Having issue with this old Miprom 21. Has been modded to an AC machine, using a HPV-900 drive. Do not know how long ago it was modded to this setup.

My issue is that on my analog direction inputs on drive I am only getting positive VDC in both directions. I saw that the input was being fed by the maroon plug on bottom right of my relay pilot board.

I switched out the relay pilot board being hopeful that was my issue. No dice. I guess my main question, is which board has the logic to tell the voltage to swap polarity in the down direction? MSU, CPU, PIO?

Customer is on an outage right now in a power plant and they NEED this freight elevator so you can assume how much pressure is being put out to "just get it going"

Check the Analog ADC1 parameter. U should see a positive and a negative. Try making the negative like .001

On second thought, this prolly won't work on an HPV900. It has to b integrated with the cpu for the parameter to work I think.

Sorry for the late response John Jay. I spent a good part of the day working on it.

I think I got it fixed. I sat down and started reading anything and everything I could find in Kones "little black book" I'd hate to see what they call a big book.

Anyways, I did find where it started velocity command was sent through the MSU board. Had a MSU, PIO, and a CPU board sent to me. PROM board will be sent Monday. Apparently PROM board must be programmed by engineering.

Went ahead and replaced MSU and PIO board. Went through and did new hoistway table and elevator is running like a champ.


I do have a question though. Say I wanted to replace the CPU and PROM board. I believe I read that I would have to uncouple motor from machine to run a learn on the motor/drive. I am using a computer purchased from Kone Spares with Miprom 21 Service Tool program loaded onto it but when I went to look at ADC1 parameter under drive adjust, it started "this function not integrated at this time"

Would I be up a creek without a paddle should I need to replace CPU? I am learning on my own home to use this service tool and to be honest replacing the CPU worries me.

the ADC 1 parameter was for the drives from Allen Bradley. All those field programmable params are not integrated with with the Baldor, or HPV drives. You can change the CPU with no problem. If you remove the chip with the floor table,it is plug and play. I think it is the u17, or u38, or u37 as I recall. It depends on the date of install. Remove that chip from the old board and use it in the new board.

I've never worked on a Miprom 21 that you had to do anything like that, unless its a permanent magnet motor that needs an encoder alignment. I have worked on a couple with HPV900 drives and if I remember correctly, it was setup more like an analog DC drive i.e. all discreet between MSU & drive so you wouldn't have access to the drive menu on the service tool. You probably had a bad MSU card, all the pattern manipulation happens there except when NTS clamps. replacing the CPU is no big deal, just move over the PROM board, do a HW scan & touch up floor heights.

Thank you both for some valuable information! 15 years ago as a helper on mods, all I needed to be able to work on a miprom was a sawzall and a hammer as we would have just yanked this sucker out. Some of my customers now in the industrial side have some ancient equipment and it makes me learn fast, on the spot.

I'd take those Miprom 21s over a KCM or a Schindler anything!

Well guys, the same issue has shown up again. I'm at a loss. I had another MSU, CPU and PIO board on hand, swapped out each by themselves and then tried all three at same time and can not seem to fix issue. Still have the same voltage input to the drive.

Any other ideas I need to be trying?

So you were only getting positive pattern to the drive correct? Is that still the case, even on inspect? Same positive voltage whether you try to run up or down?
If you check the pattern on the NTS board do you see the same thing VC in to GAN as VC our to GAN?

I think the earliest point you can read the VC is on the CN5 ribbon cable (9-10) on the Relay Pilot board. Or a little easier on the J2 plug (10-14) but no reason that should be different than the test points on the Relay interface. But if it’s always positive here, I would try pulling the J8 plug just to make sure nothing down the line is affecting it. And if it’s still always positive, are all your power supply voltages good?
Hey, I wonder if you have a dip switch in the wrong position on the MSU. Do you have the procedure for setting up the VC command?

Thank you for the reply. I did check all my power supply voltages and they all were in spec to the book. I will be onsite tomorrow to further troubleshoot. Job is 4 hours away.

And yes on inspect voltage stays positive. This is a 75fpm car and on inspect while it's in this state, shows a reading of +1.536vdc in up and down direction.

I’m wondering if when you flip SW1 switch 1 & 3 during the Velocity Command adjustment you see the negative voltage.

Have you checked all your ground reference points. GDR starts at the Miprom II power supply. I don't have a print for the drive you are working on. Page 7 on mine shows the power supply. L1A is fed in Then follow the GDR out and make sure you haven't lost a ground somewhere. If it ran for a while I would be looking for loose connections. Also GAN is another reference point, and L1A is system ground.

One more thing, I have worked many a power plant outage. If this is a coal fired plant, the corrosive atmosphere causes the pins, and plug in cables to oxidize. you may want to clean and check these connections also. Don't stress if the ugly Plumbers, Pipe fitters and Iron Workers have to walk. Most of them need the exersize.

Just a quick update. Upon arrival checked my power supply voltages on the relay pilot board. All was good......... except my -12vdc. Had zero bolts. I ordered a power supply this morning and should have it in hand tomorrow morning.

Power supply. If you have already tried msu, that's what id do next