Hope everyone that lands on this thread enjoys going over these old schematics as much as I have. I'm a hardware engineer by trade, but will take any job that involves figuring out how to make something work, specially if that something uses technology that is 100 years old.

There are two schematics available for reference:
1) TYPE 6006A CONTROLLER - SCHEMATIC 1
2) TYPE 6006A CONTROLLER - SCHEMATIC 2

The elevator in question services 2 floors and it is controlled with a TYPE 6006A CONTROLLER
- The elevator controller uses relay logic to latch hall and car button calls.
- When the elevator is on the first floor, the controller ignores calls to the 1st floor. This happens because the down limit switch is open.
- When the elevator is on the second floor, the controller ignores calls to the 2nd floor. This happens because the up limit switch is open.
- Once the elevator is moving to a floor, it ignores calls to the opposite floor (e.g. while the elevator is heading to the 2nd floor the elevator will ignore any call to the 1st floor).
- The controller stops the motor when the up/down limit switch opens, which indicate the elevator car has reached the desired floor.
- The door on each floor has an OTIS "L" door contact and an OTIS "L" door lock.

1) OTIS "L" Door Contact


When the door is closed the door contact circuit is closed.

2) OTIS "L" Door Lock


When the elevator car IS NOT in the corresponding floor:
- The door lock prevents a closed door from being opened (and the person opening it falling onto the elevator shaft).
- The door lock contact circuit is closed.

When the elevator car IS in the corresponding floor:
- The door lock is disengaged, allowing to open the door in the corresponding floor.
- The door lock contact circuit is open.

The elevator safety circuits are wired in series to implement a logical AND function. If any of the following circuits is open the motor is stopped (if running) and all elevator calls are ignored:
- 1st floor door is open (OTIS "L" door contact). One of the door interlock contacts shown in the schematic. The door lock should prevent the door from being opened when the elevator IS NOT in the corresponding floor; however, the door can be opened shortly after the elevator starts moving and the door lock is still disengaged by the elevator car rail.
- 2nd floor door is open (OTIS "L" door contact). One of the door interlock contacts shown in the schematic. The door lock should prevent the door from being opened when the elevator IS NOT in the corresponding floor; however, the door can be opened shortly after the elevator starts moving and the door lock is still disengaged by the elevator car rail.
- elevator gate is open.
- emergency stop switch on elevator car is in the down position.
- final limit switch above up limit switch is open.
- final limit switch below down limit switch is open.

Two outstanding questions:
- The elevator car has a limit switch on car that is currently not being used.
- The door lock contact circuit is currently not being used.

1. The limit switch on car is normally open. The circuit only closes when the elevator car is close to the 1st floor landing or the 2nd floor landing.
2. The second schematic shows the limit switch on car (when used) should be used along with the door seq. contacts (when used).
3. The door lock contact is open when the elevator car is close to or at each floor landing.
4. The door lock contact is close when the elevator is in between floor landings.
5. The door contact is open when the door on each floor is open.
6. The door contact is closed when the door on each floor is closed.

Given the previous six statements, I thought the simplest way to implement a door interlock safety function was to use the OTIS "L" door contacts on each door connected in series.
- If either door is open the controller ignores all calls.
- If either door is open while the elevator is moving the motor is stopped, and all future calls are ignored until all doors are closed.

The two outstanding questions are:
Q1) Is there a safer way to implement the door interlock safety function? Can the door interlock contact and/or the limit switch on the car be used in any way to achieve this?
Q2) What is an example of the door seq. contacts (when used) shown in the schematic?

One outstanding issue:
- Motor struggles to bring the elevator car down (counterweights going up).

