# KBDA-29(1p) Startup Issue



## jbolt (Jun 13, 2018)

I powered up the KBDA-29(1p) and anything over 15Hz the motor stumbles and the Overload LED blinks. I have set the motor Amps to the name plate of 7.6. AC power is good so not sure where to go from here. Maybe something in the Operating Parameters?

Photo of the motor nameplate and video of what is happening.

https://drive.google.com/file/d/0Bxq8HLuwIa5jNTdGbFlCNEljdktJQ210aVlsaFB1ay1uZFJB/view?usp=sharing


----------



## BtoVin83 (Jun 14, 2018)




----------



## jbolt (Jun 14, 2018)

BtoVin83 said:


> View attachment 269614



I have the (1p) version.


----------



## jbolt (Jun 14, 2018)

I was able to get the motor to spool up with the acceleration time set to 10 seconds vs the factory default of 1.5 seconds. Between 20Hz and 50Hz the motor still does the wa-wa-wa sound but no overload LED and then smooths out at 50Hz +. My intent is to run between 30Hz and 90Hz. Based on other motors I have running on VFD's it should run smoother at those frequencies. There are settings in the drive operating parameters I'm not sure about. 

S-Curve Time (Accel, Decel), Seconds 0.00 - 30.00, Default =0
Skip Frequency (Hz), 0.00- 240.00, Default =0.00
Skip Frequency Bandwidth (+- Hz), 0.00 - 2.00, Default =0.00
Boost Value (%), 0.0 - 28.0, Default = 7.0
Switching Frequency (KHz), 8,10 or 12, Default = 8
Flux Vector Compensation (%), 0.00 - 10.0, Default = 5.0


----------



## mksj (Jun 14, 2018)

The adjustment parameters are pretty limited, sometimes you need to do a motor auto-tune so that the VFD loads the motor's operating parameters. This has made a big difference in a couple of recent installs where the motor was coggy until the Auto-Tune was done. There is a description of a static auto-tune on P8 of the manual, but no reference to how this is done. You may try to increase the Boost Value % (3.11) which should increase low end torque. I would try to increase it in 3% increments to maybe 16% and see if there is any improvement. There is also some tuning of the Flux Vector Compensation (3.16).   I have also had some motors that did not do well with S curve acceleration and longer acceleration times, but the default S value for the KBDA is 0 which should be linear. You might try 3-5 second acceleration times. Beyond that, you might give a call to KB electronics tech.


----------



## jbolt (Jun 14, 2018)

mksj said:


> The adjustment parameters are pretty limited, sometimes you need to do a motor auto-tune so that the VFD loads the motor's operating parameters. This has made a big difference in a couple of recent installs where the motor was coggy until the Auto-Tune was done. There is a description of a static auto-tune on P8 of the manual, but no reference to how this is done. You may try to increase the Boost Value % (3.11) which should increase low end torque. I would try to increase it in 3% increments to maybe 16% and see if there is any improvement. There is also some tuning of the Flux Vector Compensation (3.16).   I have also had some motors that did not do well with S curve acceleration and longer acceleration times, but the default S value for the KBDA is 0 which should be linear. You might try 3-5 second acceleration times. Beyond that, you might give a call to KB electronics tech.



Thanks Mark, I'll try a few things. 

In the manual they mention a detailed programmable function list as something that can be requested so I will see if I can get that. 

Any idea what switching frequency parameter does?


----------



## mksj (Jun 14, 2018)

Switching frequency parameter 3.15 is the switching frequency in kHz, it will not change the motor operation. Newer motors do fine with 12 kHz, older motors are best kept around 6 kHz or less but this generates more audible noise. Higher frequency tends to heat the coils a bit more and be harder on the winding insulation, but this is not a problem with an inverter rated motor. Could not find any further information on the parameters at the KB site.  Sometimes VFDs and motors just do not work well together.


----------



## jbolt (Jun 15, 2018)

I tried some of the parameter changes but not much improvement. The minimum acceleration time is 7 seconds. If I increase the boost over 8 I get a -SC- fault which is a short circuit fault. Lowering the boost below the factory default of 7 does not make a difference. Changing the flux compensation did not seem to do anything. I tried all the switching frequency settings and all that does is make the pulsing on startup quicker. I have a call into KB. We'll see what they say.

As good as I can get it.


----------



## jbolt (Jun 18, 2018)

Looks like the motor and controller are not compatible. I wired the KB controller to the Marathon motor on my lathe and it works as is should. I then wired the motor to the Hitachi drive on my lathe and was able to get it to work. Not sure what the issue is but I suspect the limited adjustibility of the KB drive cannot be tuned for that motor. Now to find another motor.

Sent from my SM-G955U using Tapatalk


----------



## ttabbal (Jun 18, 2018)

I don't have that controller, so this may not help... However, I was setting up a new VFD for my Bridgeport last night and ran into a bit of trouble. It wasn't running like it should. After poking around a bit, I realized there is a parameter labeled "Rated motor frequency". The default was 400Hz. No idea why as I've never seen a motor that wanted that high of a frequency. Changing it to 60Hz made it run great at all the speeds I wanted it to run at, about 20-100Hz. My VFD is a Chinesium special, so your nicer unit might not need something this simple.


