Timed bathroom extractor fan (again)!

[bradley_stoker]

Firstly, may I apologise for dragging this subject up again when there are some excellent postings already on this site, but.........

I was planning to install a timed shower extractor this week end. I understand the need for the four wire connection (permanent live, switched live, neutral and earth).

I will take the feed from an adjacent ceiling rose for permanent live, neutral and earth and the switched live from the bathroom pull cord light switch.

So far so good. (I hope)

This would then give me a fan that came on with the light, and stayed on for a timed interval.

I then planned to introduce a further three pole pull cord switch into the circuit so that I was not disturbed in the night if the ensuite loo was used.

My local B&Q electrician has never heared of a three pole pull cord.

Questions

a) does my plan above make sense?
b) Would it be ok to wire the scheme without the isolating three pole pull cord and introduce one at a later date if I can find one

or c) would it be ok just to switch the permanent live with a single pole pull cord or is this stacking up safety issues for future maintenance.

many thanks once again

Bradley

 

[breezer]

I then planned to introduce a further three pole pull cord switch into the circuit so that I was not disturbed in the night if the ensuite loo was used.

neither have I

I would not bother, since as its an en suite, fans also get rid of smells which may be worse (and yes i am being serious)

 

[seehig]

why not install your timer fan properly,that is via a triple pole fan isolater switch!!...then switch it off when u go 2 bed... magic

 

[bradley_stoker]

The problem is that if I use a three pole wall mounted isolator switch I will have to chase out and damage decorations in my bedroom....when I could achieve the same by using a pull switch accessed from the loft.

But otherwise my understanding is sound??

regards

Bradley

 

[plugwash]

you can get fan isolator pull switches, you probablly won't get them from the diy sheds (and btw DO NOT take thier advice on electrical stuff)

TLC have one but its not particularlly cheap http://www.tlc-direct.co.uk/Products/ASCS3PIF.html try some local wholesalers first.

 

[securespark]

That's cheaper than they were when introduced. As a trade customer, I paid 14 quid for my first one of those!

You must fit a triple pole isolator. Where you fit it is up to you, but it should be easily accessible.

Why don't you take your supply from the ceiling rose entirely? it would save farting around with two seperate runs.

Some of my customers use the triple pole to isolate the fan at night, but of course, it has to be accessible.

Breezer, hope you weren't suggesting to do away with a TPI switch.......tut, tut!!

 

[bradley_stoker]

Thanks securespark...but this is where thirty year old A level physics starts to let me down!

If I take the feed from the ceiling rose, what triggers the fan to start??

cheers

Bradley

 

[securespark]

The switched live from the rose.

Or are you saying you only have switched live and no live loop at the rose?

 

[bradley_stoker]

Ahh I get your drift now, still painting downstairs...not been in loft to look.

I think that there is no live loop in the pendant fitting, so I was anticipating connecting into the live side of the switch for the permanent live and the switched side for the other.

Does that sound OK??

cheers

Bradley

 

[plugwash]

usually (unless its wired in singles) there will be some place (either the switch,the rose or a junction box depending on how things are wired) that has all the connections you need together. the neatest and most common method is to use a peice of 3 and earth to pick up everything from there.

 

[bradley_stoker]

Many thanks

I will go up and have a look....I can always get the mechanical installation complete and then find a TP pull switch when the decent places open.

Bradley