Home Forums General Discussion Technical Questions DMC PRoblem

Ok I been working on this DMC for 2 days . The fire department came in and ripped the door open to get out a stick passenger . My two issues are .
1. When car is level with Lobby floor the car goes to take off in high speed . It gets about 3inches then blows the f1 fuse . Happened like four times . If you jump out the whole circuit and move it on inspection past the first floor it's fine .

2. When level with the second floor or third ect. The car goes into down leveling and shuts down in door zone . Car will not move at all .

Any help is much appreciated . This elevator is driving me bananas ...

First, is the fuse blowing problem constant? Does the car run normally from the second and third floor in the up direction? If it only blows at the first floor, how far up does it get? Does this car have a safety edge and eyes, or a light curtain? Fuse F1 controls the AC1 line. It is 120VAC. Other than the solenoids, the power supply in the COP, and the switch tree, the only other place AC! should go on the car is the eyes or light curtain supply. If you have eyes, I would look at the cord to the eyes. The firemen may have damaged the cord and it is hitting something and shorting the AC1 supply. You could put a new fuse in the unit and run it up in normal operation, let the fuse blow and check all the high voltage terminals to see where your ground or short is located.
Second, Does the car leave the floor normally above the bottom floor in the down direction? When the car shuts down in door zone, what do you do to make it move again? Why does it stop? If you are manually lowering it. stop and find the reason for it not moving. Is this a DMC1 or a DMC1A? With enough information, I'm sure we can fix this turkey.

DMC 1 . It only blows the 3amp f1 fuse when it's level in the lobby . It goes to take off on high speed and goes about three inches . Then boom ! If we jump out the whole circuit on slow speed we can get it to the 2nd floor an then the car just shuts down . It gets stuck with the dz relay and down leveling relay ingaged . Then if it isn't in the DZ it will time out and lower back to the lobby . Maybe parking itself . Now if I go on top of the car and hold the top limit in an move it on inspection it moves three inches also .

Could it have anything to do with door locks ? Maybe when they ripped apart the door it caused a short ?

Also I'm not picking up the high speed relay . When it does go to take off the relay don't engage at all .

Door locks are 150vdc and under a different fuse. With the fuse blown, are any of the 120vac terminals grounded? Do you have a print? Do you need a list of terminals to check? What are you disconnecting and where are you jumping to get it to move on slow speed? If dz and down level are energized, are the DN1 and DN2 relays in and does the down slow solenoid have power? When the car moves to find itself, the high speed relay doesn't come in. You said that the car only blows the fuse at floor level, and then you said that it takes off and goes about 3 inches.

Check your switch tree on the side of the car-some of the switches had solid wire on a moveable terminal.

LD,
Like E311 is saying, Take a look and watch when LU & LD pick & drops if it blows the fuse. Check your TSL switches. Watch your AC1 & AC2 voltages...

I have many DMC,s on my route..I agree with E311..majority of shutdowns I have encountered are those Hoistway Tree Limits..broken wires as well as broken springs.a real first class reliable product..

remember that switch tree can be unbolted and pulled up onto the car top for easy repair, don't try hanging upside down to troubleshoot you may miss the broken wire..

I Agree with everyone, switch-tree. I had a unit that would go in the up direction from bottom landing, about 4 feet, stop, and then come back down to bottom landing in levelling speed. I was perplexed, every once in a while, it would run ok. Found a Pinched wire shorting to ground on the cover of one of the switch tree switches. I love the DMC's. This is one of the very few flaws in that system in my opinion.

I also agree, DMCs are usually bullet proof. The TSL switch is the weakest link. I'd look there first. The only other problem I have with DMCs is the rectifiers on the main relay board, not all but some of them, they were soldered in which sucks.

What floor did the fire dept rip the door open on? It would make since you are having issues on the lobby level that they tore up the lobby level.

Although the switch tree is certainly problematic, from the symptoms, my money is on a solenoid being shorted or the wiring from the relay board to the solenoids being compromised.I don't think it is anything in the locks or doors since the fuse that is blowing is in the 120vac circuit and not in the 150vdc circuit. As for stopping before the floor, that may be either solenoids or contacts on the various relays. We have never been told whether the fuse blows as you take off or if it blows 3" above the floor. Also, we still don't know how he gets the car above the bottom floor to experience the problems at the second floor. Above the bottom floor and below the top floor, the switch tree only provides continuity for the valve circuitry. I believe that he has stated that the car seems to run almost normally between the floors. High speed does not come into play unless you are leaving the floor from actual floor level.

Was the car running fine until the fire dept came in? and What floor?

Firemen came in because it was stuck. Probably a blown fuse

Yeah I guess that was a stupid question I wanted to know was the fuse blown when you came in after the fire dept or did it blow once you tired to run it. I need to look at my prints and see whats all in that circuit. How does it run on inspection?

Dont know, I was trying to help the guy, but have gotten no answers. Right now everybody is just guessing. Read back to the beginning and you will know everything we know. I think LouieD has probably fixed it by now and just hasnt posted a resolution.

I would replace the DZR reed switch on the selector.