Home Forums General Discussion Technical Questions Door issue with MCE

I'm having an issue with an MCE HMC-1000 with a GAL MOD operator. Customer was complaining of doors cycling every now and again. Finally witnessed it yesterday, I saw the doors close but the door lock LED on the controller wasn't lit. I figured it was just a simple adjustment of my limit since it was reported at all floors. Upon investigstion I saw the door would stop dead just before DCL would break, leaving my door rollers picked. My DC relay drops out, as soon as the car gets a demand holding torque takes over and car runs fine. RD1 and RD2 check out. My limit adjustments on the door are fine. I did try to increase the door torque a little to see if that would change anything, but that's sort of pointless since DC relay drops out anyway. I did check all contacts on door op and cleaned. Didn't have a lot of time to go much further. Just wondering if anyone has any other suggestions. I was thinking I could speed up closing speed to get it to slide in, but I'd rather cure the issue than mask it. Thanks

Check all the belt tensions.. Just did an upgrade and thought all belts were good. I just gave the belts alittle more tension and it made all the difference in the world! Check the chain also!

verify with a meter the state of you DCL. A lot of times as the cam/nylon pin are close to dropping, the wiping of the contact can "break" your DCL signal.

I agree with verifying w/my meter on my DCL, I haven't done that yet. On the other hand I did set the DCL so it would not break even whent the door was fully closed mechanically, and it still died.

have you changed the nylon pins that ride on the cam. somtimes if those are flat you will get intermitant door cycling, or dcl dropping to early.

I agree with Take the Stairs. GAL limit cams have nylon pins which wear flat with age. This causes the snap contact to become unreliable.

Upanddown
I think that when there is no call in. And the doors close. The hatch door interlock pickup roller is contacting your car door clutch. Not allowing the keeper to drop the doors will recycle until it shows the lock made.

Take a look at the clutch and the pickup roller from the car top.

I have same kind of problem before.
The clutch roller is sticking into the clutch too much and the clutch is not releasing the roller at the end.
Also one time, I have a dead spot on the door operator motor. The door stop @ the same spot every times.
Hope this help.

I agree with all of these suggestions. hopfully one works goodluck.

GAL has 2 sizes for the cam nylons. Make sure you have both sizes before you take the assembly apart

is short clutch not retracting before the door mechanically stops?

Haven't gotten back there yet to check again. The pickup rollers are still picked by the clutch, therefore not making the lock up causing doors to cycle. This is due to the doors not closing fully, because I'm losing DC relay to soon, even before DCL breaks. Not sure if I'm losing it on my final slow closing speed or what. Thanks for all the suggestions.

so let me get the correct picture...Your door close relay drops out before your door close limit breaks? Are you losing the normally closed contact on the DO relay? Or the door stops before the DCL breaks. The resistor for the close speed is very fragile with thin wire and breaks easily. Possibly it opens up when it heats up.

Correct, DOL seems good visually. Again I was there doing other work and picked up on this after customer mentioned it so didn't have much time. When I go back I'l be probing with the meter a bit more to see what's up. I did check the resistor in the door operator for any breaks, along with RD1 and RD2 in the controller. All seemed good. One more thing I remembered, if it sits at the fllor with no demand and the door is in the state which I've been describing. If I hit the reset button on controller or cycle power, upon power up it does close the door to fully closed. So it seems that it's looking for DCL. I hope that doesn't confuse anyone. Again, thanks for all the suggestions it's much appreciated.

timer or high resistance in series with the dc relay?

Watch the Door Close bit in internal memory, during the close cycle. Compare it to the DLK LED on the processor board.

IF the DC bit goes low, before the DLK led lights up, then the processor is ceasing the close function, probably because that's the way it interprets the inputs it's receiving, one of which, (one of many), is the Door Close Limit.

On the other hand, if the DC bit stays high, yet the DKL led stays low, then the processor still wants to close the doors, but it's intentions aren't amking it to the DC coil, and in between there could be an issue.

(Hope that doesn't sound too vague)

Also watch the DCL bit in internal memory. Betcha it's going low!

If my memory serves me right,on that vintage MCE there are two triacs involved in the close ckt. One is DCP door close power and the other is DCF door close function. Make sure both work. The other possibility which I don't think you have on your vintage is a DPM timing problem. Newer jobs use an additional input called DPM (door position monitor) which makes about two inches before the door closes, then you pick up your gate sw and last the DCL limit opens. DPM must be set to make prior to both the above or you get sequence problems. I guess you checked the retracting roller on the GAL clutch for flat spots? The limit flags are easy to watch using the diagnostic dip switches on the swing panel. The only one that can be tricky to find is DPM which you probably are not using on that vintage unit.