Ok, Scott, I don't know as much about the problem as you do, haven't worked on a Miprom 21 with A/B drive for 25 years, BUT, since when has a lack of knowledge ever stopped me from blabbing? (he heh!) Since no Miprom/Allen Bradley analog expert has chimed in for a couple days now, I'll expose my ignorance, and venture a chat.

I was wondering if your level up and level down sensors are symetrical from the door zones centerline, and set for a half inch of dead zone. Yes, I'm sure you thought of that, no doubt... But I have to ask it anyhow, because I don't exactly know what is meant by "dzu and dzd". Are those the two door zone sensors? Or leveling sensors? Anyway, if you run to the center floor, in both directions, can you adjust the leveling sensors to give a good stop? Is the cwt balanced correctly? Slow downs symetrical in the up and down? Motor field has enough oomph? (Volts) Howz it compare to the other cars? I've had cars that were adjusted wrong to compensate for other issues. Works until you disturb it.

Almost everytime I run into issues like this on older jobs, I find that the basics had been screwed with, over the years of late night quick-fixes, and goofy servicemen. When I get the basics corrected, everything falls into place. Even if this isn't the case with your situation, maybe something I've said will jog another thought with you, that will lead you to the answer. That's the way it is for me, when I bounce my thoughts off other people. fwiw

That's not around 3550 Wilshire, is it?

hi scott i dont know the equipment but have you checked that when it stops dzu/dzd (level up/down) usually trigger the brake set and stop. i have found that these readers can sense the dzu/dzd a bit far away than they should. leave the lift at a floor than is out and check on top that the readers are actually engaging where they should. could just be faulty readers. having the levels change when you adjusted things may mean its not but who knows. what about speed, can you slow down the lift then test floor levels, it might also be not getting the right slow down.

thanks guys for the input, vic, dzu and dzd are symmetrical around the leveling vane when car was at floor level. it was originally 3/8 inch off before i started, then i set it even. the car was leveling properly with no problems prior to this issue. up and down level speeds are even. I am not sure how the floor learn procedure knows that the car is floor level, as the dzu and dzd sensors are at least a couple of inches into the vane when the car stops. there are absolute encoding plugs at each floor but again they are calculated from the dzu dzd sensors passing through the plugged or unplugged holes in the floor level vane. there are no individual sensors for the encoding. my best guess is the program gets the input from the dzu dzd sensors coming on to the vane and then calculates the encoder pulse count to measure 1/2 of the distance of the fixed vane. i have been all over the manuals and can find no indication of how this is achieved, i am beginning to think the encoder is not counting revolutions precisely. maybe missing a few pulses at low speed. I can use the tool to adjust the level in either direction by up to .6 inches, but since is level in one direction, adjusting the off level direction makes the level direction off level by the same amount . uppo72, the sensors are definately engaging the vanes with no problem, but now that you say that, maybe one of the sensors is not triggering fast enough, i am guessing it is the encoder or the sensors, but i am not an expert on these cars, i did see one parameter relating to edge correction, but it was set to true, not sure what this does but i will dig in to it. hey vic, it is not 3550 wilshire, but i spent almost 15 years on the wilshire strip, and that address sounds familiar, is that the building where klsx radio was? brings back memories

scott, this levelling you describe sounds alot like a aussie lift called a miprolog. it used a course reader and fine reader for shaft position and levelling. the course reader told the lift what floor to count to then swapped to the fine reader to level in. these vanes are not what i was talking about (magnet readers) before. they have holes to count into floor level,small holes, this is the fine reader, and the notches you talk about tell the lift what floor they are on,large holes. this can be proved if you switch the lift off then on again, if the lift doesnt need a reset run then this is similar. it might just be software has told the lift to count say 20 counts when dzu/d is energized. the leading edge function will probably mean you might be able to adjust each floor or all floors. we were able to check the counting of these readers in flight to see if they were getting/missing signals from the test tool. also just had a thought that the lift might just have a regulated slow and stop s curve which is activated when you see both dzu/dzd sensors.

Scott, I think it was 3500 Wilshire, where as a newly 70% helper, I adjusted 9 Miprom 21s, with Allen Bradley drives, back in about 1986. Montgomery's head adjuster at the time, was Barry Freisen, who is now with the LA Dept Bldg + Safety, Elevator Division. He might remember something on those controls, or have some old books on them? I'll PM you his number at work.

Hey Scott,
My two cents here. Encoder on gov. or car top? If on the gov. and it utilizes that spring looking coupling, it could very well be broken. One direction engages the broken section right away, whereas the opposite direction pulls the two mating faces away, so in effect, the coupling turns, but the actual encoder count is a bit behind. If this is a gov. mounted encoder, remove the encoder base fastening screws, and the tiny allen screws (careful, there could be two set screws in each hole) that hold the coupling to the gov. shaft, then gently tug on it...if it's broken, you'll know it. I have found after doing a floor table that both up and down floor levels are compensated for using the "Floor to High" (or Low) feature and I think they are adjustable up to 1/2 " max., and one direction does not affect the other. I have yet to get "dead nuts" on all floors on a basement installation...like you, some are within an 1/8 of an inch which is the best I can get. If a rail type mount, my bet would still be encoder.

thanks elmcannic, Like you have encountered, i have set the floors, all 25 of them to be acceptable. I have not had a chance to get back to the job to experiment with, the encoder. it is still running with no complaints, but thanks for the info, i will check that out when i get back to the job. I guess if the coupling is half broke, it wont be long until it breaks altogether, then we will know for sure. hope i get back there before that happens. thanks again

Did you give a Barry a call? I PM'd you his number.