MOTOR GEARBOX

The motor has a plate with specifications:
- HP 1
- R.P.M. 1200
- VOLTS 220 (Vrms)
- P.H. 1 (phase)
- CYC 60 (Hz)
- AMPS 7 (Arms)

The start and run capacitors are part of the controller, as shown on the schematic.
- The controller uses relay logic to open the motor brake, apply the full line-to-line voltage to the motor (close the accelerator switch), and when to disengage the start capacitor.
- The brake and accelerator coils are driven by the main motor winding voltage (A, B and C main switches) before the accelerator switch (K switches). The accelerator switch has a piston that introduces a time delay that allows enough time for the motor brake to disengage before the full line-to-line voltage is applied to the motor.
- The start capacitor is switched in (H switch) when the main line switch (C auxiliary switch) is engaged.
- After the accelerator switches engage (K switches) and the motor starts rotating, the voltage on the auxiliary motor winding starts to increase. When the motor auxiliary winding voltage increases beyond the voltage set by the power resistor 1HR and the coil 1H make voltage, the start capacitor is latched off (1H switch applies power to 2H coil, which latches power to 2H coil through normally open 2H switch, and removes power from H coil through normally closed 2H switch, which in turn switches out the start capacitor H switch).

The controller has a metal box under it to hold the start and run capacitors.
- The capacitor box had 5 x 27 uF film capacitors.
- Two capacitors were connected in parallel to make the start capacitor (condenser C3 on schematic).
- Three capacitors were connected in parallel to make the run capacitor (condenser C2 on schematic).
- The total start capacitance is 135 uF.
- The total run capacitance is 81 uF.

The old capacitors were replaced with 30 uF 440 VAC film capacitors (SFS44T30J291B-00DU).
- The total start capacitance increased to 150 uF.
- The total run capacitance increased to 90 uF.

Dissipation Factor
- The old capacitors have a measured dissipation factor around 0.5%.
- The new capacitors have a measured dissipation factor around 0.05% (10 times better).

With 5 start capacitors (150uF) and 3 run capacitors (90 uF):
- The motor always starts on the way up and make it to the 2nd floor landing.
- The motor sometimes starts on the way down, but would stall most of the times. When the motor managed to start, it would struggle a lot, particularly close to the 1st floor landing.

With 5 start capacitors (150 uF) and 4 run capacitors (120 uF):
- The motor always starts on the way up and make it to the 2nd floor landing.
- The motor always starts on the way down and make it to the 1st floor landing; however, the motor still struggles a lot, particularly close to the 1st floor landing.

The following links show measurements for voltage, current, power and rotational speed taken while the elevator is going up (white traces) and going down (red traces):
VOLTAGE MEASUREMENT
CURRENT MEASUREMENT
POWER MEASUREMENT
MOTOR SHAFT ROTATING SPEED

The rotational speed shows that the motor IS NOT rotating at the specified rotational speed of 1200 R.P.M.
- Induction motor slip can account for a 2% to 3% reduction in rotation speed.
- The motor shaft rotational speed measurements show the shaft rotates at around 900 R.P.M. when the elevator is going up.
- The motor shaft rotational speed measurements show the shaft rotating in the range of 620-800 R.P.M. when the elevator is going down. The point that the rotational speed reaches 620 R.P.M. is the point at which the motor struggles the most. It sounds like the motor is about to stall. The only reason it doesn't (probably) is because of the increased run capacitance.

Highlights on the outstanding issue:
- The motor was rebuilt. The electric motor shop that rebuilt the motor indicated that they replicated the original number of turns and physical separation of the stator windings.
- The motor stator was rebuilt with 6 poles. The rotation speed of a 6 pole motor should be 1200 R.P.M.; however, the measured rotating speed is lower than the theoretical rotating speed.
- The motor has a harder time when the elevator is going down (counterweights going up). It is expected that the power is higher when the counterweights go up.
- With 90 uF run capacitance the motor stalls on the way down.
- With 120 uF run capacitance the motor draws 18-21 A rms, which is way more than the specified current of 7 Arms.
- With 120 uF the auxiliary winding voltage is 320 V rms and the auxiliary winding current is 19-21 Arms.

Notes on manual operation:
- With the motor brake disengaged is fairly easy, albeit tedious, to move the elevator up and down manually by rotating the motor shaft.
- The up/down force difference required to move the elevator manually is noticeable. It is harder to bring the elevator down (counterweights up), as expected.
- The one thing to note of manual operation is that the motor shaft is nowhere near rotating at 1200 R.P.M.

