have a new job with 411 controls, it is a mod job. problem is we are getting intermittent complaints of car stopping in flight. one of the complaints was the car was traveling down from 19 and a few floors into the run the car stopped abruptly and the pi changed to the bottom floor, then they say the car ran all the way to the bottom floor, and went back into service. we have been logging a 2812 dfc/dcl fault, we have been thru all the locks, gate, dcl etc. and have never seen the car fail while we have been on site. along with this fault is a 2831 position recovery count error, and a few 2100, 2101, PSR big positive and negative slip, along with a few relieving errors. not sure if this is causing the car to shut down, as the other cars in the bank also seem to log the PSR and relieving faults, along with the 2812 door fault. I'm concerned with the 2831 fault, do you think clipping a door lock at hi speed would cause the pi to change to the bottom floor and then do a recovery run to that floor, i have checked the battery of the mlb board and it is good. 2831 fault does say maybe bad mlb board, anyone have any ideas. don't have to much experience on these units, so not really sure what errors really cause a shut down, and which errors are just a nuisance.

The slip faults are probably from the abrupt stop. Check the encoder wiring for loose wires, loose plugs, or loose flex coupler or broken coupler.

Are your lock's ECI? Also it must say the floor it logged the faults on. As for going to bottom floor, it is recalibrating its position. If you can determine the floor, check or change the lock beak. I would check vane clearance also. Another common issue is the aux contacts on your main contactor. If you main contactor is the 130amp you may want to change it to the 220amp, to save future issues.

Is this controller a 411M or 411MMS? I agree on the position slip possibly being caused by an e-stop.

I do not think that a clipped door lock will cause your car to correct; normally, you will only have to run to a terminal when you lose position.

I would check your inductors, wiring and vane to inductor clearances. Checking the encoder is a good idea.

it is a mod, not sure of the differnce between 411m and MMS, there were a few items this weekend relating to pr input errors. pr sensor error or something to that effect. per the mechanic that took the call this weekend. looked at some 411 prints, and can't find any pr sensors on the prints i have. i will probably be out there this week and will check what you guys have indicated. thanks for the input will keep you posted

411MMS has an MLB3 board with a four character display that shows faults and car status and is in a two door cabinet

411M has no display, and is usally in a tall cabinet with a front door and back door.

Ok its a 411mms. Also found pr inputs. In parrallel with lu and ld signals
Getting intermittent 2831 and 2832 errors. Both pointing to replacement of mlb3
Board.

well did some playing with unit today, cleared all faults, gave it a long run and opened the door lock circuit, the car logged 5 errors, none of them were the faults that have been being recorded. the car stopped, and then continued down to next floor, and was happy, so know that clipping lock will not make it want to reinitialize its position. only log a dfc/dcl/bypass fault if the door close and lock does not make, then it would log the 2812. thinking maybe i have a bad mlb3 board, not sure, i was running car, and never saw any issues, but when i checked fault log, it had logged a 2832 fault, did not shut the car down, guess its time to start throwing parts at it. can't get it to log the 2831 fault while I'm watching it, so maybe that fault will shut it down, .

I had a Otis 311 that done something similar to that but only done it on more than a 6 floor run changed encoder and it works fine

This is a little out in left field? If your at the site with another person, what if you watched the PLR count and with the handle of a screwdriver tap lightly on any encoders, selectors or anything else you can try?

Definitely check you haven't got a broken spring buffer on any encoders. While it may not be displaced, it could flip or speed hump the count and get out of +/- of the error on the ideal shaft count.

thanks guys, after some further inquiries, i was told that the positioning system does not rely on just the encoder only, from what I'm understanding, i believe that as the car runs and passes thru the lu and ld sensor, when both lu and ld are on, a snapshot of the current position count is compared to the stored floor count. If these 2 counts are not equal within a certain count, then the car will do an emergency stop and after that i was told it may do a initialization run, or it may do a correction run, not totally sure which. however, we may be onto something, as the last call was 3 days ago, at which time i had the mechanic check the cab for any side motion, cab steadiers were ok, but he indicated that the roller guides were out of adjustment, and almost scraping rail on one side, he adjusted the roller guides. I figured it would be back, so i went out the following day and ran the car all day with no failures, so now after learning the above info, I'm wondering if maybe the sensors were getting out of the vanes and causing trouble.
could be just a coincidence that the car has not come in yet, we will see. will keep you posted. thanks sinister1, for the input on checking vane clearances

..sometimes all it takes is a little adjustment on any of the floor vanes which operate the sensors..followed bt a new learn run..goes a long way..