KB Variable pulling error code --

[Burchtree]

Got a KB Electronics KBAC-27D set up to run 2HP and for some reason it pulled up (from what I can tell from their website) an "undervoltage" code (quick red/yellow flash). It is worked fine for 2 years as it is, so what could change and cause this?

http://www.kbelectronics.com/manuals/kbac.pdf

Any help would be much appreciated - -

 

[rfrink]

Michael, Does the drive still run? If so, when do you get the error. For example, "when you turn the speed up quickly...but not when you turn the speed up slowly".

..Or when you turn the control to "stop".

Of course, double check all of your electrical connections for tightness. Cinch up the wirenuts and terminals.

Have you moved the machine...perhaps to an outlet that is further away from your electrical service...or perhaps running it on a long extension cord. Is there a new machine in the shop that might be hogging up all the electricity?

Basically, have you changed anything recently that also corresponds with the new error.

I really don't get hung up on the "specific" error description. Even though the manual may say..."undervoltage" ..they don't say where the voltage is being monitored. It could actually be a buss voltage on the circuit board and totally unrelated to your supply voltage for example. I've found that you really can't take the manual descriptions literally.


My 1st thought is that you might need to adjust the trim pots for a slower accel and slower deccel. Perhaps over 2 years, your machine has loosened up a bit and is retaining more inertia when you shut it down...or requiring too much current to ramp up when you start it. Just a few theorical scenarious.

What is this controller running? Disk? grinder?


-Rob

 

[Burchtree]

It is running my main KMG. I haven't changed anything at all lately and that is what is so weird to me. The LED pulls an error when I turn on the power to it. It blinks one green, then a quick red/yellow/green. Weird. If I hit the "start," the motor kicks in for nanosecond and that is all.

 

[rfrink]

Here's a couple things to try...after you've made sure that ALL electrical connections are tight and secure...including the plug on your cord, the screws on the terminal strip in the controller...and the connections in the motor.

To trouble shoot the main power on/off switch for faulty contacts, unplug the controller from the wall. Then remove 2 of the wires from the power switch..say 1 white and 1 blue. Use these two wires as jumpers. Disconnect the otherwires from the switch to the circuit board on the L1a,b and L2a,b terminals. Then place a jumper across L1a and L1b, and the other jumper across L2a, and L2b. This removes the power switch from the circuit and the controller will be "on" when you plug it in the wall. From there, flip it to "run" to start the motor as ussual. If it works..then the switch is bad.

Also, check the trim pots...mainly accel and deccel. Turn them clockwise ..say 1/4 turn just for testing. This will make the grinder accelerate very slowly up to full speed...and slow down very slowly as well. This is just to check that these adjustments are not causing the fault by being set too aggresisvely. If it works, then readjust them untill you get the desired accel and deccel without a fault.

Also, check all the other trim pots and make sure that they are not turned all the way to the limits. If you have one turned all the way clockwise for example...back it off just a touch so it's not actually at the limit.

And that's about all I can think of for now.

-Rob

 

[Burchtree]

Thanks for answering my questions on the phone Rob! So far, I've got zippo. I can't find a single reason for it to be bad and I did find a 1.5 HP to test it on to no avail. Is there any way to test the pot?

 

[Burchtree]

Not the pot -- @#$%#$^%^!!!!

 

[pso]

Hey Micheal

Have you tried disconnecting the wires to the motor from the drive? The manual for your drive seems to say that the Undervoltage fault is referring to the input voltage, not an internal point. A shorted motor can make the drive think that there is such a fault. If that does not make the fault go away and you have not changed the settings then you may have to send it in to the manufacturer. It is then likely to be some component inside that has gone bad. Without proper schematics for your drive, access to it and access to replacement parts it is difficult to recommend anything else.

From my quick look at the manual, I get the impression that you have to remove the front cover to get at the trim pots on this drive. Are you using the proper glands/seals around the input and output wires to keep the metal dust out? If not, you may have metal dust inside causing you a problem.

Phil