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Other Do we have an Electrician in the house? Or someone that has more sense than me on electrical stuff?

Discussion in 'Hardware' started by nimbu, 2 Jan 2018.

  1. nimbu

    nimbu Well-Known Member

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    Is the neutral part of lighting circuits all the same?

    From my google fu, as I understand it they should be. Lighting main doesnt go back to the RCD and ceiling roses / junction boxes are used to "addon" rooms.

    I ask because in my Living / dining room I have 8 wall lights divided into 4 per room and each has its own switch. I wanted to do away and control it all from one switch. So basically can I take the common wire from one switch and add it to the other common and completely forget about the other live wire? (Would put a chopblock on it and then tape it up)

    The bad diagram below should explain what I am trying to do:

    https://drive.google.com/file/d/1H7S8pU7Zp0m0AcJa5uWMSXOcBPQg2_4p/view?usp=sharing
     
  2. Unicorn

    Unicorn Uniform November India

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    Lighting circuits in the UK are known as radial. They take live, neutral and earth to the first ceiling rose in the circuit from the fuse board, then the same on to the next rose, and the next and so on. There will be switch wires to the switch for each fitting or fittings from each rose. So yes, the neutral is common. If you opened up your consumer unit you'd see at least two neutral blocks - one would be for the lighting circuits in the house. Each lighting fuse unit's neutral would be connected to it.

    What you'll probably find behind 3 of each sets of 4 lights is a pair of lives, neutrals and earths. One is a feed and the other is a loop out to the next fitting in the circuit. Behind the other one (probably whichever is closest to the switch) you'll find the same with additional twin red and earth - those are the switch wires for that circuit. To combine the two circuits into one switch you don't need to do anything with lives or neutrals from the other circuit - they're already receiving live and neutral from that circuit. It's the switch wire(s) that need to be changed.

    This all assumes that the house is currently wired as standard and not with the older colour code of black neutrals and red lives; that change was made in the mid 2000s. This is not what I do for a living, but I've wired my own workshop and office, rewired my garage and have to install the occasional spur for computers, servers etc in offices. Always have a qualified electrician come to check and test any wiring you do yourself when you've finished and got it working. It's not as expensive as hiring them to do it themselves, but worthwhile since some property insurance (especially commercial) will ask to see an up to date EICR any time there is a claim for damage which could have been caused by an electrical fault.
     
  3. nimbu

    nimbu Well-Known Member

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    Cheers dude. Wiring is indeed radial, however you can see quite a mix of colours behind the sockets.

    So far I've seen grey, red, black, blue, brown, solid yellow and green and yellow.

    The lights in question run to 2 gang switch and appear to be individual runs. Ie live, switched live for each of the sets of lights.

    I actually plan to rewire at some point but first the kitchen needs doing, plan is to drop a new larger consumer unit, transfer the kitchen to that and then the rest of the house when I get that done.
     

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