Two external wall lights to internal switch.

[Kevin Hayden]

Hi,

I need to put up two external wall lights onto my kitchen extension. The builders electrician did part of the work last year, but as I did not have the lights he just fitted the wiring. I now need to wire up the two external lights either side of my door and then connect them to my internal light switch.

I have two twin and earth cables at the back of my internal light switch and then on the outside of my kitchen I have a single twin and earth cable coming out of the wall and then looping back into the same wall. Then on the other side of my door I have a single twin and earth coming out of the wall.

I’m guessing the lights will be fitted in series, so my thoughts are;

(1).Power off at my main electrical box.
(2).Then cut the twin and earth loop coming out of my external wall and connect to my first light.

Cutting the wire loop will give me, two lives (brown) going to my live connector on my light.
Two neutral (blue) going to my neutral connector on my light.
Two earth’s going to my earth connector on my light.

(3). Connect the second light to the single twin and earth coming out of my external wall on the other side of my door.

One live (brown) going to my live connector on my light.
One neutral (blue) going to my neutral connector on my light.
One earth’s going to my earth connector on my light.

(4). Connect the two twin and earth internal cables to my internal kitchen light switch.

This is were I’m unsure. If my lights are in series why do I have two internal twin and earth cables?

My light switch is 2 gang, with one side controlling my main kitchen lights. The other side of the switch is empty, but has the usual three connectors, a single L at the top and then a L1 and L2 at the bottom.

Would I connect the two live wires (brown) to L and the two neutral wires (blue) to L1?

I hope this makes sense, and any advise would be welcome. Thanks for your time.

 

[flameport]

If my lights are in series why do I have two internal twin and earth cables?

The problem here is that it's not known what the builder actually did with the cables. Guessing is a sure way to disaster.

Could the 'loop' outside actually be a single cable with the end just shoved into the wall / cemented over?

Are there any neutrals behind inside light switch?

Pictures of the cabling would be helpful.

Would I connect the two live wires (brown) to L and the two neutral wires (blue) to L1?

No.

 

[Kevin Hayden]

Hi Flameport,

Thanks for getting back to me, I have had another look at the looped cable and I'm 99% sure it is looped. I can't pull either side out of the wall and the hole is quite big, so no cement etc. to be seen. Is this unusual?

I have also attached 3 picks.

One of the internal light switch
One of the loop and one of the single twin and earth.

The loop is on the left hand side of the door on the same side as the internal switch and the single cable is on the right hand side of my door.

On the switch pic, you can see my main kitchen light wires (3 core and earth) on the left and then the two twin and earth on the right.

Hope

 

[rsgaz]

why do I have two internal twin and earth cables?

One should be the supply cable, the other is the outgoing (or 'load') cable.

 

[Kevin Hayden]

Hi Rsgaz,

Thanks, this makes sense. But how do I connect the switch? As flameport has said no to my suggestion of connecting the two live wires (brown) to L and the two neutral wires (blue) to L1?

 

[rsgaz]

The two blues need to be joined together in a terminal block...(i.e. just one 'segment' of these)

Then the two browns go to the switch. You must connect the earth wire of both cables, to what's already there in the back box, even if your new lights say they don't need an earth.

 

[Kevin Hayden]

Hi Rsgaz,

So, if I have understood you correctly I have attached a pic with how I have wired up my switch.

I have put the two live wires (brown) into L at the top of my switch. Put both neutrals (blue) into a terminal block and then put my two earths into the earth terminal of my swithch. The new wiring is on the right of the pic and the untouched original main light wiring is on the left.

Thanks for your help with this.

 

[rsgaz]

I have put the two live wires (brown) into L

‍

No, only put one brown into the 'common' that they are in now, and the other brown into L1 at the bottom. Doesn't matter which brown is which, it is the switch that joins them together when it is on.

 

[Kevin Hayden]

Hi Rsgaz,

Sorry, my bad.

I have now moved one of my brown wires into L1 (Pic attached). Still not working, and now I have put the power back I have lost my main kitchen light. This is the one on the left of the pic. Nothing tripped and all my fuses are fine, I have not touched this, so something strange is going on. I will replace the swictch tomorrow and post back.

Thanks for your help.

 

[rsgaz]

and now I have put the power back I have lost my main kitchen light.

That is odd.

Time to get out the multimeter and find out exactly what's going on with all your cables behind that switch. You need to find out where the 'supply T&E' is fed from. This could be a nearby ceiling rose, but then again, could be a hidden junction box somewhere above the ceiling, there are many possibilities. Even direct to the consumer unit is possible.

Or, get the electrician back and pay him to sort it for you.

 

[Kevin Hayden]

Hi Rsgaz,

I think you are right, time to get someone in who knows what they are doing as I'm clealy making things worse. Just frustrating as I thought that putting up two lights and conecting them would be a simple job.

Just for my education, if all my fuses are still Ok and my kitchen spots work fine what could I have possable done to the supply cable to affect a set of lights that to me, don't interact with each other?

Thanks.

 

[terryplumb]

Hello Kevin ,a few things... The two t/e cables that were behind the switch ,and before you made any connections , how where they terminated by the builder/ spark ? If your main kitchen light does not now work , check the original connections on the switch ,you may have loosened or broken one of the conductors. As mentioned earlier ,you are guessing what the cables / conductors are , which isnt wise . put things back to the way they were and call in a spark.

 

[flameport]

Still not working, and now I have put the power back I have lost my main kitchen light.

Were the two cables connected to anything else before you did anything? Such as connector(s) on the ends of them, or joined together in some way?
What have you done with the outside cables?

 

[333rocky333]

Its not possible to have 3 cable ends, or 5 now you have cut it, disconnect all relevant cables, if you have a multimeter, then check continuity from left outside end to right outside end, that will confirm your thoughts that the cable runs between each outside point.
Then with the remaining outside end, check continuity from there to the wires behind the switch and hopefully is one of them, as for the other wire behind the switch dont know.
Its possible that he planned to put the outside lights on a seperate circuit and not with the kitchen lights and the missing end is back at the fusebox

Also shouldn't the base plates be fitted so the fixing studs are horizontal so when you fix the light it is straight

 

[FrodoOne]

I’m guessing the lights will be fitted in series, so .............

To date, no one has as yet picked up on this:-
The two lights must be connected in parallel - BUT are "daisy-chained", with one T&E going from the switch to the first light, where the parallel connection is made to the T&E going to the second light.