"I can't even work out how the builder(s) managed that"

You have a master switch which is a simple on/off switch - when it's off the circuit is broken at that point, and when it's on it is connected.


The other two have a pair of wires between them, A and B, and when both switches are "on" they are both connected to A so the circuit is complete across that point, and likewise when they're both "off". When they're not pointing the same way there's no circuit.
This is useful because (assuming the master switch is on in your situation) you can control whether the lights are on or off from either switch - so you can have a switch at the top and bottom of a set of stairs for example.


I can see why it'd make sense depending on the location of the switches, but it is a little odd.
(phyphor, Sat 12 Mar 2011, 23:34, 1 reply)

The "master" one is on the landing, the other two are at the top and bottom of the stairs.
Also, to forestall your next question, I don't know why there are two switches upstairs. Especially as they're less than five feet apart.
( The Mock TurtIe ™ --- Thinks you are a cunt, on, Sat 12 Mar 2011, 23:42, closed)

The landing switch ..
.... looks like it's there to stop the light being turned on from the bottom. Is the bottom of the stairs in a public area or somewhere that might result in the light being turned on by mistake? Maybe someone upstairs used to find the light disturbing and wanted to be able to over-ride it. Humm...
( Ugi , it's a game of give and cake, Mon 14 Mar 2011, 11:30, closed)

Nope.
The entire circuit is contained within my flat, and can't be accessed from the outside.
( The Mock TurtIe ™ --- Thinks you are a cunt, on, Wed 16 Mar 2011, 1:33, closed)