Fitting a bathroom fan...again.
- Thread starter amfisted
- Start date
Sponsored Links
Junction boxes are best avoided where possible.
If your having it triggered off the light then just run 3 core and earth from the light to fan.
If your having a switch for just the fan use 2 core and earth between fan and switch.
If your having it triggered off the light then just run 3 core and earth from the light to fan.
If your having a switch for just the fan use 2 core and earth between fan and switch.
Sorry, again I'm a little confused--the instructions say that the fan doesn't need an earth connection. I wouldn't be having the fan triggered by the light, but I would of course be powering it from the lighting circuit. Why would I need twin and earth?
Because the regulations require that a circuit protective conductor shall be run to and terminated at each point in wiring and at each accessory except a lampholder having no exposed-conductive-parts and suspended from such a point.
It's to provide protection in the cable, and to allow a different, or another, item to be installed where the fan is which does need an earth.
Why would you want to not use T/E anyway?
It's to provide protection in the cable, and to allow a different, or another, item to be installed where the fan is which does need an earth.
Why would you want to not use T/E anyway?
Sponsored Links
Its not that I don't want to use it; I suppose its because with the appliance not requiring an earth I've become fixated with using two core cable only.
If regulations require it, then twin and earth is what I'll put in.
Given that, would it therefore be best to fit a triple pole isolator rather than a double?
If regulations require it, then twin and earth is what I'll put in.
Given that, would it therefore be best to fit a triple pole isolator rather than a double?
As you've been told, that's definitely what the regs require. You will have to find some safe way to terminate the CPC (earth) conductor at the fan end (don't cut it short - in case it is needed in future). If the fan has no earth terminal, you could use a small piece of connector block. The bare CPC/earth wire obviously needs to be sleeved with a little green/yellow sleeving.
Were you thinking of switching the earth/CPC? If so, that is never allowed - only switch the live/line and the neutral. 3-pole isolators are for when you have 'permanent live' as well as a 'switched live' (and neutral), which is the case, for example, with timer fans.
Kind Regards, John
The use of a cable with an earth core is irrelevant to 2-pole/3-pole isolation, as the earth must never be switched.
If the fan has permanent as well as switched live you use a 3-pole isolator. Assuming you are fixated with having an isolator in the first place.
[doh!]My turn to be too slow.[/doh!]
If the fan has permanent as well as switched live you use a 3-pole isolator. Assuming you are fixated with having an isolator in the first place.
[doh!]My turn to be too slow.[/doh!]
OK, so let me get this straight once and for all, and thank you for your patience. Its a timer fan, so I fit a triple pole isolator between supply and fan to isolate live, switched live and neutral, and safely terminate the earth but don't cut it short in case its needed in future. I take it the isolator is required to allow maintenance in case the fan develops a fault?
The pull cord switch has L1, L2 and Common terminals. To which two of these terminals should the switched live be connected?
Thanks again.
The pull cord switch has L1, L2 and Common terminals. To which two of these terminals should the switched live be connected?
Thanks again.
Yep, that's about it - and that is the reason way some people favour having such isolators. The instructions which come with fans often demand an isolator - and, at least for the time being, regulations require that one obeys such instructions!
The live feed should be to 'Common' and you can use either L1 or L2 for the switched live output. Is this pull switch just for the fan, or also the light (timer fans after often wired to come on when the light is switched on)? If the former, were you planning to put the pull switch before or after the isolator?
Kind Regards, John
Thanks again, John.
The pull switch is just for the fan, and I plan to fit it after the isolator. I didn't want to wire the fan to the light because there's plenty of natural light in this bathroom and a lot of the time electric light would be unnecessary; unlike in our last house where the bathroom was on the gable end of a Victorian semi and only had a tiny window.
The pull switch is just for the fan, and I plan to fit it after the isolator. I didn't want to wire the fan to the light because there's plenty of natural light in this bathroom and a lot of the time electric light would be unnecessary; unlike in our last house where the bathroom was on the gable end of a Victorian semi and only had a tiny window.
Yes, its me again on the same old topic. Nearly there, I promise.
Just wanted to get the wiring layout absolutely straight before I go ahead and connect it up, and then call a spark to check my work.
I plan to take a live and neutral from an existing junction box on the lighting circuit then to a double pole isolator, take the live and neutral from the isolator to a fused control unit then on to the fan, take the switched live from the "live out" terminal on the DP isolator to the switch and connect it to the terminal marked Common, then take it from either L1 or L2 on the switch to the T terminal on the fan. Anything wrong there?
Using an isolator AND an FCU sounds like duplication, but the instruction diagram with the fan specifies that I need a fuse, and I don't seem to have been able to persuade the electrical factors store to sell me a fused double pole isolator. Does such a thing exist? If not, would a FCU do the job on its own?
The cable will be routed within self adhesive mini-trunking from the ceiling down the wall to the fan itself; a distance of about 18 inches. I've read somewhere that there has to be at least 45 per cent of the space within the trunking free once the wiring is installed, and I think this is to guard against overheating. Would this rule apply for an appliance that pumps out just 12watts?
