Replacing a ceiling rose with a new light fixture

[alex381]

Hi,

I've bought a new light fitting, but am struggling to understand how to wire it correctly. The image in the following link matches what I am trying to do, but the wiring seems to be different to what I currently have:

http://imageshack.us/photo/my-images/528/chockblock3nk.gif/

As per the diagram, in the light switch, I have a red wire attached to "COM" and a black wire with red sleeve attached to "L1".

However when it comes to the ceiling rose, this seems to be different. See the image below:



The wiring clearly shows that the black wire with red sleeve (from the ceiling) is connected to the blue wire of the light. It also shows that the black wire (from the ceiling) is connected to the brown wire of the light. which is backwards!

However, the light switch is not upside and if ,when I put the new light fitting in, I follow the wiring from the diagram in the above link, the light switch will then be upside down (i.e. light will be on when in the switch is set to off).

The only thing I can assume is that the red sleeve is on the wrong black cable ... does anyone agree with this? If I wire up the new light to match how it is currently wired will this cause any problems?

Also, the 2 red wires, can these be simply twisted together and placed in the same side of the terminal, or should I have one in one side and the other in the otherside ... and does it make any difference?!

I've purposely not mentioned the earth's for simplicity, as I know I need to connect these up, and they are easy to do!

Sorry for all the questions in my first post, but I will be very grateful for any advice.

Thanking you in advance,

Alex

 

[PrenticeBoyofDerry]

The way the fitting in the image on your post is terminated will operate the light.
Ideally the sleeved black(live) and un-sleeved black(neutral) should be swapped as the switch live sleeved black should be connected at the brown flex terminal, in some light fitting this is important due to safety against electrical shock.
The red cables are your looped live, should not be twisted together and be terminated together but not with any other conductors..
What's the white stuff on blue and brown flex of light?

 

[Chri5]

The numpty that wired the light fitting did it back to front, not a big issue but it is wrong.

The switched live with the red collar goes to the brown and the blue goes to the neutrals (black in the old colour system).

Just make sure you mimic the same as the rose is doing and all will be good.

To prevent any doubt, if you look at the rose lhs the bank of terminals under the clear plastic are no all individual, they are 3 groups. So anything terminated in group one, get terminated together etc.

Please do not twist solid core wire together, it's not the way to do it. Just terminate the groups together that belong together in a terminal block without twisting first.

 

[alex381]

Thanks for the replies.

You are right, a numpty did wire this house, but it wasn't me! I believe it was the previous owner trying to save a few quid.

PrenticeBoyofDerry: The white stuff seems to be dust, i've just noticed but on the left side of the picture there's a lovely bit just hanging down too Think i'll give it a hoover before I do anything else!!!

Chri5: Just to check regarding the red wires... I have a 4 block terminal. Three of the bays are for live, earth and neutral. In the 4th the instructions state that

"4th block provided for loop termination if necessary"

I'm a little confused what you mean regarding the groups, but if I put one red wire into one side of the 4th block and the other red wire into the other side, would this be ok?

Thanks,

Alex

 

[wingcoax]

As long as there is access to the JB for periodic inspection , yes that is ok.

 

[alex381]

Thanks wingcoax. I'll give it a go today.

Thanks for all the replies.

Alex

 

[riveralt]

Detailed instructions are given in wiki:

//www.diynot.com/wiki/electrics:lighting:rose

 

[PrenticeBoyofDerry]

Just to check regarding the red wires... I have a 4 block terminal. Three of the bays are for live, earth and neutral. In the 4th the instructions state that "4th block provided for loop termination if necessary"

I assume this 4 block terminal is part of the light fitting and not something you have purchased to tuck up in to the ceiling void?

You do have a looped in circuit, so what you must do is terminate conductors as so:
Un-sleeved black(neutral) to terminal point connected to the side of the blue flex. This is the neutral part of the circuit
Red sleeved black(switch live) to terminal point connected to the side of the brown flex. This is the live side of the lamp fitting.
The pair of reds to the loop terminal. One red is permanently live from the supply side, the other when terminated together feeds the permanent live to your switch and returns it to your fitting via the red sleeved black conductor when switch is closed.
Then the CPC (earth conductors) all together at the earth terminal.

 

[alex381]

PrenticeBoyofDerry: the 4 block terminal is part of the new light fitting yes. I have now wired up the light as you've described and it works perfectly

Riveralt: thanks for the link but it doesn't show how my new light fitting should be wired. I did have a look through the wiki, but couldn't find anything that helped with all my questions.

Thanks al

 

[ban-all-sheds]

However when it comes to the ceiling rose, this seems to be different. See the image below:

Apart from the pendant flex being the wrong way round, what you have is just like the last light in the very first diagram here: //www.diynot.com/wiki/electrics:lighting-circuit-layouts

The wiring clearly shows that the black wire with red sleeve (from the ceiling) is connected to the blue wire of the light. It also shows that the black wire (from the ceiling) is connected to the brown wire of the light. which is backwards!

It's AC.

However, the light switch is not upside and if ,when I put the new light fitting in, I follow the wiring from the diagram in the above link, the light switch will then be upside down (i.e. light will be on when in the switch is set to off).

PLEASE spend some time with these before you do any more electrical work:

• http://www.google.co.uk/search?q=electrical+circuits+101
  
  
• http://www.google.co.uk/search?q=multimeter+101
  
  
• http://kevinboone.net/electricity.html
  
  
• http://web.archive.org/web/20080213151445/http://www.kevinboone.com/domesticinstallations.html
  
  
• //www.diynot.com/wiki/electrics:books
  
  
• //www.diynot.com/wiki/electrics
  
  

 

[alex381]

BAS... thanks for your input and for implying I have absolutley no idea what i'm doing. I do understand that it is AC, but surely that's not a reason for ignoring wiring conventions?

The pendant flex is actually wired up the right way round to the ceiling rose as if you look under where the blue and the black with red sleeve cables are you can just about see it says "Neutral". Forgive me but I didn't think the black with red sleeve was neutral ... though I could be wrong as I'm clearly not an expert. My point was that, for my light and wiring, if the light switch is the correct way round, and the ceiling rose is wired as it states then when the light switch is in the off position the light will be on... which would imply the black with red sleeve was actually not the cable from the light switch.

 

[EFLImpudence]

So it is the rose which is incorrectly wired.
Just leave it as it is. It doesn't really matter - the wires can't read.

As for the switch - it is either on (closed) or off (open).
Turning it upside-down will not alter this.

The rocker may look off and on instead of on and off but it's the inside contacts which matter.

 

[ban-all-sheds]

BAS... thanks for your input and for implying I have absolutley no idea what i'm doing. I do understand that it is AC, but surely that's not a reason for ignoring wiring conventions?

No, but it does somewhat restrict the concept of "backwards".

My point was that, for my light and wiring, if the light switch is the correct way round, and the ceiling rose is wired as it states then when the light switch is in the off position the light will be on... which would imply the black with red sleeve was actually not the cable from the light switch.

I'll stop implying.

That's nonsense, and shows that you really don't understand some really basic stuff.

Which you must - doing electrical work without a full and genuine understanding of what you are doing and what's going on and how things work is a very bad idea.

Please spend some time learning before any more doing.