Questions on the outstanding issue:
Q3) Rather than asking a specific question, I'll take any advice or comment that could help better understand what's causing the motor to struggle so much.


Thank YOU so much for taking the time to read through all this!

Have you verified that the run windings and start windings are not reversed? Under load (empty car down) motor will struggle if windings are reversed. Car will run either way, it just won't be efficient. Also, it may affect synchronous speed. The limit switch that you are not using on the car functions as a Door Zone limit. When the car gets within 3" of the floor. a stationary cam pushes the lever on the L switch and unlocks the door so that you can get out. There are two contacts in that doorlock. One is called a closed door contact and one is called a door locked contact. On residential elevators of this vintage, you were allowed to jump out the locked contacts 3" above or below the floor or else you could never leave the floor. The door zone switch is in series with the closed contacts (33 to 41). The locked contacts are from 32 to 33. Whichever floor you are at has the locked contact open because the door is unlocked. When you set a call, the car takes off because the door zone and closed contacts allow current to flow. After 3", if the door did not lock, the car stops. If the door locked, then it continues on. Someone has removed some parts and/or jumped some circuits out. If you are not an elevator mechanic, I would highly suggest that you hire a reputable firm with and older mechanic .
Good Luck
Johnny

Most of these had emergency opener chains put through the wall to allow the doors to be opened when the car was away from the floor. If the chain is too tight, it won''t let the lock properly engage. You did not mention how much wipe or contact area you had on the copper and carbon contacts, or the condition of the shunts, or the auxiliary contacts. The H relay should be a long core timer or a pneumatic type timer. Does the stator grid have continuity?? Inquiring minds want to know.
Johnny

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.

Item 2 More details on the motor. You have a great deal of expertise on motors. I am just an average mechanic. If I were there, I would take the motor back to the shop that wound it and say, "put this on your bench, figure out how the wires should be hooked up to connect like this diagram says and make it draw the correct current and run the correct speed. If they have to rewind it again, so be it. They could also figure out the correct capacitance to connect with each winding." Get it right on the bench before playing in the field. There is a company in Chicago that specializes in old Otis equipment. If you had to start with a different stator and rotor, that might not be the worst thing. You are spending a lot of time and resources and don't seem to be gaining ground.

Item 3. 3.1 Good job. How much experience does this full Service Company have if they can't fix this simple problem??? 3.2 See 3.1, Did you notice the SOS switch. Did you incorporate that switch in that grouping??? 3.3 You need both sets of contacts to be used on this elevator. If not, either you won't have ANY doorlocks or after the first trip into the floor and unlocking the doors, you won't be able to leave the floor. 3.4 see 3.3.
3.5 CLOSED and LOCKED are two different things. Opening the door may stop the elevator, but it does not insure that the doors are locked.

Item 4. The OR circuit is only in effect for 3" above or below the floor. As soon as you run off the limit switch, one of the circuits are open and running depends on the other circuit. Any elevator parts house--Adams, SEES, Quality, etc. can provide a freight emergency keybox to allow the doors to be opened by a competent mechanic.

Item 5. The limit switches shown in your pictures are not of the vintage of this elevator. As long as the current rating is okay, they should be fine. The diagrams did not show the size of the control fuses, but I am fairly sure those contacts should do the job. The reason for a final limit switch at BOTH ends of the hoistway is so that the machine doesn't continue to run and either damage the cables or set fire to the building, or sever the cables if they run long enough. All of these things have happened.

Looking at your scope diagrams, it seems that your brake is not adjusted properly. Could be that there is still a problem with the motor (likely), but I see excessive current possibly brake not picking fast enough or stroke too long, oor cores too far apart. Regardless of motor, empty car up should not be a heavy draw. Have you balanced the car?? What percentage did you use?? 40 to 43 is standard for geared cars.

It looks like you are trying to do them a great job. Where is this project located???