Can anyone make sense of this lighting wiring? >>

[TheNibbler]

Hi

My lounge lights, one switch controls 2 separate lights. First light had the simple positive, neg and earth arrangement, I installed a new Ikea light there and it works fine, I went to do the second light and wow...

Please see the picture>>
http://imgur.com/qOVbxT5

There's 2 white wires and an earth going to the choc box thing and it seems only the earth is actually connected to the light. I have no idea how to wire up my new light.

Someone told me the white wires mean its on a loop so doesn't matter which one I put put in the positive and negative terminals on the new Ikea light fitting, but I'm reluctant to try that.

Hope you guys can see it clearly from the picture, any ideas how to wire up the new light?

Thanks for any feedback, its a great forum, used this place a lot to do my flat up

 

[riveralt]

From the picture terminal block left to right.
The black(red sleeve) and red wire are your switch live - on the lamp the live wire connects here.
Second from left - earth - NOTE one of the earths is not properly connected - that needs fixing. Connect any lamp earth here.
Third from left is your neutral - you lamp neutral connects there.
If the Ikea lamp doesn't distinguish between live and neutral then you can put either wire in the first left and third from left.

 

[rjm2k]

It's not positive and negative, it's live and neutral. You do realise that those blocks go through from one side to the other?

The leftmost pair have a black (covered red) which will be the switched live, plus the red which will go to your other light. On the other side of the block they are feeding the "live" white wire for this lamp.

Next pair is your earth loop in, out and one going to the other lamp (should be in the same grey as the live to the other lamp) note that one of the 2 which share the green yellow sheath is not connected properly.

The next pair has a Black Neutral which comes in and loops back out as another black neutral, it's difficult to see but I suspect there are 3 black wires going into that part of the block, 1 loop in, 1 loop out and another to the other light (should be in the same grey as the live/earth to the other lamp). On the other side of the block the white "Neutral" goes to the lamp.

Next is the 3 lives, one loop in, one loop out and 1 going to the switch which shares the same grey as the red sheathed black wire in the very first block.

All fairly standard

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

If all you need to do is change the lamp, just disconnect the whites and the lamp earth from the bottom of the block and reconnect the new one with brown (live) to the leftmost and blue to the 3rd where the white wires are now, plus the earth.

Make sure you turn off that circuit as the consumer unit and verify it's off since there will always be live in there even if the light switch is off!

 

[bernardgreen]

From left hand side of the four way terminal block

Black with red sleeve. Switched live from switch
Red Switched live to other lamp

Green/ yellows Earth

Blacks Neutrals. one from fuse box, one to the other lamp, one to the ceiling rose in the next room

Reds Lives. one from fuse box, one to the switch, one to the ceiling rose in the next room ( LOOP )

The four way terminal block is used as it is large enough to take all the wires while the one supplied in the fitting is too small and being three way does not have the LOOP terminal.

The white wires come from the lamp holder and woud have been in the three way block when the fitting was bought. Someone moved them to the switched live and neutrals in the four way to save having to connect two wires between the four way and three way blocks.

 

[ban-all-sheds]

First light had the simple positive, neg and earth arrangement,

It's not "positive & negative".

http://www.bbemg.ulg.ac.be/en/general-information/electric-magnetic-fields/electrical-concepts.html


When you have a few moments:

• http://www.google.co.uk/search?q=electrical+circuits+101
  
  
• http://www.google.co.uk/search?q=alternating+current
  
  
• 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
  
  

it seems only the earth is actually connected to the light.

Not very well - you must re-make that dodgy connection where the earth wires come in from the top - it's entirely possible that a section of your lighting circuit is unearthed. You should check every light fitting and switch to make sure that the buffoon who installed that light hasn't laid other deadly traps for you elsewhere.

I have no idea how to wire up my new light.

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

Someone told me the white wires mean its on a loop

Don't take electrical advice from that person.

so doesn't matter which one I put put in the positive and negative terminals on the new Ikea light fitting, but I'm reluctant to try that.

Generally it doesn't, as it's AC it will work fine. If the light takes lamps with a full-size screw base then there's a safety advantage in wiring it so that L goes to the centre contact and N to the screw - stops you accidentally touching a live part if you go around changing bulbs with it live.

Doesn't the light tell you which is L & N?


But really, if you are going to do electrical work you should learn about how it all works - apart from the dodgy earth connection that wiring is exactly to be expected, not "wow" - the black switched live even has a bit of sleeving on it, which is often missing. FGS don't let that drop off - that black is NOT a neutral wire, and you have to keep track of it, and not end up connecting it to the other blacks.

 

[TheNibbler]

Excellent, thank you so much for your help chaps!

I'm pretty clear what I need to do now. So it's neutral not negative... Got it!

The new ikea light does indeed have the terminals clearly labelled, I had no problems installing the first light.

I thought when confronted with extra box on the 2nd light I'll just hook it up "like for like" as the old fitting (also ikea) but I didn't understand the 2 white wires (and why they're not even connected to the box).

So am I right in saying that 2nd smaller chic box is redundant and can be removed? Left white wire into my new lighting fitting as Live. Earth to Earth and the right white wire into new fitting as Neutral. That correct?

Is it bad practise to use those white colour wires or should I replace them with red and blue wires?

Regarding the dodgy earth situation I did notice a few weeks back when changing a flickering soon to die bulb that when I touched this bulb the good one on the other light would flicker... That normal?

Once again thanks for your help guys.

 

[TheNibbler]

To make it crystal clear.. is the following diagram correct?

http://imgur.com/aLwQkjF

 

[Taylortwocities]

Yes

 

[PrenticeBoyofDerry]

keeping common to your existing wiring colours would be recommend,
So red switch live, black neutral and yellow/green sleeve for earth not just yellow.

 

[rjm2k]

So am I right in saying that 2nd smaller chic box is redundant and can be removed?

It's not redundant on the existing light as it's connected to a metal tab on the metal fitting, thus earthing it. It probably came with the fitting and your new one will probably have something similar so in that sense is probably no longer needed.

Left white wire into my new lighting fitting as Live. Earth to Earth and the right white wire into new fitting as Neutral. That correct?

Is it bad practise to use those white colour wires or should I replace them with red and blue wires?

The white wires most probably came with the fitting, your new fitting will have replacements.