Struggling to correctly wire a two gang rocker switch.

[ridgeback]

I've read through as many posts as possible and i am still at a loss. Any advice would be appreciate.

I previously had a porch light that was operated from a single gang rocker switch. Pretty straight forward. Red, Black and earth cables fitted into the relevant two connectors on the rear of the switch with the earth being attached directly to the socket casing.

I have now purchased a welcome light which has been mounted outside the front door. The cabling has been routed through the wall and directly down to the original porch light switch position. I have replaced the single rocker with a twin two gang rocker. This has three connectors per switch. Com, L1 and L2.

I have the two wires coming from the original light in the porch ceiling (Black and Red) and the same from the new light that has been fitted. plus earths from both.

I have spent 3 hours now, with no luck trying to get the porch light and exterior welcome light to operate from each switch on the 2 gang twin rocker and all i can manage is either 1 light operating.

What is the correct layout for the wiring please ????

 

[neds]

If you take a picture of the offending item, someone can tell you exactly which wire goes where.

 

[ridgeback]

Thanks. Will stick a photo on tomorrow. Oh....is it possible to just cut and paste a photo on, or do i need to do something else ?


Ridge.

 

[ridgeback]

Hehe...hope this works

Can't get a photo till the morning, but this may e of some assistance.

Wires on the right come from the original live porch light to the switch. Wires on the left come the new light source that is not live. Both earths are connected to the earth connector on the back box.

Please note that the two com connectors are actually in the middle of the L connectors and not as shown in the drawing


Ridge

 

[Steve]

OK, so you have an existing light, whose cable you believe comes directly to this switch. So where does the power come from if this were the case? That CANNOT work. There is a junction box somewhere. One thing is for sure, you do not have a neutral at that switch so cannot feed a new light off it. You must find that junction box, or some live feed from somewhere. Sorry.

 

[ridgeback]

OH Damn !!!

The original rocker switch was used to turn the power on/off to the indoor porch light. I assumed that i could run the power from that on to the new light. I assume from your comments that this is not possible.

 

[Adam_151]

No, its not, you don't have a neutral there, only a switch feed and a switch wire.

You need to get a neutral from somewhere on the same circuit... if the supply cables loop into the porch light, then another T+E from there down to the switch position would do the job

 

[Steve]

If only people understood the wonders of the basic lighting circuit . . . .

 

[ban-all-sheds]

Or even that lights etc need live and neutral to work....

 

[ridgeback]

If only people understood the wonders of the basic lighting circuit . . . .

I appreciate those that have offered advice. I must admit, my knowlege of lighting circuits is pretty much zero.

If i had understood the wonders of a basic lighting circuit, do you not think that i would not have posted in the first place

 

[Click-Sure]

Kind of strange that with the lighting circuit being the oldest (lighting was pretty much the only use of electricity when it first came out) kind of circuit that it should be one of the most complicated in the modern day.

Try a modified S Plan heating system, even that is beaten in complexity by some lighting circuits I have seen.

 

[ban-all-sheds]

If only people understood the wonders of the basic lighting circuit . . . .

I appreciate those that have offered advice. I must admit, my knowlege of lighting circuits is pretty much zero.

So why did you think you'd be able to add another light to the circuit without doing some learning first?

And do you really not know that electrical appliances need live and neutral connected to them?

I'm not having a go, just curious about what thought processes you went through...

 

[Steve]

Kind of strange that with the lighting circuit being the oldest (lighting was pretty much the only use of electricity when it first came out) kind of circuit that it should be one of the most complicated in the modern day.

Complicated, I think not. Sketch the most basic lamp, power source and switch. Join them with 3 wires. You have a lighting circuit. This is all there is to a basic modern household lighting circuit. Even with two 2-way switches, the sketched circuit is very simple and can easily be seen to work on paper.

What DIYers get confused with is those pesky black/blue wires at the switch! Which they assume to be neutral. They dont go into a thought process about how a switch would work with only one live and one neutral. Hurray for double red! Lets not go into those 3c+e cables here though eh.