by ericmark »
Tue Jan 20, 2015 9:41 am
Years ago the ceiling rose was always used as a junction box to next light which was handy for emergency lights and ceiling fans. However there was often no neutral at the switch.
Use of 12 volt lights with power supplies has changed this and some houses now use the switch back box as a junction box as there are no ceiling roses. This however increases the loop impedance and one does have to be careful volt drop is not exceeded.
Without knowing the system used can't really give an answer. However in the main to add a light you go from an existing to new lamp and then from new lamp to switch there is not normally any connection between switches unless designed to use transformers and the like.
Years ago some two way lighting did borrow line but it caused radio interference and the practice was discontinued.