----------



## jbolt (Jun 19, 2018)

ttabbal said:


> I don't have that controller, so this may not help... However, I was setting up a new VFD for my Bridgeport last night and ran into a bit of trouble. It wasn't running like it should. After poking around a bit, I realized there is a parameter labeled "Rated motor frequency". The default was 400Hz. No idea why as I've never seen a motor that wanted that high of a frequency. Changing it to 60Hz made it run great at all the speeds I wanted it to run at, about 20-100Hz. My VFD is a Chinesium special, so your nicer unit might not need something this simple.



On the KBDA drive they come from the factory with the native Hz set at 60Hz and then the user can change to 50Hz if need be.

KB Electronics technical support has been amazing. The engineer who has been helping me has gone out of his way to find a solution.  He had me try many different parameter settings and I had a direct line to him for communicating back and forth.  During the troubleshooting I sent him video of all the different configurations we tried and he finally came to the conclusion that the motor I have is not fully compatible with that drive. Mostly due to being a 3600 rpm motor. Apparently the KBDA drive doesn't do what he called "dead time compensation" which affects some 3600 rpm motors. I believe this is something they are working on to improve. This affects my motors behavior from about 40Hz to 55Hz. He said it will work fine with a 1800 rpm motor. The bad news is my belt grinder design is based on a 3600 rpm motor so getting another 3600 rpm motor has a good chance of not working. That left me with looking for another drive controller.

I was blown away this morning when I got a call from KB Electronics wanting my address so they could send me another drive controller that will work with my motor at no cost. Their only stipulation was that I call them back and let them know how it works. I get to keep the drive controller I already have to use for another project. WOW! 

The drive that will work with the 3hp 3600 rpm motor is the KBCA-29(1p). It's not digital with a key pad but I'm not complaining.


----------



## ttabbal (Jun 19, 2018)

That's impressive support!


----------



## mksj (Jun 19, 2018)

Nice to see that level of support, much better than I have experienced with a few other VFD manufactures. I have had some combinations of VFDs and motors that just wasn't a good fit no matter what I tried, mostly 2 speed motors (not constant Hp ones). I like the sealed KB units but I have had programming and braking limitations for the type of systems I have worked with. One thought would be to go with an 1800 RPM motor and push it up to 120Hz for high speed grinding. Would have better low end torque and Hp at the slower speeds. The Baldor has a 6000 rpm top speed.
Deleted the WEG listed it was footless, but there are other inverter motors that should easily go to 3600 RPM Teco is a good choice and cost effective.
https://www.ebay.com/itm/TECO-Max-E...0014-1-HP-1745-RPM-230-460V-143T/182489426107
https://www.ebay.com/itm/BALDOR-1-HP-3-PH-INVERTER-DRIVE-MOTOR-NEW/191731639588

Note: Can't use these KB drive for 120Hz, most are 60 Hz max +10% if I recall.


----------



## ttabbal (Jun 19, 2018)

That's how I run my grinder motor. It's an 1800 run 20-120Hz. With the wheels I have, the belt runs fast enough that I don't use the highest setting much.


----------



## jbolt (Jun 19, 2018)

mksj said:


> Nice to see that level of support, much better than I have experienced with a few other VFD manufactures. I have had some combinations of VFDs and motors that just wasn't a good fit no matter what I tried, mostly 2 speed motors (not constant Hp ones). I like the sealed KB units but I have had programming and braking limitations for the type of systems I have worked with. One thought would be to go with an 1800 RPM motor and push it up to 120Hz for high speed grinding. Would have better low end torque and Hp at the slower speeds. The Baldor has a 6000 rpm to speed.
> https://www.ebay.com/itm/WEG-00118E...-143-TC-Encl-TEFC-Inverter-Motor/113014134886
> https://www.ebay.com/itm/BALDOR-1-HP-3-PH-INVERTER-DRIVE-MOTOR-NEW/191731639588



Hmmm.....those are 1hp motors? I'm running 3hp. 

To get the SFM I want with an 1800 rpm motor I would need to increase the drive wheel size which changes the geometry of the drive system. Currently I am locked into a 3600 rpm 182T frame motor unless I make physical changes to the grinder frame which is built and painted. 

I should have the new drive early next week and see how it goes.


----------



## jbolt (Jun 19, 2018)

For informational purposes here is a video of the best we could get my motor to run with the KBDA drive.


----------



## mksj (Jun 19, 2018)

My mistake, I am use to seeing smaller motors on these drives, usually 1-1.5Hp. The motor seems to have vibration modes and seems to shudder from ~55-40 Hz, should be silky smooth.  Better to try a new drive first, would be curios to see how the analog KB drive works. If a new motor, I have had good success with the inverter rated Baldor, Marathon, Teco and Lincoln. OK some 3Hp motors, 4 Pole. The first is $100 plus shipping if you need to go that route. I guess this is not your typical portable sander....
https://www.ebay.com/itm/TECO-WESTI...HH8P-FRAME-182T-230-460V-1755RPM/282893388247
https://www.ebay.com/itm/NEW-MARATH...864455?hash=item46744c3e47:g:fdcAAOSw4HNaV4MF
https://www.ebay.com/itm/Marathon-1...3-Phase-Hazardous-Location-Motor/232725006158


----------



## jbolt (Jun 19, 2018)

I have that same E470 Marathon motor on my lathe. Very nice motor. The motor I have was a trade so I'm sticking with it for now. We'll see how it goes with the other KB drive.


----------

