End of Loop Ceiling Rose and Working out Switched Live


Postby Rlupton » Tue Jul 17, 2018 12:50 pm

Good afternoon all,

I am having a little trouble fitting a new light fitting to replace an old ceiling rose. The wiring in my flat is all old (black and red), but I have changed a few so far and all been fairly straight forward. However I've come to the last room and there are two of each wire (black, red and earth) rather than one in all the other rooms. I'm unsure which cable should go where, am I right in thinking one of the black wires is the switch live? If so is there a way I can work out which one it is?

Thanks for your help in advance.

photo5938066310384692448.jpg
Old cables


photo5938066310384692449.jpg
New light fitting
Rlupton
Rank: Labourer
Progress to next rank:
75%
Posts: 4
Joined: Mon Jul 16, 2018 8:13 pm

Sponsor

Simply Build It

Postby Mr White » Tue Jul 17, 2018 5:41 pm

You can either follow the cable run to see which one goes to the switch or use a multi meter.
If you haven't got a multi meter why not, do you use a knife to turn screws? You always use the correct tool for the job in this case you need a multi meter. (One can be had for less than £10)
Mr White
Rank: Foreman
Progress to next rank:
52.7%
Posts: 358
Joined: Tue Jun 20, 2017 9:54 pm

Postby Rlupton » Wed Jul 18, 2018 8:40 am

Thanks Mr White. One like this?

https://www.screwfix.com/p/lap-mas830b- ... 0wod8WcPaw

My other question being, once I have identified the switched live, how would the old wiring be arranged in to that new fitting?

Would I be right in saying the black switched live would connect to the brown live wire? Other black neutral to blue. Then earth to earth, then connect the red live wires together separately? Like pic below?

Wires.PNG
Wires.PNG (24.95 KiB) Viewed 258 times
Rlupton
Rank: Labourer
Progress to next rank:
75%
Posts: 4
Joined: Mon Jul 16, 2018 8:13 pm

Postby Rlupton » Wed Jul 18, 2018 9:29 am

Thanks Mr White. I thought that was what I would have to do. Like one of these?

https://www.screwfix.com/p/lap-mas830b- ... 0wodroEGMg

Once identified, does the switch live go to the neutral on the new fitting, as below?

Wires.PNG
Wires.PNG (24.95 KiB) Viewed 258 times
Rlupton
Rank: Labourer
Progress to next rank:
75%
Posts: 4
Joined: Mon Jul 16, 2018 8:13 pm

Postby Mr White » Wed Jul 18, 2018 5:55 pm

The meter you have linked to will be acceptable for the task you need to do. Lots of tutorials on youtube. You will soon wonder how you did with out it.

Yes the diagram is correct.
Mr White
Rank: Foreman
Progress to next rank:
52.7%
Posts: 358
Joined: Tue Jun 20, 2017 9:54 pm

Postby ericmark » Thu Jul 19, 2018 2:03 am

As you seem to have worked out, last one is easy, red to red and one black is neutral the other is switched line. With bayonet bulbs no real problem. With screw bulbs the centre pin needs to be line and screw neutral so some testing is required.
ericmark
Rank: Project Manager
Posts: 1970
Joined: Fri Oct 02, 2009 8:49 pm
Location: Mold, North Wales.

Postby Rlupton » Thu Jul 19, 2018 9:20 am

Thanks guys, now to buy and work out how to use a multimeter!
Rlupton
Rank: Labourer
Progress to next rank:
75%
Posts: 4
Joined: Mon Jul 16, 2018 8:13 pm

Postby Mr White » Thu Jul 19, 2018 4:28 pm

As I have said, there are lots of tutorials on YouTube. But "practice" elsewhere first, as electricity has no prejudices, it kills anyone.
Mr White
Rank: Foreman
Progress to next rank:
52.7%
Posts: 358
Joined: Tue Jun 20, 2017 9:54 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