This is an old lift. Has developed a new problem. In our 35yrs of servicing it, it has never been reocrded on our logs. Or any of our other similar age elevators. Here is the problem.
Down direction only. When called to the 1st landing either by 1C or 1U. The elevator will respond but never goes into high speed. Not a weak coil or shot coil because it works just fine in the up. Tests show no voltage/current flow happening across coil so it is not even trying to come in. This is issue 1.
Issue 2. When it finally gets down to 1st landing it stops about 5ft above the floor on its own. Kicking out all the run relays. But never the call relay. Generator times out and it shuts down. You then give it a call to any of the upper floors and it fires up answers those calls but because of the still latched 1C or 1U it trys to return to 1st landing. And is stuck again. The elevator stops at all other floors just fine , albeit slow in the down direction, except the 1st floor. It won't even run down to floor level on inspection.
The selector is a piano string drum, screw gear vertical carriage with ski's and buttons. I have checked all the ski's and buttons and toned the wiring. All ok.
Have checked top and bottom Hoistway switches. Ok
Have checked leveling switches. Ok
Have checked the car top LU DZ LD old ass giant MAG switches. Ok.
Motor and generator brushes all good. Armature clean copper on both.
Old original resistors, caps, shunts, TR black boxes and relays.
Vintage type that it has the analog voltage meter built into the black asbestos control panel. Sitting IDLE at 120vdc dropping under relay demands and load to around 90vdc..
I have been speculating that Otis coils have a way of causing a voltage drop without actually burning up. Like the older the coil it now needs 130v to work vs the original 110v. Anyway that is side note.
I am running out of ideas. Anyone? I just feel I am missing something.