I'm afraid it's 134.1.1. As you may have noticed, this is one of my pet hates as it is totally unnecessary and the equivalent of the manufacturers stating that we must install their fans using only 2.5mm² T+E.
Hmmm. Although I have to agree that the words are clear enough, I often wonder if 134.1.1 doesn't perhaps get taken too literally. There are clearly some situations in which the MIs could be important, but I doubt that those who wrote 134.1.1 were really thinking about 'silly' requirements of MIs, relating to things which would not be required in the absence of the MIs. I think that definitely applies in the case of fan isolation. The manufacturer is not going to know any more than the IET do about the need for an isolator - so why should they be able to impose a requirement for something that the regs would not otherwise require? Having said that, I suppose that an electrician probably has little choice but to obey MIs (hence 134.1.1), even when silly.
Maybe electricians should act collectively in an attempt to apply 'market forces'. If it were to be made known that electricians were going to, wherever they could, cease buying and fitting things which had 'silly' requirements in their MIs, then maybe at least some manufacturers would edit their MIs
the main reason for having an isolator near to a fan is to prevent an electrician having to work on it in the dark - but the regs don't have that one.
Is anyone sure that this is not just an urban myth?
Who knows - I'm merely repeating (thereby maybe perpetuating a myth) what several others have said to me - here and elsewhere.
A more plausible reason would be because their fans are rubbish and prone to sticking and causing an electrical/thermal problem which an isolation switch would negate so that the lights can be used until the fan is replaced.
That's another possibility, although even bad fans usually last a year or three. In any event, I suppose you would merely have to substitue 'householder' for 'electrician' in the 'myth' (for the person being inconvenienced) - since the other option is to switch off the entire circuit until repaired.
After all why is it not required that all rooms without windows be supplied with two lights on separate circuits so that we don't have to work on them in the dark?
However, as I think we are agreed, even with fans, except for the MI, there's no requirement in the regs for any 'electrician convenience' measure!
Kind Regards, John.
