Bathroom Extractor Fan

[hil26]

Oh - forgot to add, the diagram is a direct copy from manufacturers instructions, I added the junction box to show it is not a loop system.

The only the thing the manufacturer does not show is where to take the yellow (switched live).

Thanks for your input and pointers

 

[ban-all-sheds]

Dear Ban all sheds

It amazes me that you think it won't work. IT DOES

Then it isn't wired up how you've drawn it.

Is that switch the existing light switch, or a new DP one that you've installed in order to control the fan?

 

[hil26]

its the existing switch, the pull cord is new as the original switch was on the wall

 

[hil26]

Quick question - how would you have wired it? Given the info in my drawing

thanks for your time

 

[brown-nought]

I think I've figured out how the old version worked.

Supply -> Switch -> Fan Live -> Fan -> Fan Neutral -> Switch Line -> Light _> Neutral.

I.e. they are wired in serial. Hence the fan goes off when the light goes off.

Does the fan work with no bulb?

 

[ban-all-sheds]

Oh - forgot to add, the diagram is a direct copy from manufacturers instructions, I added the junction box to show it is not a loop system.

Is it not? You have a cable coming in, and a cable going out - i.e. a loop. The fact that it's a JB and not a ceiling rose is irrelevant. If you look at these two it is plain that how the supply runs from one to another and how the live gets to and from the switch is the same:

The only the thing the manufacturer does not show is where to take the yellow (switched live).

I'm not surprised, given that they think their fan can work without a neutral....

Quick question - how would you have wired it? Given the info in my drawing

As the old saying goes - I wouldn't start from here..

You can't put the FCU after the switch, as then you'd need two - one for the switched live and one for the permanent live. If you're going to use an FCU, then you can either replace the switch with a DP one, and wire it as per the diagram in my earlier post, or you can change things so that the light and the fan both come off the FCU. In that case you'd need a second JB:

[Existing JB] -T&E- [FCU] -T&E- [New JB]

Move the light and switch cables to the new JB

Then use 3C&E to take the permanent live, switched live and neutral to a 3-pole fan isolation switch (which I note is missing from your diagram), and then to the fan.

Does the fan work with no bulb?

I can't wait to hear the answer to that....

 

[hil26]

I would like to thank you for your prompt and very knowledgeable replies

Ooooops - no light bulb - no fan

So will now look at wiring as previous posts

once again

thanks

 

[ban-all-sheds]

Ooooops - no light bulb - no fan

Dear God...

And you say that the manufacturers instructions told you to wire it like that?

And you never noticed that the light was now dimmer than before?

And you never noticed that the fan seemed a bit sluggish?

And despite being told you had it wrong, you insisted it was OK?

Like I said before, you really don't have a clue what you're doing, do you.

 

[hil26]

I am not too sure why your attitude in your last post was made in the tone it was -

Yes - the manufacturers instructions were as told previously,
No, I did not notice the fan was slow, as I had no idea as to how fast they are supposed to work
No- I did not notice the bulb was dimmer as it is a low wattage bulb and it did not look any different - daylight coming through window probably did not help

I would like to thank you again for the help/advise given,

 

[ban-all-sheds]

I am not too sure why your attitude in your last post was made in the tone it was -

Because of the feeling of utter incredulity that someone would ever think it was alright to wire a fan and a light in series.

And because you're working with electricity in a bathroom, and simply don't know enough to be doing that.

And also because of this:

Spur to be taken to pull switch which has
red - live
black - neutral
and an earth

Not unless it's a DP switch it doesn't..

Pull switch is wired as described
Black - neutral
Red - live
and has an earth

And guess what? That black wire at the switch is not a neutral, is it? See //www.diynot.com/forums/viewtopic.php?t=15782

Yes - the manufacturers instructions were as told previously,

Well - I suppose anything is possible, but my opinion right now is that they don't actually tell you to do what you did. Can you scan in any diagrams, or text, that have those instructions? Or tell us the make/model of fan - maybe the installation instructions are on their website.

 

[Damocles]

A fan should be wired from the ceiling rose bit. The main junction box where all the wires come together. You need a 3 core and earth wire. One for neutral. One for live. One for switched live. If you do not have a 3 core wire it is possible to use two 2-cores, but this adds to the confusion.

Live should connect to the live terminal at the junction. This probably has just red wires together.
The switched live should connect to the live retun from the light switch. This is probably a black wire (maybe with a red sleeve around it) which is connected to brown or red going off to the lightbulb.
The fan neutral should connect to the neutrals, probably a bunch of black wires which also connect to a blue or black going off to the light.

This cable should then go off to a 3 pole isolator switch. This is a switch which switches 3 connections at once. The idea is to completely switch off everything going to the fan.

After this switch, go on to the fan and connect to its terminals as shown.

I have not mentioned earths, but all cables should have an earth and these should be connected back to the junction box earth. Put green and yellow sleeving on the bare wire where it comes out of the cable. At the fan, bend back the end of the earth wire and completely sleeve it with some green and yellow pushed over it. The end bent into a loop should hold the sleeving on.

 

[ban-all-sheds]

Wrossurds - where are you going to put the FCU?

 

[Damocles]

Why do I need a FCU? this is coming off a 6A lighting circuit (I presume)

 

[hil26]

Suppose that will teach me not to be an unbranded product again.

Yes the black is indeed a "live" at the switch, it couldn't be anything else could it?

B-A-S Not to going to drag this on any more, as I have thanked you more than once for your help

Damocles - many thanks for a straight and concise description, yes its coming straight off the lighting circuit

 

[securespark]

If you do not have a 3 core wire it is possible to use two 2-cores, but this adds to the confusion.

I must point out here that Dam is not advocating the use of the earth wire as a current carrying conductor. This must never be done.