by ericmark »
Wed May 25, 2016 11:31 am
It is rare, but not unknown for light switches to have a neutral connection, often the black/blue wire is used for line it should have a sleeve on it to show it is line either red or brown but often these sleeves are missing.
The standard light switch will normally have Com, L1, and L2 some replace the Com with L1 so have L1, L2, and L3. Simple on/off switches only have two terminals but often the casing still has same numbers just nothing in the hole for the L2 or L3 terminal. This is true for on/off and two way switches.
There is also a switch called an intermediate, which is used where you want 3 or more switches to work the same lamp. In this case the switch has 4 terminals, there is also a double pole switch which again has 4 terminals, They look the same and really only way to work out which you have is to use a multi-meter.
The intermediate switch can be used for two way and on/off so a plate with two intermediate switches can have one used as two way and one used as intermediate. For on/off normally it is one terminal either end of the switch. What the switch does is swap the two wires around like a reversing switch.
