Otis door problem

Working on an Otis gama D or spec (not sure which) I have picture I can email. Door controller is big silver box with Contacts O1thru O7 and C1 thru C7 ....The door open is intermittently hesitating a few inches into the open. I have cleaned all the open contacts thoughrouly. Still having same problem. Any advice on where to start with this controller.

Sounds like a QL operator. I would make sure you aren't momentarily losing your DZ signal. Not sure about Spec 60, but Gamma D uses a narrow tape; worn guides can make this happen.

Yea that makes sense. I had that once with a swift . I will check the selector out when I get back there.

I've seen something similar on 2 QL operators caused by a brake in the resistor wire under the tap. Both times it was the same resistor, back right corner if you're looking from on the car.

I would suggest checking the resistors and contacts for breaks of wire or connections, in the area/contacts where it starts to fail, although its a good idea to check the whole lot. Check the continuity whilst wobbling wires about. It could also be having a high resistance under load conditions.

I have a setup procedure for QL operators . Pm me if you want it , worn bearings on the small A frame that holds the cam rod can cause intermitant making and braking of the switches . Any excessive wobble will give you problems

Txs for all your advice. I went over everything thoroughly and the problem immediately stopped. However it started happening again. Lol. Does any one have advice on an upgrade for this operator ?

Have you looked at the open and close relays/contactors in the controller? Whether these are the black Arrowmat or the white Sprecher, they will aventually give intermittent problems like this.

If the problem went away after touching everything I would mark and pull every resistor tap. There's probably a broken wire under one.