New light - loop in

[AS]

Am I right in saying that if I have an existing light being fed from an old junction box system I can make a loop in connection from this exisitng ceiling rose - By running a cable from old ceiling rose to the new light ceiling rose and take the new switch cable from the new ceiling rose. If i then add another switch for two way switching i run a 'strapping 'cable between new switch 1 ( cable coming from new rose) and new switch 2.

Can I also if necessary run the new switch cable to an existing 2 gang switch (these 2 lights on junction box circuit) and change to a 3 gang switch ( 2 gang being the exisitng ones and the 3rd gang being my new loop in switch?

 

[breezer]

no

 

[brown-nought]

I think I follow.

1) If you have a JB system you may only have a switch L&N+E running to the rose. You need a perm live.
2) Strapper is 3c+e - follow ref section.
3) Change to 3G depends on if you can get the cable to the switch without damaging existing cable. Also best practice is to ensure all 3 are on the same circuit. check you can get the cables neatly into the back box as well.

 

[AS]

Does this mean that to add in a light I need to continue with junction boxes.

As i have most of the house as a building site and lights seem to be in old bakelite junction boxes with earths connected on the outside - would i be best to get lighting cicuit rewired?

 

[breezer]

sorry i forgot to elaborate.

i said no because if jbs have been used then there will only be switched live and neutral at the rose, where as you obviously want L Sw L & N

(i missesd the e on purpose)

but if its using jbs, is there an earth?

 

[brown-nought]

Sometimes that's quicker than making good the old mess.

You can switch between the two systems provided you supply a perm live from the JB to the first loopin rose.

When you mix systems though it is vital to check you have earth continuity and the neutral is dedicated to the lighting circuit.

 

[breezer]

as you said

Sometimes that's quicker than making good the old mess.