Our local electrical factors, when I told them that I needed to supply a fan from the lighting circuit, sold me a 3 core cable with black, brown, grey and a bare CPC; the exterior diameter is 10mm diameter and core diameter is listed on the receipt as 1mm. Is this the correct cable for the job or has something been lost in translation?
Edit: I know we talked about twin and earth earlier in this topic, but the above cable seems to be the same as the stuff supplying the lighting circuit, rather than what as a layman I understand to be "twin and earth."
Thanks again.
Just wanted to get the wiring layout absolutely straight before I go ahead and connect it up, and then call a spark to check my work.
I plan to take a live and neutral from an existing junction box on the lighting circuit then to a double pole isolator, take the live and neutral from the isolator to a fused control unit then on to the fan, take the switched live from the "live out" terminal on the DP isolator to the switch and connect it to the terminal marked Common, then take it from either L1 or L2 on the switch to the T terminal on the fan. Anything wrong there?
Using an isolator AND an FCU sounds like duplication, but the instruction diagram with the fan specifies that I need a fuse, and I don't seem to have been able to persuade the electrical factors store to sell me a fused double pole isolator. Does such a thing exist? If not, would a FCU do the job on its own?
The cable will be routed within self adhesive mini-trunking from the ceiling down the wall to the fan itself; a distance of about 18 inches. I've read somewhere that there has to be at least 45 per cent of the space within the trunking free once the wiring is installed, and I think this is to guard against overheating. Would this rule apply for an appliance that pumps out just 12watts?
Our local electrical factors, when I told them that I needed to supply a fan from the lighting circuit, sold me a 3 core cable with black, brown, grey and a bare CPC; the exterior diameter is 10mm diameter and core diameter is listed on the receipt as 1mm. Is this the correct cable for the job or has something been lost in translation?
Edit: I know we talked about twin and earth earlier in this topic, but the above cable seems to be the same as the stuff supplying the lighting circuit, rather than what as a layman I understand to be "twin and earth."
Thanks again.
I think all fused isolators are double pole. So you don't need 2 switches.
Yes they sold you the correct cable, although with your layout you will probably have a spare wire.
Yes they sold you the correct cable, although with your layout you will probably have a spare wire.
On balance it would have been so much quicker, easier, and probably little more expensive for you to have just had an electrician do the whole job.
What sort of "checking" are you expecting the electrician to do, and how much are you expecting to pay?
Is any of the electrical work within Zone 1 or 2?
Thank you.
Anyone want to buy a double pole isolator? Brand new out of the box and never used.
Onwards and upwards...into the loft.
One other, non-electrical question but it is kind of connected to this topic. The exterior shutter of the fan opens every time someone closes the bathroom door, and usually stays open, which creates a draught. I've tried WD40, which I know is primarily a water repellent rather than a lubricator, but it makes no difference. I even stuck a tap washer onto the top shutter with silicone but the bleeping thing still opened up, and all this before the fan is even connected. Anyone know of any tricks that might make this thing stay shut until its required to open? I know its not warped because I was careful to install it nice and flat against the wall and if you flick the shutters open from the outside with your fingernail they drop down immediately.
I don't give a monkey's about a bit of a draught, but other members of the household are now complaining of goosebumps (yes, the same ones who complained about condensation).
Anyone want to buy a double pole isolator? Brand new out of the box and never used.
Onwards and upwards...into the loft.
One other, non-electrical question but it is kind of connected to this topic. The exterior shutter of the fan opens every time someone closes the bathroom door, and usually stays open, which creates a draught. I've tried WD40, which I know is primarily a water repellent rather than a lubricator, but it makes no difference. I even stuck a tap washer onto the top shutter with silicone but the bleeping thing still opened up, and all this before the fan is even connected. Anyone know of any tricks that might make this thing stay shut until its required to open? I know its not warped because I was careful to install it nice and flat against the wall and if you flick the shutters open from the outside with your fingernail they drop down immediately.
I don't give a monkey's about a bit of a draught, but other members of the household are now complaining of goosebumps (yes, the same ones who complained about condensation).
BAS, I did try to get an electrician here to do the job but my enquiries met with no response.
Hopefully one of our local sparks will consider it worth his while just to pop into the loft and check the wiring, but you're right; my first intent was to get a man with the relevant qualifications to do the job rather than do it myself, and I would have happily paid for it had someone responded.
I'll pay the going rate for having the safety of the work checked, whatever that happens to be, and put it down to experience.
Edit: I've just looked again at the zone classifications and the fan is about three feet above the toilet cistern, diagonally about four feet above and away from the sink, and around six feet away from bath and shower, which I think is classed as outside zones.
Hopefully one of our local sparks will consider it worth his while just to pop into the loft and check the wiring, but you're right; my first intent was to get a man with the relevant qualifications to do the job rather than do it myself, and I would have happily paid for it had someone responded.
I'll pay the going rate for having the safety of the work checked, whatever that happens to be, and put it down to experience.
Edit: I've just looked again at the zone classifications and the fan is about three feet above the toilet cistern, diagonally about four feet above and away from the sink, and around six feet away from bath and shower, which I think is classed as outside zones.
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
Sponsored Links
