Hello I have a pre made board which has a switch wired in a fashion I can’t work out.
The switch as far as I can tell is SPST however it has 3 terminals. 2 of these terminals when tested with a multimeter are connected when the switch is on and disconnected when the switch is off. The third terminal however seems to be never connected to either of the other two terminals regardless of the switch position.
Oddly the board has been wired so that the Live wire is connected to both the board and the mystery 3rd terminal. the Neutral wire goes via the two “working” terminals on the switch.
I have attached a sketch of the wiring as well as a picture of the switch.
Can anyone explain what this third terminal might be doing or why is is wired in an apparently pointless mannor?
Thanks in advance