Fitting a Loft light

[dulciepreston]

Hi,

I’m in the process of installing 2 strip lights controlled by a separate switch in my loft. This switch will be connected to a ceiling rose on the stair landing. Anyway, I’ve connected the 2nr 3' strip lights in series back to the new switch.
My first question is what do I do with the loose earth wire within the switch? There is no earth point within the one way plastic switch so I’ve just capped it off into a terminal block, is this OK?
My second question refers to connecting the cable to the ceiling rose. I connected the live to the block where 4nr live connections are coming in and I connected the blue to the block with the 3nr connectors. I also connected the earth to the earth connector to keep things neat but this is probably unnecessary as the earth is capped off at the other end. I believe what I have done is correct but the CU popped when I switched the loft light on at the new switch.

Rather than muck about with my limited electrical knowledge I thought I'd contact the experts. Grateful for any advice on where I’m likely to be going wrong and thanks in advance for any assistance.

 

[AndyPRK]

The word series is wrong.


describe how you wired the switch.
What you should have done is join the black/blue supply wire straight through with a joining block to the lights.

And the red/brown to the switch terminals.

The earth should be connected through to the lights.

I understand there is a very good wiki/FAQ at the top of the forum covering all combinations. There are some nice diagrams in there.

 

[PrenticeBoyofDerry]

My first question is what do I do with the loose earth wire within the switch? There is no earth point within the one way plastic switch so I’ve just capped it off into a terminal block, is this OK?

It will also require to sleeved (green and yellow)

My second question refers to connecting the cable to the ceiling rose. I connected the live to the block where 4nr live connections are coming in and I connected the blue to the block with the 3nr connectors. I also connected the earth to the earth connector to keep things neat but this is probably unnecessary as the earth is capped off at the other end. I believe what I have done is correct but the CU popped when I switched the loft light on at the new switch.

Always connect the earth cables, as you will require continuity throughout the circuit, even if you have the switch earth not connected to plate or back box (both must be plastic to do this) you still require an earth at the fittings. This is not only to earth the fitting but also to help with testing procedures.
If the MCB/Fuse is blowing then you more than likely have a short circuit.
Check you are actually connecting to neutral and not switch live, also that no cable is damaged or shorting across in all connected accessories. This is were the earth cable comes in handy for testing,as it can test for continuity, polarity and insulation resistance, this will help break down the reason behind the fault. But you would then require the correct test equipment, which is always useful when doing electrical installations!
I personally would never take for granted that the earth (CPC) is continuous, even if visibly connected, I would always test.

 

[dulciepreston]

Thanks for the quick response guys.
Andy, pl let me elaborate..…
When I said I connected the strip lights in series I meant I connected the first unit as normal with the brown/blue/earth and ran the three wires from those same connectors to power the next light unit.
The one-way switch is wired using 1.5 t/e cable, with the live going to the COM, the blue going to the other terminal and the earth into a terminal block (as there is nowhere else to put it). The cable in turn then goes to the ceiling rose.
Hope that makes sense and shine some light as to where I’m going wrong.
Thanks for your on-going help.

 

[EFLImpudence]

When I said I connected the strip lights in series I meant I connected the first unit as normal with the brown/blue/earth and ran the three wires from those same connectors to power the next light unit.

That's in 'parallel', not series.

The one-way switch is wired using 1.5 t/e cable, with the live going to the COM, the blue going to the other terminal

Whoops.

(no earths shown but they must be connected together - as will the neutrals)

 

[ban-all-sheds]

The one-way switch is wired using 1.5 t/e cable, with the live going to the COM, the blue going to the other terminal

What are the blue and the brown conductors used for?

What do you think a switch does with, or to, the 2 conductors connected to it when you turn it on?

Hope that makes sense and shine some light as to where I’m going wrong.

Where you are going wrong is deciding to do electrical work even though you don't understand it. This time you've had an immediate indication that you have guessed wrong - another time you might end up creating a dangerous accident waiting to happen.

Please don't do any more DIY electrical work until you've learned about it.

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