Bathroom fans. Do they need to be fused or just iscolated?

Discussion in 'Electricians' Talk' started by Djdemon, Jun 4, 2016.

  1. Djdemon

    Djdemon New Member

    Hi there. I have a timer bathroom extractor to fit. It will come on with bathroom lights and have permanent live to run after light is turned off. I fully understand the wiring requirements for this. However, the fan instructions state that I should have a fused spur with a 3a fuse protecting the fan. Now the fan iscolator isn't fused and my fused spurs are only normal 2 pole so I would need 2 of them to protect both the switch live and the permanent live.
    This all seems completely unnecessary. I am aware that I could just put the fused spur before the light junction box and run the lights and fan through it but that doesn't seem normal either. Do I really need to have a 3a fuse spur as well as the iscolator switch? What's the deal on wiring it all in?
     
  2. CGN

    CGN Screwfix Select

    Just an isolator required in most circumstances.
     
  3. leesparkykent

    leesparkykent Well-Known Member

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  4. seneca

    seneca Screwfix Select

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  5. seneca

    seneca Screwfix Select

    If makers instructions recommend a 3 amp fuse then one should be fitted. A common way of doing it is to feed the bathroom light and the fan from the fcu with the 3amp fuse in it.
    I have been fitting Greenwood fans for some time now because they don't stipulate a 3a fuse if they're on a 6amp mcb.
     
    leesparkykent likes this.
  6. leesparkykent

    leesparkykent Well-Known Member

    I think you can also make them up using the click mode stuff :)
     
  7. peter palmer

    peter palmer Super Member

    This is about being a conformist again, do you always do what you are told? I have fitted fans for years off the local lighting circuit via a 6A MCB and never had a problem and I doubt I will have any time soon. I have also seen a few jammed fans and never have I seen one that looks like it will burn the house down.

    Wouldn't surprise me if we see metal fans compulsory in the new regs, they have to keep themselves in jobs somehow dreaming up new "safety" features.
     
  8. leesparkykent

    leesparkykent Well-Known Member

    IMO it's prudent to follow manufacturers instructions where possible. If this makes me a conformist then so be it. I don't find in necessary to constantly go against the grain.
     
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  9. peter palmer

    peter palmer Super Member

    Neither do I but you have to know when some rules are stupid otherwise you become a drone.
     
  10. nffc

    nffc Active Member

    Manufacturers instructions now only need to be considered. Not blindly followed.
     
    leesparkykent likes this.
  11. Djdemon

    Djdemon New Member

    I never knew you could get a fused, 3 pole iscolator. Cheers Lee! That's my answer.

    It's the screwfix manrose in-line fan kit that specified I should have a fuse. Yep of course I have considered not fusing it and I have considered fusing the lights and fan all in one - but that fused iscolator will do nicely and it's the same kind of price as a non fused one! Thanks guys.
     
    leesparkykent likes this.
  12. Djdemon

    Djdemon New Member

    Thanks Lee. Shame screwfix don't stock these themselves. It's what I was searching for! I'd have thought they'd be quite a commonly bought thing. I'd be interested to know if (or how) that one fuse in the switch protects both of the live poles though!
     
  13. leesparkykent

    leesparkykent Well-Known Member

    It doesn't so you would have to wire it so it fuses the lights also or use a double pole switch for the light switch and alter the wiring slightly. This way the permanent live and switch live would be fused by the 3A if you require this.
     
  14. leesparkykent

    leesparkykent Well-Known Member

    I wouldn't ever blindly follow manufacturers instructions as I've come across some that if I did then it would be considered dangerous. Something simple like this though I don't see it being to much of an issue just to Install a fused fan isolator which isn't going to add a significant amount of money to the job. And if the proverbial did ever hit the fan for what ever reason then I would be covered as I've followed the manufactures instructions.
     
    nffc likes this.
  15. philthespark

    philthespark Active Member

    Following instructions can seem silly at times but sometimes not following them can bite you in the bum! I was once hauled over the coals for booking out a gallon of engine oil for my new company van. In the manual it stated something like "use only Total 5w40 in this engine,so I went to the garage and booked a gallon on the firm's account.The boss went mental,"we've 45 gallons of 5w40 in the workshop,yet you decide to get your own tub at nearly 20 quid a gallon!"
    I argued my point but still got a right bollocking,3 weeks later one of the vans blew an engine,the warranty was void as the wrong oil had been used.Apparently the one specified was fully synthetic,the one we had in the workshop was mineral based.That same boss who'd reprimanded me for wasting money on oil we already "had", then tried to make the other driver foot the bill for the new engine,despite it being him who'd told the driver to use the "correct oil" that we had in our workshop!
     
  16. Djdemon

    Djdemon New Member

    It does pose the question..... Why have they not made a twin fuse fan iscolator?! Mk or someone need to get on it
     
  17. JP.

    JP. Screwfix Select

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  18. Risteard

    Risteard Screwfix Select

    A better solution than having two fuses is to run the bathroom light from the 3A fuse, which gives you both permanent and switched line (phase) conductors for your fan (and fused down).
     
    seneca likes this.
  19. seneca

    seneca Screwfix Select

    That's the way to do it.
     
    Risteard likes this.

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