On Thu, 30 Dec 2004 11:54:08 GMT, Lobster
strung together this:

No, mains; I was making the distinction between a fan which receives its
power via a single source, ie, through a wall switch or pull-cord
switch, and one which has a second live feed as in the case of a fan
wired to come on and off with the bathroom light, but with provision for
overrun after the light has been switched off.

But you must admit there's a fundamental difference in the two different
types of fan described above, surely?

No, a fan is a fan.

The whole point of having an
isolator on a fan is so it can be properly switched off for maintainence
while the light is switched on, yes?

No, the point in having the isolator is so that it can be isolated for
maintenance, irrespective of the lighting in the room or the
appliances method of connection.

Common sense says that's not
necessary if the fan is already wired through its own, dedicated switch.

You're getting two terms mixed up here.
An isolator isolates all live cables for maintenance purposes, i.e.
live and neutral supplies switched or not.
A switch switches in the live wire to the appliance, therefore it
isn't an isolator, it is a functional switch to turn the appliance on
and off.

If you're going to insist that such a fan needs an isolator too, then
why not insist that each and every light fitting has one, too?

I'm not insisting, BS7671 is insisting. As we're all meant to be
working to that standard what are you getting at me for?
A fan is a fixed appliance, a fixed appliance needs an isolator. How
clearer do you want it?
--

SJW
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