Extractor Fan and light issues!

[bobthebuilder997]

I've just built a brand new bathroom. With advise I was told the simpliest way of wiring the extract fan and light to a pull cord (these are the only demands on this circuit) switch (maybe a double pole pull cord?) was to use lighting cable from the extact (which only had a L and N terminal (brand new)) to the pull cord switch (this has a N and L for 'supply' and a N and L for 'load'. I assume supply is from the consumer unit/fuseboard, and the load was the extract. I also want the pull cord to turn the light on and off at the same time the extract. I therefore have put the lighting cable from the ceiling rose into the 'load' terminals along with the extract cable.

Now once i restored the power the light comes on and off as it should, but the extract fan does do anything.....why not? Everything is brand new.

Thanks for your help in advance

S.

 

[ColJack]

how many terminals in the fan?
3?
you have probably bought a fan with a run on timer which usually needs a permanent live as well as the switched live.

if there is a L and SL terminal as well as the N terminal then just link L to SL..

 

[bobthebuilder997]

how many terminals in the fan?
3?
you have probably bought a fan with a run on timer which usually needs a permanent live as well as the switched live.

if there is a L and SL terminal as well as the N terminal then just link L to SL..

2 terminal the model is marley NDX100B definately only 2 terminal (there's a diagram on a PDF if you type the model in google.

Have I got the load and supply bit right, and does it sound like the circuit if described should work?

 

[tonyelectric]

You are correct, Load will be for your fan and the light, supply for the mains (ie from the consumer unit), so you will have a L & N into the supply and two each L&N out, don't forget to link the earth that should be present at the light and fan even if it is not required (in which case it should be taped up)

 

[bobthebuilder997]

You are correct, Load will be for your fan and the light, supply for the mains (ie from the consumer unit), so you will have a L & N into the supply and two each L&N out, don't forget to link the earth that should be present at the light and fan even if it is not required (in which case it should be taped up)

Thanks. So if what i've done is right -why is only the light working and not the extract?? The wiring diagram on http://www.marleyplumbinganddrainage.com/diyer/download/674/NDX pre-fixed fans.pdf seems to be different?? does this matter - should both work equally well? I've nicely tiled around the extract, so to remove it will be very annoying! my mistake I should have tested it properly first. Any advise on how to find the fault?

Thanks

S.

 

[riveralt]

Thanks. So if what i've done is right -why is only the light working and not the extract?? The wiring diagram on http://www.marleyplumbinganddrainage.com/diyer/download/674/NDX pre-fixed fans.pdf seems to be different?? does this matter - should both work equally well? I've nicely tiled around the extract, so to remove it will be very annoying! my mistake I should have tested it properly first. Any advise on how to find the fault?
Thanks
S.

From your description you haven't wired the fan up as per the instructions you have quoted - the basic fan - consequently you do not have a complete circuit. You have also made no mention of a fuse in the circuit - can be part of the double pole switch.

You need to interupt the lighting circuit with a fused dual pole isolator. From this run the line to the remote light switch and from this the switched live goes to the line at the light and then onto the line at the extractor fan. The neutral from the dual pole isolator goes to the neutral at the light and then onto the neutral at the extractor fan. This will ensure that when the light is switched on or off the extractor fan does the same.

 

[bobthebuilder997]

//media.diynot.com/157000_156082_29310_91695113_thumb.jpg

Does anyone think this will work?
Help is much appreciated.

Thanks

S.

 

[bobthebuilder997]

WC Fan and Extract sketch

• bobthebuilder997
• 23 Dec 2010
• 1

 

[riveralt]

WC Fan and Extract sketch

• bobthebuilder997
• 23 Dec 2010
• 1

What is the size of the fuse that is protecting the lighting circuit? According to the MI if you have a 5amp MCB or similar then you do not need to introduce another fuse in the circuit. If it is not a 5Amp then...

Interupt the lighting circuit with the fused dual pole isolator (in otherwords swop your dual pole pull switch for the isolator). Put the pull switch in place of the isolator and link the pull switch line to the live pendant (call it switch live) at the lights and the neutral to the neutral loop at the ceiling rose.

At the fan connect a t&e to the live and neutral and run them back to the ceiling rose. At the ceiling rose the live (brown) goes to the switch live and the neutral goes to the neutral loop.

You don't need your blue or green coloured wires you have drawn.

 

[Taylortwocities]

The isolator switch is meant to isolate only the fan. In your diagram it will turn off both the fan and the light.
The idea is that you will need the light to be on while you maintain the fan.

So, wire the fan to the isolator(Load side)
The light goes to the pull switch, or to the isloator (feed side).

 

[riveralt]

The isolator switch is meant to isolate only the fan. In your diagram it will turn off both the fan and the light.

I agree TTC but the MI basic fan instructions state that is how it should be.

 

[bobthebuilder997]

Can anyone draw me a diagram please????

The MCB is a 6 by the way.

Thank you so much.

S.

 

[riveralt]

Can anyone draw me a diagram please????

The MCB is a 6 by the way.

Thank you so much.

S.

Basic Extractor fan

• riveralt
• 23 Dec 2010
• 1

This diagram follows the Manufacturers instructions for the basic fan given your situation. You could leave out the dual pole pull switch and use a switched fcu instead.

The next diagram does not follow the MI but allows you to isolate the fan while leaving the light available.

Basic extractor fan with isolator after the lamp

• riveralt
• 23 Dec 2010
• 1

 

[bobthebuilder997]

Thank you Riveralt.

I'll give it a go. But I don't see the point of the isolator??

S.

 

[riveralt]

Thank you Riveralt.

I'll give it a go. But I don't see the point of the isolator??

S.

The Dual pole fused connection unit isolator protects the circuit wires and also allow you to conduct maintenance on the fan and/or light in the first diagram.

Why you have to introduce a 5amp fuse into a circuit already protected by a 6amp mcb is open to debate.