I am planning to install a bathroom extractor fan directly onto the external wall. Can I provide permanent power from outside the bathroom and have the on/off switch outside the bathroom. (ie run all wiring thro the wall from the adjoining bedroom, and not from the bathroom celing light).
you'd be better off posting this topic on the electrical forum.
i assume from your query that you are thinking of spurring from a nearby socket?
extractor fans are designed to run from the lighting circuit. they are activated/deactivated when the light is switched on and off. some have timers so they over-run when after light is switched off - these require a permanent feed.
in theory it's possible to run a spur from a socket but it would need to be fused down via an FCU and the correct cable rating used. no switch would be permissible in the bathroom itself and all other aspects of the part p regulations, including wiring regs, must be adhered to.
i actually doubt that it would be any more straightforward to run a feed and fit a switch to a socket spur than from the lighting circuit - in fact quite the opposite.
part p regulation is quite hefty when it comes to bathrooms so if you are not sure i'd strongly advise that you get in a professional to take a look.
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