Connecting spotlights and new switch in a new room

Calliman12 · Jun 26, 2022

Hi all new here and hoping for some advice.
I had added a new room to my house and want to add new spotlights and a new switch to the lighting circuit. My house is 1990's built in England UK, and looped in at the ceiling rose so the bedroom next door has 3 cables going to it. I would like to use this to power the spotlights in the new room controlled with the new switch.

I think i need to splice into one of the wires (not the switch wire) from the room next door with a junction box. I'm struggling to connect up the new switch cable and power up the new lights. Could someone please shed some light on which cables to splice into and how to hook up the new spot lights (ones i have can be daisy chained)? I have all the cables in place and a bunch of Wago junction boxes and connectors just need advice on the connections.

Many thanks in advance,

K.C

Dartlec · Jun 27, 2022

A picture may help, but it's likely that the ceiling rose with 3 cables in has the following:

1 cable in from consumer unit (via other fittings)
1 cable to the switch - this should have the black (or possibly blue if newer) core into the switched live part of the ceiling rose, and hopefully some red or brown tape or sleeving on it.
1 cable out to the next fitting in the loop

The feed to the new room could be taken from either of the non switch cables, by joining above the ceiling with wago connectors and a wago box. This is obviously easier if it's an upstairs room so you can access from the loft.

The simplest method and one most often used now is to take the new cable to the location of the new switch. Then take a cable from it to your new lights, daisy chaining as appropriate.

The important thing to note is that only the live cores are connected to the switch - the neutrals are joined in a wago connector behind the switch.

The advantage of this system is that a smart switch can be easy installed at a later date.

There are a couple of important things to note though.

If you are adding a new lighting point, it must be RCD protected. If your house is 90s built, the lighting circuit may not have an RCD on it. It can often be upgraded without significant cost, but that is a job for an electrician.

It's also important, especially when daisy chaining lights, to ensure that the "earth" (cpc) cable is continuous through the install. This is easily missed and everything will work correctly without it, but it is an essential part of the safety of the install in the event of a fault, especially if you have metal light fittings or switches, so it really needs testing before the installation is put into service.

If you're not sure how to do that, it may be best to employ an electrician for an hour, even if you install the wires and get them to test it.

I'm assuming that the new light isn't in a bathroom, because if it is, then it is notifiable under Part P of the building regulations which would need an electrician in any case.

Calliman12 · Jun 30, 2022

Dartlec said:
A picture may help, but it's likely that the ceiling rose with 3 cables in has the following:

1 cable in from consumer unit (via other fittings)
1 cable to the switch - this should have the black (or possibly blue if newer) core into the switched live part of the ceiling rose, and hopefully some red or brown tape or sleeving on it.
1 cable out to the next fitting in the loop

The feed to the new room could be taken from either of the non switch cables, by joining above the ceiling with wago connectors and a wago box. This is obviously easier if it's an upstairs room so you can access from the loft.

The simplest method and one most often used now is to take the new cable to the location of the new switch. Then take a cable from it to your new lights, daisy chaining as appropriate.

The important thing to note is that only the live cores are connected to the switch - the neutrals are joined in a wago connector behind the switch.

The advantage of this system is that a smart switch can be easy installed at a later date.

There are a couple of important things to note though.

If you are adding a new lighting point, it must be RCD protected. If your house is 90s built, the lighting circuit may not have an RCD on it. It can often be upgraded without significant cost, but that is a job for an electrician.

It's also important, especially when daisy chaining lights, to ensure that the "earth" (cpc) cable is continuous through the install. This is easily missed and everything will work correctly without it, but it is an essential part of the safety of the install in the event of a fault, especially if you have metal light fittings or switches, so it really needs testing before the installation is put into service.

If you're not sure how to do that, it may be best to employ an electrician for an hour, even if you install the wires and get them to test it.

I'm assuming that the new light isn't in a bathroom, because if it is, then it is notifiable under Part P of the building regulations which would need an electrician in any case.