Replacing a light switch???

Jon_01

Ok, so thought this would be a ten minute job!

I bought a 2 switch, light switch from B+Q mid week to replaces and existing unit. Took a pic of the inside wiring of the one there now and was sold a new one which the guy 'said' was the right one to replace with!

All good until I come to install.
The fitted one has 5 wires. 2 live(red), one from each of the lights (a blue and a yellow) and a neutral.

The new one has only 4 contacts. one for each of the lives and one for each switch... Do newer units not need a neutral? or am I missing something???

The unit controls 2 lights. One switch for each. No other switch for either light.

I'll add pic's below. . .

Jon_01

Wiring now;


https://photos.app.goo.gl/i9VUdNYZ6eAFrGvU6

Jon_01

New switch:

https://photos.app.goo.gl/6FH5qzouay4i16vD9

Owain_Moneysaver

The black isn't a neutral. It's a switched live.

On your old switch the two switches are opposite ways up. On the new switch they're the same way up.

Top left red is switch 1 COM, bottom left black is switch 1 1-way

Bottom right red is switch 2 COM, blue and yellow are switch 2 1-way and 2-way. At some point there must have been two-way switching for that light.

Rodders53

That black is a live to/from ceiling rose to switch one luminaire (probably the switched live)

The other is a 2-way switch with another switch to the second luminaire (hall/landing commonly).

Connect the yellow to 1, blue to 2 and associated red to COM on the rhs switch.

Connect red to COM and black (sleeved red) to 1 on the lhs switch to replicate the old switch wiring 100%. 2 is unused on that side.

TherealMandM

Its not a neutral, and if you do not know this then you shouldnt be messing with it...

Energize

matmidgley wrote: »

Its not a neutral, and if you do not know this then you shouldnt be messing with it...

This is what I was going to say, not knowing the difference between a live and a neutral wire and asking if an electrical circuit needs a neutral wire to work shows a lack of the most elementary understanding of electrical circuits and creates a liability for a dangerous installation.

Don't get me wrong I don't think it's unreasonable for people to replace switches and sockets in their home or even modify the consumer unit, but without the most basic understanding of electricity it's a dangerous undertaking.

Cornucopia

Moved to "In My Home"


As with all electrical installation threads, work should only be undertaken by a competent person.

TELLIT01

Many years ago a friend of my father removed a double light switch completely to make decorating easier! Came back from the pub rather worse for wear and decided to put the switch back on. He hadn't made a note of what went where and managed to blow up the main fuse box when he switched the light on. I do mean literally blew it up, flames coming out etc.

I suspect modern systems are less susceptible to that but it shows what can happen when you get electrical circuits wrong.

Coveredinbees!!!!

Don't forget to isolate the circuit at the fuse box before you touch anything, you can get a voltage detector pen fairly cheaply to make sure it is dead, for a tenner it's batter than you being dead. It should be tested on a known live circuit first.



On your existing switch the red and black on the left are from one light so move them to com and 1 on the left of the new switch, you will probably want it the same way up as the existing switch which is upside down. The wiring on the Right is for 2 way switching but there should be another switch somewhere which might have been taken out and they couldn't be bother to rewire the switch properly? The correct wiring would be red to com(mon) yellow to 1 and blue to 2. The wires are live and switch live so you can't really blow anything up. If the switch is backwards you can swap the blue and yellow over.


Or call an electrician.