards post it sounds like he may be spot on.*110v in and 3ph out I know enough to know you better be tight and right on your connections, I had a friend that had a similar system and all I knew enough to do after he got through the technical explanation of how it all worked was to smile and nod in the appropriate places!:eek:


And for goodness sakes, call Rob at Beaumont! He is a stand up guy and won't hesitate to help out when possible. The man supplied me with all sorts of info, even when he knew I was building a KMG clone. Why because he is a stand up guy and knows he has nothing to fear, his product is his name and the whole thing is built to be bullet proof. That doesn't mean one won't break down because it is manufactured by humans! It does mean though that Rob will probably know before anyone else what is wrong if you got a problem. He has either experienced the problem or knows someone that has.
Beaumont Metal Works, Inc
1473 Showcase Dr.
Columbus, Ohio 43212
Phone:(614) 291-8876 (9-5 EST M-F)
 
I thought the idea was the VFD powers the 3 phase motor. As long as the VFD takes the standard 110 in it will handle the voltage conversion to run the 3 phase motor with variable frequency.
 
Thank you for all the help everyone. I will all Rob today and ask about the VFD, which I am almost certain is the problem. However, it has not been giving me much trouble lately. I unhooked everything and rewired it and it seems to be working beautifully now. In any case, when it does sputter like in the video, I've noticed that I can just move to another project that doesn't require the belt grinder and by the time I am done with it, the belt grinder runs perfectly. I will still be calling Rob though. Thank you for all your help and advice everyone. I really appreciate it!
 
Rob is a fantastic guy. I was having similar problems with my identical KMG. It would work fine for some time, then start jumping like the belt was loose. At slow speeds it sounded like the motor was squeaking. I sent my VFD back to Rob to be tested, but he couldn't find a problem with it. He even had it set up running for 5 days straight without a problem. He sent me a brand new one anyways and now takes my old one to hammer-ins and demonstrations. My grinder was a little over a year old at the time. It solved my problem.
 
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