MCE / GAL DOOR PROBLEM

Hello folks. New member to site & from what I've seen so far it's really very good. Here's my problem and I'd love your feedback;

Elevator approaches terminal landing, slowdown and level are ok. It begins door opening cycle (no pre door). Car door open's at full speed, stops at halfway point in the opening cycle, and then reverses to a full speed close cycle (scanner edge is positively ineffective). The door then closes fully.

Job particulars: 11 story passenger elevator. 2001-2002 vintage MCE IMC-MG controller with an associated GAL MODL operator (single speed, horizontal slide. opens to left standing inside the elevator). Tritronics scanner edge.

I have not seen this happen but two trusted, intelligent people in the building have. I have my thoughts but don't want to contaminate the thought process. So what do you guys think? Any input is appreciated.

That's something I would really want to watch in the m/r, while it's happening. I would watch the state of DOL during the open cycle, for that ends the open cycle. I'd watch all the door flags, ie, DOI, "door open intent, dol, dcl, check and change associated triacs, dc and do relays, stuff like that. Done any of this yet? Where are you working?

Working just outside the Tampa area Vic. Very intermittent. I'm going to jump into the GAL operator cam assemblies. I'm thinking I may have a bad cam assembly contact block and/or it's shifting. If I lost the physical DOL circuit during opening that would cause DO relay to drop. Also, if DCL, in same cam assembly housing is defective the edge would be rendered inoperative because the controller would think the doors are already closed and then the edge is out of circuit. The non operative edge in the closing cycle is certainly a clue, although I'm not sure what that clue is telling me yet. Thanks for the input.

Did you verify nudging is operating? Will the door reopen by the safety edge when in nudging? Has it happened at intermediate floor? I'm with Vic check your triacs. Try running the car from the controller. See if the door zone or door relays are malfunctioning (chattering, dropping out too soon or not picking up). Is the machine room very humid and or dusty (motor generator)? Any carbon buildup on the controller?

Had a very similar problem with a Tac 50. Apples & oranges I know. But it did the same thing You describe, only at the top two floors, (14 stops). The problem with that one was the brake wouldn't drop fast enough as the doors were opening, the car would do a emergency re-level closing the doors immediately. Some old fashioned PM on the brake and that was that.

i think the edge not working is the clue to work on, what would keep the edge from activating? I would think that the car does not think it is in the door zone, or as galaxy points out, maybe it is doing a slight relevel, and since you have no pre opening, that is shutting of the door open circuit. what ever the problem is, if you are lucky, you could monitor the DOI flag as vic has said, and catch it going off, but if it is really intermittent, that could prove to be a little tedious. why don't you try forcing the car to do a relevel as the doors are opening, and see what happens, also maybe simulate a loss of door zone as the doors are opening to see if you can simulate the problem. I would think if the door open limit failed at the halfway point, then the door would stop, and the door timer would begin, then it would close as normal. as far as the door close limit being open, causing the detector edge to become inoperative, i would test this. simulate a detector edge input when the doors are fully closed to see if they will open. some cars will open the doors if you break that beam when the doors are close. we used to open some doors by sliding a piece of paper in the door to block the edge, to get it to open at secure floors, where a pick was not working. good luck sounds like a good one

Scott and Galaxy could be on to something with respect to loss of a door zone input. Another thing that would cause that could be if your tape guides are excessively worn, When the doors start to open the cab shifts just enough to lose the DZ reed switch. I have seen the top floor affected more if the tape is not plumb from top to bottom since it tends to be tighter to one side as the car gets to the top floor.

Yeah, Scott, I think you're right about the DOL probably not being "it", because there's no door time. I was thinking that too, but you gotta start somewhere...

But if the door zone went low, then the doors would shut right away, w/o pausing for door time.

Does this job have vanes and mag switches for door zone, or a tape reader? Once I saw a car with vanes, where when the doors were opening, the car doors shifted enough weight from one side to the other, that the cab moved away from the vane, and door zone would dissapear during the door cycle.

