No, we normally assume that a 3A fuse is required to save the fan or its wiring should the motor jam - overload - because it is (poorly made and) not fitted with an integral fuse.
Well, I think we assume that it is 'required' to protect the fan or its wiring should 'something' (less than a 'dead short') happen within the unit to increase current drawn. A jammed motor is undoubtedly the most likely cause of that. Having said that, I've had a good few 4" extractors 'jam up' over the years - and no OPD has ever operated, and nor has there been any smoke or flames - IIRC, they just 'get a bit warm'!
If it's a full-blown 'negligible impedance' fault, then yes, but 'they' may be thinking of a lesser degree of S/L-N 'fault' than that. It's obviously all silly - in sensible terms, the S/L does not need fusing (and, come to that, nor probably does the permanent L!).
Then you'll get warm moist air entering the loft where it will cause condensation.
It doesn't need to be fire retardant, and if it's an intumescent substance it won't swell up and seal anything unless there's a fire.
Actually I said they are often known as spotlights. Which they are.
As you observe, if these lights were designed to provide general room illumination then the OP would not need 8 of them.
Would that circle be uniformly lit?
You did - but it was indicative of your ongoing way of thinking.
I don't think any sensible person would describe a light with a beam angle of 120° as a 'spotlight' (at any significant distance, it would be a mighty big 'spot'!).
I don't believe that he does need 8.
I don't know. Obviously not 'perfectly uniform', with "100% illumination" at 8.300000m and "zero illumination" at 8.300001m, but I suspect it's not appreciably less uniform than any other light source with a 120° beam angle.
Well of course it is. However I can't see that there would be any more moist air flow through/past these fittings than there would through a traditional bathroom light (and its wiring hole).
It is a small bathroom, and a low loft, so there are three cold water tanks and the hot water expansion tank all above the bathroom. Strictly they are only half the width of the bathroom, but that width includes all the places lighting would sensibly go.
Indeed - which is why that is not a very common way of doing it. There is an alternative approach which uses a double pole light switch - one pole then switches the ('fused') live to provide the S/L for the fan, whereas the other pole just switches the usual 'unfused' live for the light. You may be getting confused by talking about the "downfuse/isolator" - if one wants 3-pole isolation, they will inevitably be two different things.
See above. To be useful/safe, the (3-pole) isolator obviously has to isolate all conductors going to the fan, regardless of which are and are not fused.
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
