Relays in A lift’s control cabinet, 24 Sep 2011. I’m, not sure what the smaller relays on the left do but the larger relays (contactors) switch higher voltages and control things such as speeds and door safeties (top row), direction (U and D (up and down), UX and DX are an auxiliary for U and D). U and D have an interlocking system to prevent both being open or closed at the same time.
On the bottom row, C is for safeties, to prevent the lift from moving when the safeties (such as doors being open, or obstructed etc) are not in place, H controls the brakes and K runs the motor-generator set.