I second the DZ input going low. Tape guides most likely the culprit. I have seen a bad ribbon cable from the relay board to cpu board... C2 or C1 don't remember but it created a similar problem.

Thanks for all the input guys. The door failure occurred only twice within fifteen minutes of each other and hasn't happened again in the past 12 days. We never saw it occur. I had the route mechanic replace the tape guides and go over cam assemblies. Nothing obvious. If it re-occurs and we nail it I'll post the results. thanks again for your help.

Okay. Time to back up. If it was a DCL fault/problem, the MCE controller would shut down due to a fault (no DPM input).

So; why does the door open half-way, then immediately close without effect from the detector or door open button? No door zone input!

The MCE LQUT and L(something) are notorious for having poor hall-effect sensors. Mostly, they are just loose. They require tightening or replacing. Also, the factory wiring on the landing systems leaves something to be desired. Check for wires that are crimped on the insulation.

First, though, I should ensure that the rascal is not flopping in the breeze. If the triac goes, the fault would be consistent.

Hope this helps. Schindler, Toronto, Canada.

Eleisha,
What was the answer to this problem?

it needs a MOD and get rid of the MCE/GAL garbage.

just saw the post i had the exact same car setup/vintage mod do this. mine had the vane readers, no tape and it ended up being a sluggish HW drum brake which causes a crazy relevel and the doors to close. check your brake, lu, ld dead zone and your profile speeds. another sign of this on that mce junk is your car direction gongs going off more than once.

are otis controls the only one that actually stops the car electrically before dropping the brake?

[quote=GreenPants
are otis controls the only one that actually stops the car electrically before dropping the brake?[/quote]

It doesn't sound like you are kidding...

The only traction elevators I know of that stopped on the brake were the old ac units from long ago. I don't know of any modern manufacturer that stops on the brake. Some have timers that must be adjusted, to ensure the brake is set before the drive turns off. The release of brake switch may trigger the shutdown of the drive, but I'm not familiar with everything on the planet, so others may chime in here.

Your right on that one Vic-pretty much everybody for the last 30 years has electrically stopped the car before the brake sets. One of the big problems with mod is the addition of a brake switch to an old, worn out brake.

i just see a lot of newer controls that slow down to 3 or 4 fpm then set the brake, like this '01 vintage mce stuff. im not sure if it was just never adjusted right or what. looking at the way the profiles are generated it never seems to stop completely and hold while the brake sets. seen it on brand new trx5's and tac50's that we picked up. of course brake timing becomes an issue shortly after install. i agree with the brake switch issue on old brakes that can be a hard one to adj.

Most brake timing happens way too fast for my liking! I like a nice "Japanese" profile. Your probably right in the fact that this stuff is not getting the attention it needs How bout those US 1200 units that dont set the brake while loading and unloading

The old Westinghouse Epoch 1's releveled with the brake set...

I don't know of any 1200's that haven't been modded, but I remember them. Load weighing had to be spot on...Every one of those old single or dual speed AC's I've seen stopped on the brake, and a lot of the old Otis relay stuff had a brake "Relaxing" circuit, for the final leveling...

The UMV and MRS units have a soft brake relevel which is a really nice idea.

might try selling the customer a closed loop gal operator they are pretty good equipment..we currently use them on our mods and they are easy to set-up and maintain...

Vintage MCE stuff can be made to stop just fine. The problem is that most guys don't know how to properly set up the regulator( Black Box) or don't have access to a scope. If you ever read MCE's setup procedures it will state [ For professional results an oscilloscope must be used]. But having worked for a few companies that were too cheap to get one, I understand the dilemma faced by guys in the field. You do the best you can with what you have. If ES (electric stop) is set too far clockwise it can cause a continuous rocking in and out of the floor. The Current feedback circuit when set properly allows the car to hold zero speed. One of the constant failure in older MCEs are the crappy little Aromat relays used in the speed selection circuits. There have been many good ideas presented here and I do recommend verifying the HW brake is set properly even if it means tearing it down, cleaning, de-glazing the shoes, and lubricating all pins.