Thank you so much for your insights Johnny!

1) Context on the restoration project:

Unfortunately I got involved in this restoration project too late in the game to provide a full record of what exactly has been done to each and every part of the elevator. But I'll provide as much information as I have.

The elevator was renovated out of its previous location, and the current owner had the opportunity to salvage it, move it to its new location, and is working to restore it.

A full service elevator company was involved in the installation and adjustment of the lift cables.


2) More details on the motor:

The service elevator company took the motor to an electric motor shop to be rebuilt. As I mentioned in the previous post, the electric motor shop said they rebuild the motor stator exactly as it was when they received it.

The motor has 4 stator coils numbered 1 through 8.
- Stator coils 1-5 and 7-3 have the same phase and are connected in series making coil 1-3 (wires 5 and 7 are shorted).
- Stator coils 4-8 and 6-2 have the same phase and are connected in series making coil 4-2 (wires 8 and 6 are shorted).

I used an ohm meter and and RLC meter to measure each individual stator winding, and each series pair.
- From the ohm measurements it looks like all windings are identical (except for the phase shift between coil pairs).
- Each individual coil measures 1.68 Ohm +/-0.5% DC resistance and 9.8 mH inductance. The inductance was measured at 100 Hz (lowest setting of the RLC meter).
- When each stator coil pair is connected in series, the DC resistance increases by a factor of 2 and the inductance increases by a factor of 3.5. I was expecting the inductance to increase by a factor of 4 given the inductance increases with the square of the number of turns. I attributed the discrepancy to the fact that the stator IS NOT an ideal inductor.

I also used the ohm meter to verify that all coils are insulated from each other (i.e. there are no shorts).

- To verify that the stator coils were paired correctly I used an oscilloscope to compare the phase and polarity of the voltage signal produced at each stator coil when turning the motor shaft manually.
- To verify that the stator had six poles I used an oscilloscope and an optical tachometer width a digital output to verify that each motor shaft revolution produced 3 cycles across each coil.
- I also verified that the different stator coil pairs produced signals with 90 degrees of phase shift between them.

It looks like the motor was rebuilt to support 110 V or 220 V operation, with the coil pairs connected in parallel for 110 V operation and connected in series for 220 V operation.
- The dual voltage wiring options make me wonder if the motor has been rebuilt more than once and at some point.
- The original specifications plate on the motor does not indicate the dual voltage operation.

MOTOR SPECIFICATIONS PLATE

These are the connections between the controller and the motor:
- MOTOR 1-2 on the controller is connected to STATOR COIL 1-3 on the motor (MOTOR 1 is connected to COIL 1 and MOTOR 2 is connected to COIL 3).
- MOTOR 3-4 on the controller is connected to STATOR COIL 4-2 on the motor (MOTOR 3 is connected to COIL 4 and MOTOR 4 is connected to COIL 2).

When I first started debugging the controller the MOTOR 3-4 connection was reversed, which resulted in relays A and B moving the elevator in the opposite direction called by the schematic.
- Per the schematic RELAY A moves the elevator UP.
- Per the schematic RELAY B moves the elevator DOWN.

Per your recommendation I'll try the following connections:
- MOTOR 1-2 on the controller connected to STATOR COIL 4-2 on the motor.
- MOTOR 3-4 on the controller connected to STATOR COIL 1-3 on the motor.
- This modification will effectively change the main and auxiliary stator coils.
- It's possible I'll have to reverse one of the stator coils polarity to get the direction of the elevator to match the controller.


3) More details on the controller connections and debugging:

When the elevator was removed from the previous locations there was some work done to document the wiring of the up/down limit switches, final limit switches, door lock contacts, door contacts, hall and car buttons, etc., but the documentation was incomplete and might've introduced some errors.
- The wiring on the new location used this document to wire everything to the controller.

The elevator service company was able to get the motor running up and down by manually engaging the controller relays, but couldn't figure out why the button calls wouldn't do anything.
- The elevator company got the schematics on the original post directly from OTIS.

