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SELV - Not a fan of?

whjohnson
Short question - is a mains voltage extractor fan permissible in zone 1 or 2 in a bathroom provided it is protected by a 30ma rcd and that all IP requirements are met??

OSG chapter 8, Table 8.1, page 94 says only 25vAC or 60v ripple-free DC SELV or PELV, yet I have just been to the wholesalers to look at what they have, and they showed me two mains fans with "Suitable for" or "Complies with" Zone 1 emblazoned on the packaging.


I am looking to fit a fan with a humidistat but am struggling to find a SELV version if that is actually required.

So, which is correct? The manufacturer (whose instructions must be followed) or the on site guide, whose instructions must also be followed!


Comments welcome.


  • 0
    whjohnson:

    A quite bizarre experience - I had the wholesaler - ex electrician - telling me that a 230v fan was acceptable in zone 1, then I had the OSG giving me mixed messages about DC ripple & SELV only  It all seemed to be couched in a non-committal kind of style with plenty of only ifs, but 's & maybes to the point whereby it may as well have been an eu directive drafted by a pub lawyer.

    Why can't the requirements be more prescriptive whereby they leave the reader in no doubt as to what is actually required and what will actually comply?


    I could carry out the installation in 2 ways, mains, then SELV and invite as many seasoned 'inspectors to check each  one, and you can bet that neither installation method will satisfy all of the inspectors at the same time, such of the inconsistency of the message. Meanwhile I am attempting to do my bets by following the wiring regulations and the manufacturer's instructions (as demanded by the wiring regulations) and am sensing conflict between the two - no, not full conflict, but slight friction. So I fit a 230v fan in zone 1 and someone is fatally electrocuted, despite the manufacturer's zone 1 compatability claims. Their prosecution rep will be all over the wording of the OSG like a tramp on a tray of silt chips. I can see it now - "Best of your knowledge and ability sir? But you didin't follow the wiring regulations, specifically...........and I have an expert witness here to prove it"

    .


     


    I'm not sure I agree with you about the OSG, but as others have said, it's BS 7671 that really matters, and that is quite clear. There are indeed different requirements for switchgear and controlgear to fixed current-using equipment (to socket-outlets) in the zones ... as there have been for a long time.


    The OSG does not conflict - but if you can let the Forum know what's unclear for you in the OSG, perhaps we can help with that.



    I've picked up a 20-year old 16th Edition, and a the 2008 and 2011 17th Editions, and not a great deal has changed with respect to either switchgear/controlgear or current-using equipment in Zone 1, save that the 17th and 18th Edition requirements seem a lot clearer with regard to the sorts of mains-powered current using equipment that's likely to be suitable in Zone 1


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