We have a 23 stop building with an E311 Duplex. Each floor is secured because the elevators open right into the homeowner's living room. The building is complaining that the elevators will occasionally open on random floors without being called from the hall station or car call. All car and Hall calls are serial linked. We have changed the boards in the car and boards in the hall from floors that have complained. The home owners are complaining that the problem still persists intermittently and have been there since new construction. All of the wiring and line termination boards have been gone through and verified good. Any ideas on what could be causing this issue?

hey admin. are the tenants saying that during travel the lift will stop without the car or landings being pushed? if so get the tenants to see if there are any common levels that it always stops on. it could be at these levels that the serial connections are faulty. also if it seems randon that it could be that the lift is losing its fast speed input to the drive it might just do a auto slowdown and stop where it can.also i take it has 2 lifts in the building? if so arent there a control pcb in the cop for the buttons to be encoded. if so change that pcb between lifts and see how you go.are they saying also that both lifts have the same fault?if so maybe the lifts are doing a zone transfer but opening doors when they shouldnt. maybe program the lifts to return the grd floor. just spitballing here.

"...problem has been there since new construction..." u say. If u've been to the building do the lifts rest or are the ghost calls keepin the lifts moving constantly?

first, what year was the job installed? second, are there any OCSS faults? third, how are the floors secured? (card readers or secure access) forth, how pissed was the otis guy when they left the building for the last time?

Does the ghost call issue happen at any regular times, or known hour of the day?Is there any readout, log, whtvr, that shows where and when calls were placed? Can you disable the calls, and see if the lift still opens on floors? Maybe it's not answering calls at all, and the I/R edge is flakey, generating an open command on a parked car?

The building is only 3 or 4 years old. The ghost call is very intermittent, it happens maybe once or twice a month. The same few home owners are complaining but all the boards on their floors and near floors have been changed and wires have been verified good. The floors are secured by card reader access and the security signals are sent to the Otis security interface board from the security company's relay boards. I'm not sure if it's happening on other floors because some of the units are not occupied all the time. There have not been any OCSS faults that I'm aware of but I will have to confirm on that one. The elevators are zoned to have one car at the bottom landing ( Lobby) and one around mid hoistway. They do not run without receiving a demand and the floors that are getting ghost calls are not near the parking landings. I have verified by their cameras that the car call does not light up when the car is called to the floor on a ghost call and it does seem to make a specific call to that floor and not just on its way to some other car or hall call. As far as I know, the Otis guy wasn't too pissed to lose it. He probably has too many buildings on his route already, he probably through a party that night!

I had a strange complaint on s 311 gem. It took almost a year before we had enough info to fix the problem. the complaint was the car would stop at various floors and open the doors, it would also cancel the car call the people inside the car had previously placed. there were numerous calls on the problem with always the same outcome, ROA , no one could find any problem. finally after many calls, a tenant noticed that if he placed a call for the bottom landing, and the car stopped for another tenant, if he placed a call for the second landing, the car would start down the hoist way, and cancel both calls and stop at a random floor. with that info, we could duplicate the problem , if you placed a 1st and 2nd floors car call from anywhere in the upper floors of the building, the car would travel a few floors, and cancel both calls, and stop at the next floor. you would then have to place the calls again. it was a very strange call. we replaced all the remote serial boards, and the ring control board per otis engineering request. still the problem persisted ,if you placed both calls the car would still cancel the calls and stop at the next nearest floor. otis engineers were perplexed, and could not find a reason for our problem. we ended up replacing all of the buttons, the serial link travel cable, power supply , you name it we replaced it. still the problem persisted. I started checking out the serial link for the car, monitoring the frequency with my meter, I can't recall the exact measurement, but when both car calls were placed, and the car started to move, the frequency would drop really low, and the problem would occur. I then started to work my way along the car serial link, isolating it one component at a time. It turns out that there were remote serial boards in the car top box that were there for card reader inputs, they were not being used at the current time. even though the boards had been replaced earlier during the mass board swap out, and the inputs had been turned off , just unplugging them solved the problem. there is still no resolution as to why this problem occurs, if you hook up the boards, the problem will occur again. all of the equipment has been changed, and the problem will occur again, sounds like you may have one of these strange problems that will take a while to fix.

The frequency is 1.2khz for Otis. Swift/TKE use 2 khz.

do both lifts go to each floor?i ask this as if both do this fault is it more likely that the fault lies within the landing call system. i also cant remember about the 311's but i know of others that are serial controlled that if your bus system resistors are off then you have endless problems with the communication between car and controller.

duplicate addressed RS boards, 0 addressed RS boards and the bad german RS boards from 2002-2003 can cause this among other things. check for HBP mode in OCSS.

Look at the serial link with an oscilloscope. Might find something weird.

Thanks everyone for all the great suggestions. I will look into these ideas and hopefully fix this problem.

forgot to mention dip switches on RS boards that are not fully on or off or water damage.

I have a fault just like that check all your connections for corosion and all the plugs on the landings and in the control panel have just copper and no insulation in the plugs also check your neg (-) is not going to earth also make sure your bus can line is at least 300mm away from 110v safty lines or 240 volt lines in the lift shaft

Hope this is of some help to curing the fault