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bathroom extractor fans (Read 5852 times)
spongebob
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bathroom extractor fans
Dec 18th, 2004, 11:20pm
 
I've installed a couple of replacement extractor fans with timer and linked to light switch in the past, but always with the benefit of using the existing wiring. I seem to remember a switched live being used on them. I'm wanting to fit a fan in my own bathroom so I took the cover off a friends fan today to jog my memory. There was only a live and neutral to be seen. Has the wiring for these fans changed or am I missing something? ???
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LSpark
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Re: bathroom extractor fans
Reply #1 - Dec 18th, 2004, 11:24pm
 
That one must only come on when the lights on, usualy you have a switched live and a permanent live and so when the light is switched off the fan runs on timer until time duration is up  Roll Eyes
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« Last Edit: Dec 18th, 2004, 11:25pm by LSpark »  
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The_Trician
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Re: bathroom extractor fans
Reply #2 - Dec 18th, 2004, 11:25pm
 
Its sounds like your mate's fan doesn't have a timer fitted.

The timer needs what is known as a 'permenant live' to run. This can be picked up from the 'common' terminal of the lightswitch.
If there's only a live and a neutral, then its my guess that the fan you looked at doesn't have a timer.

TT
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spongebob
Re: bathroom extractor fans
Reply #3 - Dec 19th, 2004, 12:56am
 
Guys...I agree with what you say and therein lies the problem. The fan does come on with the lights but it is also timed. No sign of an extra core anywhere. I'm baffled to say the least. I picked up a brochure for a "Aircon" fan recently that gave the impression that all you needed was a live and a neutral for the fan and timer to run but this was not one of those fans. it's a bit of a mystery! ???
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LSpark
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Re: bathroom extractor fans
Reply #4 - Dec 19th, 2004, 1:47am
 
There’s many possibilities

The earth may have been used as a live conductor, and since most fans don't require Earthing this is a possibility.

Another is that you may have a hidden cable that is not visible, did you look directly at the connections to the fan?

The former seems to be the most likely
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spongebob
Re: bathroom extractor fans
Reply #5 - Dec 19th, 2004, 11:44pm
 
ah! Can't remember if there was an earth wire or not. Maybe I'll pay him another visit, although twice in a year, he may think I'm after something. 8)
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LSpark
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Re: bathroom extractor fans
Reply #6 - Dec 20th, 2004, 12:09am
 
Yep, check it out, I think you might be surprised  Smiley

hopefully not in for a shock so becarefull  Wink
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« Last Edit: Dec 20th, 2004, 12:09am by LSpark »  
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molerat
Re: bathroom extractor fans
Reply #7 - Dec 21st, 2004, 8:47am
 
Or, as in my bathroom fan, the timer is a seperate external unit  Wink
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supersparky
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Re: bathroom extractor fans
Reply #8 - Dec 21st, 2004, 12:35pm
 
i wouldent bother mate

just wire it in 3 core and earth

its what we do as standard anyway, because if you change your mind you have that extra core

from lighting rose, to an isolator by fan/ above door outside (see zones)

to the fan

if you dont need the third core chock block it

8)
ss
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tellondon
Re: bathroom extractor fans
Reply #9 - Dec 21st, 2004, 7:54pm
 
It could be a extra low voltage fan that are commonly used in bathrooms, it would have the timer control located elsewhere, perhaps in the loft?
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spongebob
Re: bathroom extractor fans
Reply #10 - Dec 22nd, 2004, 12:02am
 
Thanks for all the replies. Fan dilemma is being put on hold until other matters are sorted. Smiley
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