New light fitting - Live and Neutral wire question

[kieran5405]

Hi,

I have moved into a new house and want to change the current light to a new light. The current one is just your standard cord and bulb.

I have two pictures at the following link with shows the current light and the new light fitting

unscrewed the light part that is closest to the ceiling (as seen in current light picture) and as you can see there are about three brown and three blue wires. For my new light there is only one slot for Live and only one slot for Neutral. Am I supposed to join all the blue wires together and put them into their repective slot i.e. Neutral. And then do the same for the brown wires. As there is only one slot on the new light fitting for Neutral and on slot for Live.

Thanks.

[Bob Mannix]

No, because if you do and the light switch is OFF, the light will be on. If you then turn the light switch ON, there will be a bit of a bang, the breaker will trip and the switch contacts may be fused together.

You can see on your photo where the light L & N connect to, which is where your new light must connect to. I presume there is no room under this new light for the ceiling rose, in which case you have a problem. The correct solution in this circumstance is to take up the floor above (assuming there is one), fit the ceiling rose in the void and run the two core flex through to the light.

[manatbandq]

the wires in the lighting ring, the switch and the light fitting.

NO! The blue wires are not all joined together, they are joined in two banks.

Your lights are wired in a ring with the supply going from one fitting to the next with wires from each rose to it's respective lightswitch.

In your picture you have three blue neutral wires for the light fitting, the wire from the previous light fitting in the ring and the wire to the next fitting in the ring. In the middle are three live wires from the previous fitting, to the next fitting and to the switch. Then there are two wires, one from the switch and the brown one to the fitting. The three wires in the middle are NOT connected to the other two wires.

Your fitting must connect in the same place as the old one. Don't forget the earth wires, so you would need four "slots". Your fitting only has three.

You need a proper junction box (or re-use the existing rose) in the void above the ceiling.

MBQ

[Richard A Downing FBCS CITP]

There is no such thing as a 'lighting ring', it's a terminological inexactitude. What you have a light circuit wired on the loop-in principle. The advice on wiring is correct though.

See

need to convert from loop-in (ceiling rose) to junction-box wiring as shown clearly in the article.

R.

[John Rumm]

or simply add a one more of those terminal strip blocks to the new fitting to give you the extra.

[FaultyFiesta]

That's what I did a few days ago - the new light had only 3 terminals, so I added a single terminal block from a strip. Since then I've been wondering whether this is maybe bad practice or against regulations. Seems OK though.

[Dave Stanton]

Or even more correctly use a 4 terminal junction box instaed of the rose.

Dave

[John Rumm]

It is pretty standard practice, and also ok with the regs so long as you use an insulated terminal and it is fully enclosed in the box of the light fitting (i.e. not hanging out somewhere where it could be touched). If a chockie block terminal does not fit then a crimp usually will.

[kieran5405]

Hi all,

Thanks for all the input. I am now starting to see clearer what i should be doing.

Thank god i posted this topic cos i was just going to go ahead and do it but then started to think - there has to be a reason for so many wires!

To make things clearer for me. There is a void in the ceiling - so if i could put the ceiling rose (block that has the wires together) up into that and then use the existing single Live and existing single Neutral wires that currently go down to the existing bulb for the new light fitting. In that I put these two wires into the Live and Neutral slot of the new light. Then would i take the yellow and green striped wire as seen in current picture (which i presume is the earth wire) and put this in the middle slot of the new light (the earth slot). Will this work for me or should i do it another way.

One thing that concerns me about putting something into the void is with the wires heating and possibly starting a fire. If i put that block into the void - does the block get hot etc.. when the light is on. My concern would be if it was touching against something etc.

Thanks again for all help.

[Bob Mannix]

If it gets hot then there's something seriously wrong! (ie no it won't get hot). Yes, if an earth is provided for it should be used.

[kieran5405]

Cheers for that.

I am going to try and put the Block in the void and get the new light up.

One other question about the earth wire - I just want to go over this to be sure.

On -

the first photo the earth wire is the green and yellow striped wire. In the third photo (new photo i added), that striped wire from the first photo goes into the middle slot between the L and N - the slot maked with a circular smbol (which i presume means earth). Isn't that right.

Thanks.

[David Hansen]

On 31 Mar 2006 06:12:53 -0800 someone who may be [e-mail] wrote this:-

Then it must be inside a suitable enclosure.

[kieran5405]

Hi David,

When you say a 'suitable enclosure' - what do mean exactly and what would be suitable in this case.

Thanks.

[John]

Judging by your questions an electrician, or a 'friend' who knows about electrics!

Cheers

John

[kieran5405]

Thanks John.

But I'll never learn if I keep getting an electrician in. We all have to start somewhere....

Now does anyone know of an example of a 'suitable enclosure' so i can take a shot at this.

Thanks.

[Richard Conway]

Do you have access from above (i.e. under floorboards or in loft?)

[kieran5405]

unfort there is no way access can be gained from above.

[Owain]

If you've got a plasterboard ceiling one of these will probably do:

[David Hansen]

On 31 Mar 2006 06:28:09 -0800 someone who may be [e-mail] wrote this:-

A suitable enclosure is a term that exactly specifies what is necessary. I have not seen your ceiling and so cannot tell what would be suitable in your case. There is also the question of what precisely you mean by a block. It appears from other messages that you may be talking about a ceiling rose, which is in fact a suitable enclosure within which there are several terminal blocks.

What I might do in this sort of case is as follows:

1) Unscrew the ceiling rose fixing screws and see how much slack cable there is. 2) Probe to see if it is fitted to a joist slightly to the side of the centre. Assuming suitability from these two points go on to: 3) Replace the existing flex with three core flex. 4) Enlarge the holes the wires come through into one of hand size. 5) Fix the rose to the joist. Short screws and a short screwdriver are useful here. 6) Patch up the hole.

7) Fix the luminaire to the ceiling, covering up the patched hole.

This avoids dismantling the ceiling rose and labelling the cables to get them back the right way.

A major factor is the temperature the luminaire will reach. This affects the type of cable to use for the drop.

[kieran5405]

Cheers for all your help.

I kept the ceiling rose and used the void which worked well for the light fixture.

I wired it up and all is working fine.

Thanks again!!!