Greetings guys on the forum,
Congratulations for the excellent site.

This is my first post.

I am a maintenance technician with little experience
I'm trying to restore an 5 floor relays old elevator.
I was able to repair most of steps,
Someone pulled the relays and wire the steps of:
Up and down; speed change from fast to slow; open and close door.

I need to know if anyone of you can explain me, How this circuits work?
If anyone can help with this, I will be very grateful

Thanks in advance,
Oswaldo