Schaefer
Schaefer is a company that produces elevator products such as displays and buttons. I have worked on a few elevator parts with Schaefer buttons.
Style 28 Buttons
Thyssen Call Button
For this project, I clean up and wire this Thyssen elevator button. It has Schaefer KT28 buttons.
Style 28 Wiring
Below are a few diagrams which show how to wire up these buttons and what each pin stands for (this information is also available on the side of the button itself). The wiring diagram shows how to connect the buttons with LEDs together. A single button is wired in the same way (without the other button, obviously).
Style 28 base layout
Pin Functions
11 (21) - Switch NC13 (23) - Switch NO12 (22) - Switch CommonL1 - LampL2 - Lamp14 - LED +24 - LED -
LED Button Intermediate wiring diagram
(This is what was used in the Thyssen call button video)