Wiring Nest Protect to lighting circuit

[Soong]

I quite like the idea of a wired Nest Protect mainly because I'm a geek but also the nightlight feature will come in handy. For that reason I think I would rather wired than battery.

Am I right in thinking what I need to do is run a 3-core (or 2?) wire from that junction box on the left to the Nest Protect? That junction box runs to two ceiling lights and it's between that where I would like the Nest Protect so it seems the most obvious point.

 

[flameport]

If that junction box contains permanent L, then a 3 core cable L,N,E from that to the device.
If it only has switched L inside, then of no use.

The junction box also needs to be securely fixed to something such as that wooden beam to the right of it, and the cables secured where they enter, rather than being left loose as it is now.

As it already has 5 cables connected, adding a 6th may not be easy or possible, replacing it with a larger box may be necessary.

 

[Soong]

Cheers! Got any recommendations for a new box that will easily fit 6 cables?

Definitely need to tidy everything up up there.

 

[flameport]

https://www.tlc-direct.co.uk/Products/WAGOBOXXL.html

 

[Soong]

Have only found 2 core stranded 0.75mm elec cable. Will that do? Will have to wait bloody ages for delivery otherwise.

 

[Soong]

Ignore my last post as I have now gotten some T&E.

Here's what's inside that junction box. The two with the blue tape feed the two upstairs lights. I assume my notes are correct and I can safetly connect the smoke alarm to L and N? Will get a new junction box as well.

 

[muffking]

The labelling is spot on. Wire up to your L, N & E.
You can do a Screwfix click & collect for what you need. Make sure you get enough Wagos for the box and with the right number of ways. Get yourself a pack of 1.5mm cable clips too they're not expensive.

 

[Soong]

Cheers!

 

[AndyPRK]

or use the existing junction box, which is easier

 

[Soong]

or use the existing junction box, which is easier

Yeah I think I will do that just so I can get it done today but when I can get to Screwfix I could definitely do with getting something a bit bigger and sorting out all the cabling so it's neat.

Feeling quite pleased with myself so far. I've changed face plates, I've added a wired smoke alarm, I've replaced ceiling roses.

I currently have a Honeywell Lyric T6 that I'd like to replace with a Nest Thermostat. Is that on the same kind of level as the above or should I get someone in?

 

[flameport]

I currently have a Honeywell Lyric T6 that I'd like to replace with a Nest Thermostat. Is that on the same kind of level as the above

Those and most other thermostats are an L&N for power and two wires as a switch.
If it's a proper heating system (i.e. not a combination boiler), there may be more switch wires but the principle is the same.