Changing a single light switch to a twin switch

[Horatio]

I need to put an additional light on an outbuilding, the building already has a switchable internal light but I want to add a permanently on (dusk til dawn sensor) light to the exterior. I thought to use the same supply as the interior light but just add a twin switch so that the interior can be turned off but the supply to the exterior remains intact. The single switch is simple connections for load and supply designated with L,N and earth. However the twin switch I bought has the two switches designated each with Common and L1,L2. How do I connect this with the supply and the feed to the two light units?

Thanks

 

[Spark123]

Are you sure there is L&N in the switch? If so you can joint the neutrals together in a piece of chock block, red supply to C on one switch with a loop of wire connecting across to C on the other switch. Supply to the internal lamp from L1 on one switch and supply to outside light from L1 on the other switch. Join all the earths together in a chock block and loop out to the back box and switch if required. (What I am trying to say is don't rely on a crappy back box terminal for your earths).

 

[ban-all-sheds]

The single switch is simple connections for load and supply designated with L,N and earth.

It is just an ordinary switch is it, not a switched fused connection unit?

And are there two twin & earth cables going to it, or one?

 

[Steve]

ban, it could be a 20A switch.

 

[ban-all-sheds]

Indeed it could.

But as this is an outbuilding, it could be a switched FCU from the circuit supplying sockets in it. In which case replacing it with a 2G light switch might not be the cleverest of moves...

 

[Spark123]

Well spotted ban!! I must admit I was thinking 20A DP too.

 

[Steve]

must admit, i didnt read all of the post that mentioned where this switch was or what it was feeding!