Home Forums General Discussion Technical Questions Dover DMC

I've got a DMC thats cycling it's doors at the 1st and 3rd floor. HW relays pick and DCL goes high then the door immediately opens. The door hits DOL then starts closing again. It has the old blue door board. This car has hoistway mounted directional and slowdown swithces, no selector. EE and SE are staying high. If I give it a car call it will leave the floor. I've seen it do it at the top and bottom floor but not at the intermediate floor. It is a 3-stop front only. The blue door board has an extra band with magnet on it I think for center of travel. I'm leaning towards a bad board but it doesn't do it at the 2nd landing.

If you’re sure that the locks are good, then the hw relays could be bad. They convert the 150v to give a signal through the travel cord back to the signal on the clc. I’ve had the relays, power board, and clc all fail. I guess I’d check the he signal at clc and see if that signal is staying solid.

I’m sorry, reading my previous post the 150v picks the hw relays and their contacts give a low voltage signal to the clc. Also I’ve had clutch clearance issues giving trouble on different floors.

I’ve had similar problems with DMCs, the first one was a cracked cam/magnet holder in the operator, the second time was a bad door lock, but intermittently, I know those Dover door hook contacts can become cracked or have a wobble to them because the hole where the roll pin goes it starts to oval out, I’ve also seen them brake and the car will take off with the doors open, so be careful

Check for low voltage on p150. Newer door boards block the capacitor that filters the p150. May need to add one in controller.

Install a 68mfd, 350V capacitor assembly on to the Power Unit Relay Card. Connect the positive Red wire to P150 (T3-7 or T3-8). Connect the negative Black wire to G150 (T3-5 or T3-6).

door lock at 1 and 3
can't be on dcl and have lock open
lock seen open or actually is open