New light fitting - Confused.

[kimbers]

I have just bought a new light fitting and have come to install and am slightly confused.

The existing ceiling rose is of the standard configuration.

3 live into the central terminal ( 2 supply, 1 switch )
3 earth into another terminal ( 2 supply, 1 switch )
2 neutral into a terminal ( 2 supply I think )
1 neutral into another terminal ( from switch I think )

With the 2 existing light fitting cables going to the 2 neutral terminals as you would expect.

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The new light fitting however has only 3 terminals, live, neutral and earth.

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The fitting comes with a spare single terminal block.

The existing ceiling rose needs to be removed, that's not problem. However I'm confused as to how to wire this up, mainly because the instructions have now caused me some confusion.

They state

"Where a ring/loop circuit exists, there may be a seperate set of wires which are not connected to the L,N or E of the fitting. They must be kept together in the vacant (loop) termial of the block supplied, or in a separate approved block (Not supplied ) and insulated from the rest of the fitting.

I not aware of any " extra set of wires".

Do I just take the L, N, and E of both existing supply cables and the existing switch cable, and connect respectively to the L, N and E of my new fitting?

This is probably obvious to most, maybe i'm thinking too hard about this, but the instrcutions make no mention of what I'm supposed to do with the existing switch wires.

It goes on to say

"Connect the supply wires to the terminal block of the fitting"

Again but makes no mention of the switch cables/wires?

Help!

 

[Chri5]

3 live into the central terminal ( 2 supply, 1 switch )
3 earth into another terminal ( 2 supply, 1 switch )
2 neutral into a terminal ( 2 supply I think )
1 neutral into another terminal ( from switch I think )

Wire as above to the terminals x3 + x1 that you have.

The fitting goes on the 2x neutrals terminal and then the switch live which is the one you think is a single neutral, that cable is the return switch live from the light switch, it should be marked with sleeve or tape in red (if neutrals are back) or brown, if the neutral is blue.

 

[Chri5]

3 live into the central terminal ( 2 supply, 1 switch )
3 earth into another terminal ( 2 supply, 1 switch )
2 neutral into a terminal ( 2 supply I think )
1 neutral into another terminal ( from switch I think )

Wire as above to the terminals x3 + x1 that you have.

The fitting goes on the 2x neutrals terminal and then the switch live which is the one you think is a single neutral, that cable is the return switch live from the light switch, it should be marked with sleeve or tape in red (if neutrals are back) or brown, if the neutral is blue.

 

[bhm1712]

one problem with the above - one of the 3 lives (reds) in the middle terminals cannot be the switched live...it is going to be a supply to the switch. There wont be a neutral going to the switch or coming back. This black cable on its own is likely to be the switched live coming back from the switch....without a bit of red sleeving to idenitify it correctly.

At its simplest there will be 1 live coming from the previous lamp fitting, 1 live going to the next fitting and 1 going to the switch.

There will be 1 neutral coming from the previous fitting, 1 going to the next.

There will be 1 earth coming from the previous fitting, 1 going to the switch and one going to the next fitting.

There will be one cable coming back from the switch - switched live.

The lamp bulb itself will have a live which goes to the same terminal as the single switched live, and one neutral connecting to the neutral terminal with the other 2

EDIT: Sorry Chri5 you beat me to it and i somehow managed to completely ignore your posts......Chri5 is correct

 

[kimbers]

Great, think I've got it then.

So

2 supply neutral to neutral on fitting.
1 switched live to live on fitting
3 x earth to earth on fitting.

3 x red live to separate terminal block on it's own?

 

[sparkybird]

yup

SB

 

[bhm1712]

i hate the way fitting manufacturers do not include the correct amount of terminals to accomodate domestic wiring!

The usual method is to terminal block the 2 neutrals together and on the other side of the connector run a wire to the lamp fitting neutral terminal, same with the earths. connect the lives in one connector as well - 2 in one end and one in the other. The the switched live can go straight to the lamp live terminal.

Its a ball ache and sometimes there isnt enough slack on the cable to do it neatly. Infact, its probably my biggest pet hate for domestic electrical.

EDIT:

if you can get the neutrals into the lamp terminal then great - its just soemtimes the new lamp terminals ( especially b&q ones) have tiny terminals or those push fit ones where only one wire can terminate. Then you need to terminal block the lot

 

[kimbers]

Thanks all. Got it sorted.

Unfortunately the B&Q instructions that came with this were not worth the paper they were written on. Totally misleading.

 

[bhm1712]

Yes they are poo, but once you have done one you know....most replacement lights are the same now. whenever i do one now, if try and mount terminals inside the new fitting to help - in the way the manufacturers should do (IMO) if its upstairs i fit a lighting junction box in the loft to terminate the cables rather than terminal block shoved into the void.