Loft light

[thomo27]

Im looking to add a light to the loft. Am I ok to wire the T & E cable into a existing Junction box which is practically next to the beam where I intend to pu the switch ?

 

[Lectrician]

No, you must take it right back to the consumer unit, taking it past the garden shed and greenhouse first.




Seriously - yes, aslong as it is a joint box on the lighting circuit. If it is a joint box supplying a switched fitting, make sure you connect to the permenant live and not the switched live.



The fact you ask this question makes me wonder how competent you are to undertake the task. Do you know what size cable touse, and where to run the cables from and to? It is usual to take the neutral tot he loft switch as it makes for a shorter cable run.......but DIYers sem to make a meal out of having a neutral to play with at a switch.......

 

[thomo27]

2.5MM squared cable , please correct me if im wrong but was going to connect L N & E to the junction box then L to Common on the switch , E to the switch and N to the lamp with the switch live and another E

 

[davy_owen_88]

2.5MM squared cable , please correct me if im wrong but was going to connect L N & E to the junction box then L to Common on the switch , E to the switch and N to the lamp with the switch live and another E

Ummm.. ok, here come the corrections:

Assuming the junction box is fed from the lighting circuit you only need 1.5mm^2 cable. (You can find if its fed from a lighting circuit if you trace the cables going from the junction box to a light fitting/switch)

You will need to:

Run a length of t&e from the junction box you intend to take your feed from and take that to a new 4 terminal junction box. Connect L N & E to 3 of the terminals in the junction box.

Take a length of t&e and connect the live conductor to the live terminal (fed from the previous junction box - permanent live) and connect the neutral to the unused terminal in the junction box (mark the neutral conductor with a brown sleeve at both ends to indicate that it is a switched live). At the other end connect the live to common and the neutral to L1 (and connect earth to the earth terminal at the switch if it has one)

Then take another length of t&e and connect the live conductor to the switched live terminal (the one from L1 of the switch) and connect the neutral and earth to their respective terminals (ensuring you don't mistake the switched live for neutral at the junction box hence the importance of the brown sleeve).

(Ignore 'Supply to next light').

Davy

 

[Sarahspark]

I would agree Lectrician that the easiest way is to take the lighting feed to the switch, join the neutrals together in a connector, earths together in the terminal at the back of the pattress and obviously switch the lives

 

[Spark123]

Like this?:

(Ignore 'Supply to next light').

 

[thomo27]

thanks 4 your help, just to recap, as it stands I have L which will go to C on the switch , E to the back of the switch and N (which at present has the other end in the 4th terminal of the Junction box not connected to anything ??) is tho incorrect , ami right in saying the N is the switched live that goes to L1?

 

[Spark123]

Using the JB method the blue in the switch cable is switched live, not neutral. It should be sleeved brown at both ends to indicate it is a live (phase) conductor.