Home Forums General Discussion Technical Questions Otis dispatching problem

Have a 2 car duplex with Otis pie plates selectors.
When both cars are at home landing car 2 will not take a car call until car 1 takes off.
So if I go into car 2 and place a car call it will not move.
I then go to car 1 and place car call. Car 1 will run and then car 2 will move to placed call. Also car 2 Will always run to 4th floor in up direction before homing. It's old Otis pie plate with advancer and floor bar.
Any ideas?

Need a wiring Diagram number from Data Tag on Controller and Controller Type from same tag.

I believe it's a 80 usl

80UAL

If it is a Duplex it will have a TT relay (Transfer Time). If no TT it is a 2 car Group. If it is a Duplex look at HJG relay (Higher Demand for Hall) and there should be a HLR contact in there that can hold car. (HLR is home landing relay in at lobby). If it's a 2 car group it will use a Selected Car System which allows only one car to dispatch from lobby for a period of time unless loaded. The SC system only allows one hall lantern to light for the next car being dispatched.

Sorry it's a 69&79 ual

Sorry it's a 69&79 ual 2 car group also car Chase's the up call so if I put Inn a second floor car call it will go to two then it will go to the third floor and then back down and it does this for each floor in the up direction.

In the twin jobs i have worked on, the cars when parked on the home floor would only have 1 set of doors open, and the other car parks with the doors closed. This prevents passengers using the wrong car, and sets the 'next car' preference. Also you note that car 2 goes to floor 4 and then another goes to the 3rd floor. This may be a contact issue, but i also did a general clean of the floor bars and the advancer panel, so if there is any tracking due to carbon dust, we can eliminate this potential problem. I made sure i wore a rubber glove and used a rag, just in case there is any back feeds from other controllers, and the system controller relays on the main selector like the VIP 260. Once this is done, and the faults are still there, then your going to have to track how your getting direction to continue up, maybe FH contacts potentially. Cant remember the circuits of my head, but would look there as a start.

It sounds like a 2 car group with 2 terminal dispatch that someone has locked on up peak to keep car at lobby and prevent cruising the shaft all day long.