A Few Basic Questions Around Light Fittings


Postby mth » Sun Nov 20, 2016 3:26 pm

I had recently a rewiring done and finally wanted to replace the temporary bulb fittings with proper ceiling lights. There are a few things though I would like to be sure about:

1. In some of the room my expected 3 cables come from the ceiling. In others though, it is way more, the existing fitting looks like this:
Image
Why is it like that and how does it need to be connected exactly?

2. The electrician who rewired left a few cables painfully short, it is nearly impossible to connect it to the luster terminal provided by the light. I think about using Wago connectors to extend the cable:
http://global.wago.com/en/products/product-catalog/terminal-blocks-connectors/installation-connectors/lighting-connectors-224-series/index.jsp. Is it recommendable?

3. One ceiling lamp is imported and does not have an earth cable although it is metal. Is it enough to just connect a cable from the earth wire of the rose to the metal hull of the lamp?
The cables of the lamp don't look double insulated and there are no additional information or labels, it looks like this:
Image
Image

Many thanks for any help
mth
Rank: Apprentice
Progress to next rank:
31.6%
Posts: 11
Joined: Tue Nov 04, 2014 8:59 pm

Sponsor

Simply Build It

Postby kbrownie » Sun Nov 20, 2016 7:10 pm

your images, I cannot see.

But it is not unusual to have more than the standard three sets of cables on a loop-in set up. There will be likely other equipment it is supplying that can be taken from the light circuit (fans, wall lights, shaver points, heating controls, security and fire/smoke alarms etc..)

It is extremely wise to earth metallic fittings that are not passed as double insulated.

And yes cables can be extended by insulated connectors, providing the terminal/connection stays within the enclosure and is protected against accidental contact to non-insulated parts.
kbrownie
Rank: Project Manager
Posts: 1995
Joined: Mon Mar 05, 2007 9:36 pm

Postby mth » Sun Nov 20, 2016 8:19 pm

Many thanks for your reply. To avoid confusion, here are links to the pictures again:
ceiling rose:
https://drive.google.com/open?id=0B5hJCFfDddTSd1UtcjdrZlNmNkU
cable of metal lamp:
https://drive.google.com/open?id=0B5hJCFfDddTSc3RuQmdfN0czMWM
mth
Rank: Apprentice
Progress to next rank:
31.6%
Posts: 11
Joined: Tue Nov 04, 2014 8:59 pm

Postby kbrownie » Sun Nov 20, 2016 10:37 pm

Ceiling rose looks like it is the end of a loop, with just the incoming live conductors and the switch lines. Very normal, I was expecting more with regards to your original post! The central two browns are the live loop. The two light blues are the neutral loop and the remaining brown is the switch line/live.
Green/yellow CPC/earths.

The cable to the metal fitting would not satisfy the requirements for class I metallic fittings.
kbrownie
Rank: Project Manager
Posts: 1995
Joined: Mon Mar 05, 2007 9:36 pm

Postby ericmark » Thu Nov 24, 2016 11:00 pm

I also have metal fittings with two core cable and no double square to show double insulated. I swapped the standard ceiling rose for a type with slide in hook so whole lamp can be wired on the floor the lifted up and slid into position. The hook is earthed but it's unlikely the chain would give good earth continuity. So I have just taken a chance. I think any fault will likely trip the RCD. Also the cable is double insulated i.e. a sheaf on the two wires.
The cable you show seems to have no sheaf, so would expect the whole fitting to be earthed.
ericmark
Rank: Project Manager
Posts: 1825
Joined: Fri Oct 02, 2009 8:49 pm
Location: Mold, North Wales.

Postby mth » Fri Nov 25, 2016 2:43 pm

Many thanks for your helpful replies. As a last question, can you recommend a source to understand better how (and why) a ceiling rose that is "end of the loop" needs to be wired together?
mth
Rank: Apprentice
Progress to next rank:
31.6%
Posts: 11
Joined: Tue Nov 04, 2014 8:59 pm

Postby kbrownie » Fri Nov 25, 2016 6:38 pm

You have a source the qualified electricians on here.
There are number was to make a light work by the operation of a switch.
You can loop in both live and neutral in at the light fitting, you can also loop them both in at the swicth, you could alternatively loop just the live in at light and the neutral at the switch or visa-versa.

Then there are other methods using junction box arrangements.

Providing you have a neutral and a switch line at the light fitting and a common/perm live and a switch line at the switch. They will come on/off.

Obviously it would be good/safe practice to have the circuit earthed,
kbrownie
Rank: Project Manager
Posts: 1995
Joined: Mon Mar 05, 2007 9:36 pm

Postby mth » Sun Nov 27, 2016 3:35 pm

Hi KBrownie,

thanks for your answer. I am not sure if I expressed myself well. I do trust the recommendation of the qualified people around here. But I still do not understand the setup and how the wiring should be done. I would like to learn though.

In very amateurish words: I have a lamp that expects three wires, Live, Neutral and Earth. Out of the ceiling come twice as much. As it seems, all of the cables are connected to the light, which means I have to connect several from the rose to just one each in the lamp. What is the rule to do that correctly?

I don't want to just blindly try to copy what I see with the installed light atm, but rather to understand why the cables are connected the way they have to.


Many thanks
mth
Rank: Apprentice
Progress to next rank:
31.6%
Posts: 11
Joined: Tue Nov 04, 2014 8:59 pm

Display posts from previous
Sort by
Order by



  • DIY How to Project Guides

  • DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!



 


  • Related Topics