Wiring extractor fan - can someone please explain?

shabbaranks · Joined: 04 Jan 2012 Posts: 82 Location: United Kingdom

Hi guys,

Appreciate I need to get someone in to do it - which they will be. Im just trying to understand how the wiring works. So we've got an extractor in the bathroom which I would assume is fed from the list live. The 3 core plus earth then runs to the pull chord and out again. Ive bought (which I thought would save the sparky doing it) a pull chord switch - 1 common L1 and L2.

Is it both lives (brown) to common both switched lives (grey wires) to L1 and neutral (black) to L2 and obviously earth to earth?

Thanks!!

EFLImpudence · Posted: Sun Apr 08, 2012 11:40 am

NO.

The neutral will not be connected to the switch and L2 will not be used.

What is a "list live"?

bernardgreen · Posted: Sun Apr 08, 2012 11:42 am

NO.

Live to Common and Neutral to L2 will result in a dead short between Live and Neutral, maybe immediately or when you operate the switch. That will take out your MCB ( or fuse ) and damage the switch.

Look at the Wiki for how switches operate and how to wire them, Then leave the work to the electrician.

handyman77 · Posted: Sun Apr 08, 2012 11:59 am

Just by the comment i know your thinking about doing yourself....
Its only a swtch right.....easy .....any muppet can do it! Not quite!
Just get the sparks in

shabbaranks · Joined: 04 Jan 2012 Posts: 82 Location: United Kingdom

I wish I could do it myself but unfortunatly I cant. But what I can do is learn how it works so I understand whats going on - which is what I am trying to do. Doesnt harm anyone, doesnt send my up in smoke so dont assume anything and it doesnt hurt to be curious... Any proper replies would be appreciated - thanks.

EFLImpudence · Posted: Sun Apr 08, 2012 8:55 pm

Can you see what is going on here?
(switch is not the same as yours but if you can work it out...)

Yellow disc = light
Blue = fan
Earth wires (cpc) omitted for clarity
SFCU = switched, fused connection unit
DP = douple pole, ie. switches two wires independently at the same time

More in the wiki - link at top of page.

ban-all-sheds · Posted: Mon Apr 09, 2012 9:04 am

shabbaranks wrote:

But what I can do is learn how it works so I understand whats going on.

Forget this specific example - it's too advanced for you right now.

Start here:

riveralt · Posted: Mon Apr 09, 2012 9:16 am

shabbaranks wrote:

Hi guys,

Appreciate I need to get someone in to do it - which they will be. Im just trying to understand how the wiring works. So we've got an extractor in the bathroom which I would assume is fed from the list live. The 3 core plus earth then runs to the pull chord and out again. Ive bought (which I thought would save the sparky doing it) a pull chord switch - 1 common L1 and L2.
Is it both lives (brown) to common both switched lives (grey wires) to L1 and neutral (black) to L2 and obviously earth to earth?
Thanks!!

The best way to learn is to ask the electrician who is going to fit it.
He/she will be able to see how the original was wired and sometimes why it was wired that way and explain the process to you.
We will be guessing here on the information you have provided and one thing you don't really want to do with electricity is Guess.