Lighting problem no lights now!

[ollieman]

I have the following lighting problem:

Took down an old pendant light fitting in the kitchen thinking it would be a straight forward to replace it with a modern light fitting with 3 spot lights.

There are two cables in ceiling, one I assume is the supply and the other going to the light switch (it appears to be the last in a run of lights), they each have black (Neutral) red (Live) and bare (earth) wires.

Using a connection block I wired the light fitting as follows:

The two red wires in the ceiling to the brown of the light fitting
The two black wires in the ceiling to the blue of the light fitting
The two earth wires to the earth of the light fitting. there was also an earth between the light fitting and the metal outer case which I also connected.

With all these connections made I reinserted the fuse for the downstairs lighting circuit. I went into the kitchen to turn on the new spot lights but it was already on (I am almost completely sure that the switch was off and thus the new spotlights should have been off). I then switched on the other kitchen light which is a fluorescent tube type light and the fuse for the lighting circuit blew.

All the lights had been working perfectly before. I un wired the new light and took it down, connected the two wires in the ceiling together as follows: red to red black to black and earth to earth in a connector block.
I attempted to replace the fuse (with standard 5amp wire, unused but old, from the 80's judging from the packaging) a few times but it kept blowing each time I turned power back on.

Needless to say:

• I have no downstairs lights
• Fuse keeps blowing
• What was wrong with the way I wired the new light fitting?

Please Help,

Ollieman.

 

[Iggifer]

you are going to need to do some testing, do you have a two-pole tester of any kind?

 

[ricicle]

How was it wired before - did you not take notes or a photograph ?

The two reds should be in a connector on their own. The black from the switch should go to the brown of the light. (it is important to know which black is which especially if the light has screw type lamps) It should be identified with red sleeving or tape.
The other black will go to the blue of the light.

By connecting how you did the feed from the mains was connected directly to the light hence it being on permanently and also the switch was connected across thsi mains cable so when you operated the switch you created a short across the L and N.

 

[scottyboyiow]

The two reds that you have connected to the brown in the light, one of these and one of the blacks is your switch line. Thus switching on the switch has shorted the line and neutral. As said you need to find out which red and black is your switch line, the two reds then go into a connector (if there isn't already one in the light fitting), the black of the switch line is then sleeved red and connects into the brown of the light fitting, the remaining black is your neutral and connects to the blue.

Edit: *Must type quicker

 

[vibrobullit407]

the way your light is currently wired will leave it permanently on due to the fact you have connected your permanent line and neutral to the lamp. You need to isolate the circuit, disconnect the conductors and using a multimeter test between black and red of each cable and switching the light switch. This will give you your switch line (black). Then connect the switch line (black with red/brown sleaving) to the brown of the light, connect the reds together with a connector and connect the other black to the blue. sleave the bare copper cores (cpc) with green and yellow sleaving and connect to the earth of the light.

This should fix your problem.

 

[ban-all-sheds]

• Go and learn how lighting circuits work, what switches do etc. //www.diynot.com/wiki/electrics:lighting.
  
• Resolve to think that not knowing how things work should be a good reason to not fiddle with them.
  
• And FGS grow a bit of common sense:
  
  

  Using a connection block I wired the light fitting as follows:
  
  The two red wires in the ceiling to the brown of the light fitting
  The two black wires in the ceiling to the blue of the light fitting
  The two earth wires to the earth of the light fitting.

  That's not how the various conductors were joined in the old light, is it.

 

[scottyboyiow]

Come on now BAS, doesn't everyone know someone who has tried to change a light fitting thinking it was easy, only to wonder why it does not work, 'even though I put the cables back exactly how they were'?

Ollieman, do as the other posters have said and your light will work fine. Remember to isolate the circuit at the Consumer Unit, not just at the light switch, and it may be of some use to you to buy a cheap multimeter so you can test and not get in this predicament again.

 

[ban-all-sheds]

Come on now BAS, doesn't everyone know someone who has tried to change a light fitting thinking it was easy, only to wonder why it does not work, 'even though I put the cables back exactly how they were'?

Quite possibly, but that doesn't mean it wasn't a dumb thing to do.

Firstly, despite knowing that you don't know how it works deciding to dive in anyway.

And secondly despite knowing that you don't know how it works deciding to take an arrangement of wires which is working OK and connect them together differently.

 

[ollieman]

Thanks everyone for the information, I'll rewire as suggested. Don't be too harsh on me (Ban all sheds) I've had the flu this week. Thanks again, I'll let you know how it goes.

Ollieman

 

[ollieman]

Thanks for all your help.

I followed your instructions and I have lights again! I'm going to remember to properly record how the lights were wired next time before do anything,

Cheers,

Ollieman.

 

[ban-all-sheds]

And please also learn how things work, i.e. what a switch does, and how therefore it can't possibly have line and neutral going to it, which conductors are which in a traditional ceiling rose etc.

This is not a dig - it's just that I passionately believe that people should genuinely understand what they are doing, not just be able to follow instructions to put-this-wire-in-that-hole without knowing why.

 

[riveralt]

And please also learn how things work, i.e. what a switch does, and how therefore it can't possibly have line and neutral going to it

I beg to differ - line and neutral can both be present at the switch and nowerdays seems to be getting quite common.

 

[ban-all-sheds]

They go to the enclosure, not the switch.

I meant it in the context of the original post - i.e. a single T/E cable with red and black going to a switch and being thought to be carrying line and neutral.

As we know, and the OP found out, when you make it so by connecting all the blacks together at the rose things don't go the way you hoped.

 

[ban-all-sheds]

That is a proper way to go about things.

Another proper thing to do is to not buy things from ledlightssell, because the business is run by thieves, liars and cheats.

They will steal from you, and if they do actually ship you anything the products will be rubbish.



anatomcreview is, like nearly all of his fellow countrymen, primitive and barbaric - scum of the earth really, like his whole nation.

We should restart the opium trade, and drug the whole stinking place.

 

[securespark]

Have you been drinking?