Home Forums General Discussion Technical Questions DMC brown out

over the last 6 months i have taken 2 OT calls at this old folks home that gets occasional brown outs or quick power failures. this unit doesn't have the dover UPS backup on it and we have tried to sell it to them but they wont buy it. the car shuts down and won't open the doors for a hall call. i get on the car top and do the selector board learn run a few times because i can never remember the sequence then the car run normally. i was wondering if there is a way to get a DMC to do a learn run on its own or if this is just something they have to live with until they buy a UPS. BTW i don't carry a DMC tool with me because i dont have any on my own route and this is the only way i know of to get it to go back into service.

Inside the COP there is a batteryback up. May I suggest you replace the round clock like battery and perhaps put a back up battery on it. I remembers the parameters.

Respectfully Submitted,

Robert L Krieger Jr.

it got a new CLC battery after this happened the first time thinking it could have been bad.

Hey there GreenPants... I admire alot of your posts and Im guessing you work for Otis, ha ha- maybe try their new social site or call ROLE....

its a customer issue and it has only happened once every three months so im not too worried about it. i was just curious. my problem is i only have otis equipment on my route and i have forgotten a lot from my repair days. sometimes i miss the challenge of shooting trouble on brand x stuff.

The older batteries were thicker than the new ones you can buy today. At least this was my experience. Although the battery # was identical, their thickness definitely was not. Both were made by a major manufacturer, too, no "off-brand" crap. The thinner cross-section was not clamped tight by the battery contact finger, which made the new battery jiggle around a bit in it's holder, and the car would dump its memory during a power failure. Ended up putting a little ferrule, snipped from a blue Sta-Con fork, over the battery contact finger. This made good contact, and that particular problem went away.

hey green pants, how are you doing a selector learn run? You can not do a learn run without a fast tool or world tool. If the battery were the problem, you would lose all parameters, and would have to reprogram the unit. if you suspect a loose battery holder, you can take a voltage reading at the D4 diodes anode side, it is just above the battery on the board, it should read greater than 2.5 volts if not, do not turn off power or you risk losing clc program. You may be having a selector fault, one way to check if your having a selector fault without the tool is to open selector cover and see if the little LED is off, if it is, you have a selector fault. you usually get a selector fault with bad tape guides, or a bad contact on the switch tree assembly. if you have to run it up and down a few times on inspection before it goes back in service, i would suspect a bad tree contact.

this only happens when they have a power outage of brown out. the CLC batt is ok like you said i doesnt loose its params. im not sure if its a fault or what but i have to get on the cartop and run it on insp to the bottom dir limit push the button on the selector board then run up the HW to the other limit then the light goes from solid to flashing. when i take it off insp the doors open and close real slow and it goes back into service. im not too worried about its only happened 2x in 6 months. it runs great the rest of the time.

thats strange, I have never seen that. You should be able to get on car top and push selector reset button and it should come back on without any movement. Like i said if the selector light is off then you definately had a selector fault. maybe the brown out is causing the selector to lose communication to the clc board. in any case you should be able to just cycle power to get the car back on line. If you run top to bottom on inspect, without the interface tool set to selector learn, then you are not learning the hoistway. however, when i do a selector learn with the tool, you do run to the bottom limit, push the reset button, the led comes on solid, then stays solid until you hit the top limit, if all is ok the led begins to flash. So it does seem as it is doing a learn trip, very interesting. maybe some dover guys have some input on this one. I have worked on quite a few dmc over the years and have never seen this. always something new to learn in the elevator trade.

the most commonly problems with automatic in DMC elevator DOVER
1.-The selector guides
2.-One magnet out of posicion (slowdown or floor magnet)
3.-the switch tree
4.-The reed switch in back selector board
5.-losse wires between clc connectors to selector connectors
6.-When the clc battery is dead and turn of the power supply the parameters is lost.

Note.-when the parameters is lost the elevator only move in inspection,but if you put in automatic the elevator go to learn first floor but in the first call the led in the selector board turn of because dont have data traveler in clc memory and not check the magnets to confirm.