I've got a single switch that I need to replace, in a room with no other switches and it is the only one that controls the light. I'd expect that the switch should be a 2 wire or similar, but on the back there are two input wires labelled live and neutral, and two output wires labelled live and neutral. I can't find a new switch unit to match this - is there some way that I can use a one or 2 way regular switch here? I'm at a loss as to what is so special about this switch, as all the other ones I've checked so far are the normal one and 2 way switching...
 
Thoughts?
 
diagram of the switch:
 

O         O

L OUT N
-----------
L   IN   N
O         O

 

Where the Os are the holes for the wires.

Your drawing looks like a double pole single throw switch, but I'd only ever expect to see one of those as the isolator on something like a shower (when isolator switch is in a "dry room") or possibly an immersion heater.

 

Of course, if I had one and needed a new light switch I might just use it anyway.

If you are saying all 4 terminals have wires connected you need one of these, but why it's wired that way beats me.

http://www.screwfix.com/p/crabtree-20a-dp-switch/85073

Could it not be that somebody has decided to connect the neutrals in this way, and therefore switched them, when really they just need to be connected together in a terminal block and the two live wires switched with a normal light switch.

I've just had a word with an electrician mate, and he was suggesting you might use a DPST with multi-LED luminaires, to make sure you kill all current in line and return.

Couple of years ago I wanted to fit a dimmer switch in lieu of the existing 4 wire switch, supply to 1 light bulb.

 

I asked a retired electrician in my local :beer: :cocktail:  he suggested to join the 2 neutral wires in a section of terminal strip and wire the dimmer L1 and L2 and it all worked.

 

He could not explain the reason for the 4 wire switch but mentioned it could be what was available in back of sparks van at the time and words including blinking bodgers and diy people.

OK, took the advise above and wired the two neutral together and used a standard switch, all good now. Still no idea why they decided to do it though. Only thing that might explain it is that this room may once have been a utility room, and they might have changed from an isolator, who knows...

 

Thanks anyway all.

Edited 4 September, 201510 yr by wiredsoftware

Becoming more common to wire lights this way, due to killing the live and neutral, incase of wrong polarity being a danger when relamping and the outer part of the lampholder being live

The previous owner might have been an industrial sparky and had these switches lying around; they do get used in places with no effective neutral - where 240v is taken off of a 3 phase supply and they need to isolate both sides.

 

I have come across such a 3 phase set-up where an idiot used single pole switches and the next person to touch it got fried - electrically and thermally!!

 

(From then on the guys nickname was "Scorch").