Wiring for lights-Earthing required?

[Blair]

I am about to take possession of a new build flat and all the lights are the dangling wire type and I will be replacing them with light fittings of various sorts. Some are double insulated which don't require earthing but will I find that the sockets are wired with twin wires only and no earth? Most of the other fittings are provided with an earth point. Do I need to worry if there is no earth wire fitted? I would like to know before I tackle the job. Blair

[Dave Plowman (News)]

New installation lighting circuits have been required to provide an earth for many years.

[Tim Mitchell]

In article , Blair writes

If new build, you should find that the ceiling roses all have an earth wire.

You do need to worry if there is no earth wire, and your light fitting is not double insulated. They do have to be earthed.

[Blair]

Thanks for you help. I have 6 light fittings to fit but one definitely states that it is double insulated and on no account must an earth connection be made. It's made of all plastic. Blair

[Owain]

The lighting fitting may be made of plastic and double insulated but the earths in the cable must be properly terminated. If there isn't a spare terminal on the fitting, use a single piece of insulated 'chocolate block' to connect all the earths together and make sure all the bare earth wires have green&yellow sleeving.

Even though this fitting may not require an earth, you must connect the earths together so the earth is continued down the cable to the next and subsequent fittings.

Owain

[Dave Plowman (News)]

However, the ECC should still go on to the next outlet regardless of whether it's needed at this particular one.

[Blair]

Thanks for your warning. But I am still not sure about it. For instance I assume the cable coming to the light fitting will have one earth lead. If there is no earth terminal on the new fitting I can fit a choc block to its end but where is the other earth wire to make the earth continue to the next fitting? Sorry to be so dim Blair

[Tim Mitchell]

In article , Blair writes

The lighting power is normally wired in a "daisy chain" around all the light fittings, so most ceiling roses will have an incoming and outgoing cable (plus a third cable to the light switch, usually)

Owain was saying that the earths in the incoming, outgoing and light switch cables must all be connected together.

[Dave Plowman (News)]

On most ceiling roses there will be three TW&E cables - the feed, switch drop and loop on to the next rose. So there could be be three earths. And it's important to make sure the one to the switch is present and correct - as some metal plate switches and dimmers *must* be earthed.

[Blair]

Thanks to all for your help I now understand and will be ready when I get the key to the house Thanks Blair

[Blair]

I have now obtained access to my flat and the first fitting has only one cable with earth, live and neutral so there is no problem wiring the fitting which has an earth terminal. But in the case of one of my fittings which is all plastic and has no earth terminal, what do I do with the earth wire? How does it go on to the next outlet? Blair

[Tim Mitchell]

In article , Blair writes

If there is only one cable, there must be a junction box elsewhere to feed other lights. For a double insulated fitting you should terminate the earth in a single piece of choc block if there is no earth terminal in the fitting.

[Dave Plowman (News)]

Is this the cable in the ceiling? If so there must be a junction box elsewhere - or the feed goes via the light switch.

The most common wiring method is a ceiling rose with all the connections within it. It will be obvious if you have this method when you remove the cover. However, if the new property was designed to allow your choice of fittings everywhere rather than simple pendant fittings, it would make sense to use junction boxes with just one TW&E to each outlet. In which case you don't have to worry about earth continuity for the circuit.

[buffdad1]

call an electrician

[Blair]

Yes it is a simple ceiling pendant with all the connections within it. I have removed the ceiling rose and connecting block so am left with only 3 wires Live, Neutral and earth. Tim suggested ending the earth terminal with a choc block. What would that do? Blair

[Blair]

There e is no earth terminal in the fitting. The sheet issued with it stressed that an earth must not be fitted What does ending the earth in a choc block achieves? Can I not just cut off the earth wire? Blair

[Dave Plowman (News)]

Yup. It's simply to keep it safe from shorting on something. It should be sleeved too.

[Dave Plowman (News)]

What happens when the fitting is changed for one that *does* need an earth?