2 Gang Switch and Bridge Connection
Posted: Fri Aug 31, 2018 9:12 pm
by Dave999
I've recently moved in to a new house. The upstairs light is controlled from both upstairs light switch and downstairs switch. The loft has a light fed from the upstairs light switch but that switch (1 of 2 gang) has no live feed or neutral return. I've attached an image to explain. I have a multimeter (set to auto on AC) but have no idea which terminals to use and what exactly I need to do. Can someone please tell me how to "liven up" the right switch from the left switch. If it helps the right switch goes into the loft and straight into a bulb fixure. I have a feeling I need to bridge the connection(s) but no idea which. In the diagram I'm using an educated guess on which are the main cables go for the Hallway light and the downstairs switch. Thanks for any help anyone can give.
Re: 2 Gang Switch and Bridge Connection
Posted: Sat Sep 01, 2018 10:02 am
by Mr White
In order for anything electrical to operate it requires a live and neutral (Also earth for safety)
In the UK most lighting circuits feed the ceiling rose then loop down to the light switch, this means that there is no neutral at the switch, so you can not supply another light from the switch.
People do not understand this, and are of the opinion that because the cable has a black and red or brown and blue it must be live and neutral, if this were the case it would mean as soon as you operate the switch there would be a bang as you have just connected live to neutral. In truth the black or blue should be "tagged" with either coloured sleeving or tape to indicate it is actually a switched live, not a neutral.
In order to make your new light work you should take the supply from a working ceiling rose.