Outside light to 2 gang

[Lostmejunk]

Hi, excuse the ignorance here but I am currently replacing an existing switch with a 2 gang to wire up a new outside light. The current switch has a live, neutral and earth feed (which appears to be only from the ceiling rose). The new outside light has the same. How/can I wire this correctly? I presume I should bridge between the COM port but how do I wire the new light to work correctly? Standard gang with com, L1 and L2 for each switch. Old switch works fine as you would expect an I missing an additional feed?
Source URL: https://www.electriciansforums.net/threads/outside-light-wiring.181934/#post-1598202

 

[ProDave]

I am not convinced you have understood what you have at your light switch.

Forget naming the conductors for a moment,  Are you saying you presently have a single gang light switch,  and connected to that switch is ONE cable that has a red and a black core, and it's earth core? and the red and black connect to the switch COM and L1?

Is that all you have at the moment?

 

[Murdoch]

I am not convinced you have understood what you have at your light switch.

Forget naming the conductors for a moment,  Are you saying you presently have a single gang light switch,  and connected to that switch is ONE cable that has a red and a black core, and it's earth core? and the red and black connect to the switch COM and L1?

Is that all you have at the moment?

or do you have 1 brown core, 1 blue core and 1 sleeved green and yellow

If this is the case you don't have a neutral and your new light won't work .......

 

[Lostmejunk]

Yes Murdoch that’s absolutely correct 

 

[Murdoch]

Yes Murdoch that’s absolutely correct 

So without major surgery on your house, adding an outside light isn't really an option, unless its in a "sunny" position and you try a solar unit or a battery powered unit.

 

[Lostmejunk]

Where is the best place to take a neutral feed from?

 

[Murdoch]

Where is the best place to take a neutral feed from?

The cable your spark runs in for you.....................

And if you have a dual RCD fuseboard don't even consider running it from another circuit or you could well loose the whole house electrics

 

[Lostmejunk]

I may be dense but that’s even stretching it for me

 

[ProDave]

So at the moment you only have live, and switched live at the switch (and earth)

I would suggest the easiest way to rectify this, is replace the 2 core switch drop cable with a 3 core & earth cable and bring the neutral down from the ceiling rose with the third core.  That will guarantee it is the correct neutral.  Then you will be able to take a 2 core & earth out to the outside light with the additional switch,

 

[Lostmejunk]

Thanks ProDave, will get a sparky in to do it. Really appreciate the advice