External Light Sensor Wiring Advice

karlitob

Hi all

Grateful for some advice if you could.

Under this radiator, there is an external light fitting. The front door is recessed under the bedroom.

This is the light fitting. I’m right under the radiator now.

The switch on the left controls the light.

The wire that connects the switch to the light is under the floor boards in front of the radiator circled in red.

I would like to connect into that wire and run it to the left of the radiator underneath which is press. I plan to bring the wire down there and drill out into the exterior wall where I’ll put an external sensor so that the light can come on/off dusk or people coming to the door.

I’ll connect using wagos and a wago box.

I have three questions (some might be a bit simple).

• What’s the name of that type of wire so I can purchase it at an electrical supply shop.

• You’ll see a screw coming through a yellow rawl plug. My handiwork. Any suggestions on what to stick on top of it so that it doesn’t catch anything.

• Finally - any comments welcome. Perhaps on the brand / quality of the sensor. I’d like something discreet and not overt at all.

Thank you.

10-10-20

Hi!

1. The cable used to be called Twin & Earth (T&E) but is now called CPC (Circuit Protective Conductor) by some.
2. A bottle cork.

10-10-20

As the new sensor will have both L and switched-L, you may wish to run a separate double-insulated single core cable with it. Example:

https://www.eurosales.ie/products/double-insulated-single-core-6181b-lszh-dca-spvcpvccbldca.html?filter_set[]=4776,4777,4778,4800

GreeBo

Regarding the rawl plug/screw. You have a perfectly good joist 1 inch away, remove the rawl plug and screw into the joist for a much better job.

10-10-20

https://www.boards.ie/discussion/comment/121767315#Comment_121767315

Better than a cork anyway. I sometimes put a lat up into the ceiling and then screw into that.

karlitob

https://www.boards.ie/discussion/comment/121767315#Comment_121767315

Good suggestion but the rose of the fitting underneath is centred. To move it to the joist would affect below.

A cork isn’t a bad suggestion.

Drilling into these spaces is nerve racking and a lottery. I really dislike doing it.

karlitob

https://www.boards.ie/discussion/comment/121767291#Comment_121767291

Thanks for that.

This is where the stupid questions come in. I knew it was a twin and earth but the flat grey wire is more robust than normal white wire. I know there’s differences in conductor size.

I presuming here that once I connect the new wire into the wago connection that there’ll be a free end (for a while at least until I buy the sensor) and I can simply terminate that in another wago and box.

Could I ask you to explain - as though you would to an idiot - what you mean by ‘run a separate double insulate single core with that’.

meercat

You’ll require a 4 core 1.5 nymj cable to run from this light to your new sensor position (live,neutral,earth and switched live)

you’ll need to leave the light switched on permanently

karlitob

https://www.boards.ie/discussion/comment/121768735#Comment_121768735

Thank you for this. Much obliged.

Can I ask two more questions.

• I presumed I would cut into the current wire and connect a wire in there. But I think what you’re saying is run the 4 core from the fitting rose itself to wherever I’m bring the wire. Is that correct?

• any recommendations of small discrete sensor?

many thanks

mickdw

I guess you could just replace the light with a light with integrated sensor and save yourself a lot of messing.

meercat

Mickdw above probably has the best suggestion

if you put the motion detector on the front then the light probably won’t activate if someone comes out of the house (until they get in range of the sensor). It will activate if they come in driveway though.

it’s also pointless having a dusk/dawn and motion sensor

karlitob

https://www.boards.ie/discussion/comment/121769109#Comment_121769109

I hear you.

I pedantic and took me ages to find the light fixture that I like. But you’re probably right.

karlitob

https://www.boards.ie/discussion/comment/121769506#Comment_121769506

Point well made. Not too worried about the egress more the ingress.

can I ask why Dawn/dusk is pointless.

tomhammer..

https://www.boards.ie/discussion/comment/121769997#Comment_121769997

A motion sensor has the dusk/dawn built-in

karlitob

https://www.boards.ie/discussion/comment/121770158#Comment_121770158

Apologies I must’ve typed it in wrong or inaccurately above. As I understood it The PIR has a motion sensor and a dawn dusk together. But calling it a motions was inaccurate on my part. Thanks for the post.

karlitob

https://www.boards.ie/discussion/comment/121770158#Comment_121770158

Apologies I must’ve typed it in wrong or inaccurately above. As I understood it The PIR has a motion sensor and a dawn dusk together. But calling it a motions was inaccurate on my part. Thanks for the post.

karlitob

Hi

Is this cable ok to use?

https://www.screwfix.ie/p/time-3184y-white-4-core-1mm-flexible-cable-5m-coil/74464#product_additional_details_container

Thanks