3.1) Call buttons debugging:
- With the schematics in hand and an ohm meter I tracked an open circuit (loose hex nut) on the wiring on the back of the controller that explained why the call buttons were not working.

3.2) Elevator gate and final limit switches wiring correction:
- From net 36 to net 39 all elements must be wired in series so that if either of the elements is an open circuit the elevator does not start.
- Depending on the position of the final limit switches, net 36 to net 39 were shorted even when the elevator gate was open. One of the final limit switches was connected in parallel with the elevator gate.
- This wiring error was corrected so that if either of the (1) final limit switch below the down limit switch, (2) final limit switch above the up limit switch or the (3) elevator gate is an open circuit the controller ignores all calls and the motor is stopped if running.

3.3) Door lock contacts:
- As indicated in the original post this switch is currently not being used.

3.4) Limit switch on car:
- As indicated in the original post this switch is currently not being used.

3.5) Door interlock implementation:
- Per items 3.3) and 3.4) net 41 to net 33 is an open circuit.
- The connection from nets 32 to net 33 goes through the OTIS "L" Door Contact located on the door of each floor.
- The door contacts on the door of each floor are connected in SERIES.
- If either door of each floor is open the controller ignores all calls and the motor is stopped if running.
- The door interlock function has been tested with the motor running (the motor stops) and the controller ignores all calls if either door is open.


4) More details on door locks and door interlock function:

With the information you provided on the LIMIT SWT ON CAR that closes when the elevator is close to either floor landing, and the door lock contact that closes only when the door lock successfully engages, I'll think about how to incorporate these elements into the door interlock function of the controller.
- My only worry on this part of the schematic is that the path that connects net 32 to net 33 on the schematic has two parallel paths: one through the DOOR INTERLOCK CONTACTS, and a second through the LIMIT SWT ON CAR and the DOOR SEQ. CONTACTS. Parallel paths mean a logic OR function, which means that the DOOR INTERLOCK CONTACTS could be open, but if the elevator is close to the floor an alternative path is created that would allow the elevator to continue moving, or accept calls.

The elevator doors at each floor do not have the door lock release chain you describe. Even though this introduces a way to defeat the door lock it sounds very helpful for servicing the elevator, or as way to get out of the elevator if the door lock release wheel loosens and leaves an elevator passenger trapped at the destination floor.
- If the door is locked the only way to open the door is for the elevator car to release the locking mechanism (or to remove power to the elevator controller, access the elevator shaft and use a sick to manually release the door lock on the first floor, or a very long stick to release the door lock on the second floor).


5) More details on UP/DOWN limit switches and final limit switches:

The following images show the limit switches on the second floor:

2ND FLOOR LIMIT SWITCHES
LIMIT SWITCHES RAILS ON CAR

Both limit switches are double pole single throw (DPST) switches; however, they are both operated as single pole single throw (SPST) switches.
- The picture shows the limit switches on the closed position.
- The lower of the two limit switches on the picture is labeled UP LIMIT SWITCH on the schematic, it connects net 43 to net 34, and indicates that the elevator car has reached the second floor.
- When the elevator car reaches the second floor the lower rail on elevator car will move the UP LIMIT SWITCH to the open position, removing power to the C, A and T coils that latched the elevator call to the second floor, which in turn remove power to the motor and engage the motor break.
- When the elevator car is in the second floor because the UP LIMIT SWITCH remains in the open position the controller will ignore calls to the second floor.
- As the elevator car leaves the second floor (heading to the first floor) the lower rail on elevator car will return the UP LIMIT SWITCH to the close position.
- On the event that the UP LIMIT SWITCH does not open when the elevator reaches the second floor (i.e. switch fails short), the FINAL LIMIT SWITCH above it will be pushed open by the upper rail on the elevator car. If this happens the controller will ignore future calls as the FINAL LIMIT SWITCH opens net 30 to net 39. The idea of preventing calls to the first floor was probably to have the elevator serviced if this condition ever happen. The fault would indicate that the UP LIMIT SWITCH did not open (failed short), or that the motor break is not stopping the motor fast enough.