Extractor fans - is the double pole isolator switch mandatory?

Can someone tell me whether it's recommended or mandatory to install a double pole isolator switch on a bathroom extractor fan? If mandatory I presume anywhere other than z1 or z2 is OK?

Reply to
Dave
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Certainly mandatory if it has any form of overrun (timer, humidistat etc) but AFAIK there's some disagreement as to whether it's needed if the fan is controlled only from a normal switch, on it's own (ie with no source of power from anywhere else). I fitted one like this during a recent rewire and asked the sparks who was going to be testing my wiring, and he said the DP isolator wasn't needed then.

Others will be along shortly to disagree with this!

David

Reply to
Lobster

I'd say, "a good enough idea that you should do it".

Pinhead-dancing angels would go into the subtelties of isolation vs functional switching vs switching-for-maintenance and so on.

Reply to
Stefek Zaba

It is recommended but not mandatory, most rented accommodation I visit don't have and they have passed an electrical inspection.

If you do put one in why not leave it in the loft if you have access.

Dave Jones

Reply to
Dave Jones

I wish I had read this prior to cutting out a space for a recessed box to fit an isolation switch to

Reply to
John Borman

Instead, you should be glad that you had not read the very bad advice just given and have done the job properly.

Above all a fan isolator (3-pole, BTW, if the fan takes a switched live control feed from the bathroom light) is required to comply with Reg.

131-14-02: "Every fixed electric motor shall be provided with an efficient means of switching off, readily accessible, easily operated and so placed as to prevent danger."

Putting the switch in the loft is not an acceptable option, any more than than is hiding appliance control switches in kitchen cupboards. These things are meant to be accessible.

Reply to
Andy Wade

On Wed, 29 Dec 2004 16:21:13 GMT, Lobster strung together this:

You mean battery powered? If you have no external source of power then it needs an isolator. If the fan requires an isolator when it is a timer model that's because it is a fixed appliance. If it is a non-timer model it's still a fan, so needs an isolator.

When is a fan not a fan? Never.

He wants sacking.

Yep, I'm sure they will. ;-)

Reply to
Lurch

On Wed, 29 Dec 2004 19:25:02 -0000, "John Borman" strung together this:

It's mandatory, if you're going to do it do it properly.

No they haven't, they've been tested by someone who doesn't know what they're doing.

Well, that would be wrong. Don't believe everything you read on usenet. If the fan is in the bathroom then it is no good putting the isolator in the loft. It should be reasonaly local to the appliance it's controlling unless it's lockable in the off position.

Reply to
Lurch

It may acceptable, and indeed appropriate. To reduce noise, many such fans are loft mounted rather than being part of their inlet plate. So long as the switch is accessible from the sensible access route to the motor, then there's no problem with loft mounting it.

Reply to
Andy Dingley

110-04-01 The Regulations are non-statutory. .....

i.e. NOT mandatory

They have passed an electrical inspection, wether the person was competent or not is another thing.

I did say if you have access, a loft with a loft ladder or other means, would be more suitable than a switch located on a 9 ft ceiling, where by you have to use a ladder/chair in order to use it.

"Every fixed electric motor shall be provided with an efficient means of switching off, readily accessible, easily operated and so placed as to prevent danger."

So with that in mind an isolating switch could be placed any where within a reasonable distance of the fan, either inside or outside the bathroom, providing you have access.

Reply to
Dave Jones

Try one of these:-

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So with that in mind an isolating switch could be placed any where within a

You can go for a switch outside the bathroom if you prefer.

Reply to
John Rumm

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

David

Reply to
Lobster

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

No, a fan is a fan.

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.

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.

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?

Reply to
Lurch

On Thu, 30 Dec 2004 09:31:40 -0000, "Dave Jones" strung together this:

That's why pull switches were invented, or put it lower down the wall.

Reply to
Lurch

OK & agreed. I was talking about the case where the fan motor is in the bathroom.

Reply to
Andy Wade

I agree been thro this before with built in kitchen appliances needing a isolator how simple can it be ?

Peter

Reply to
Peter

One question though - how come a lightbulb isn't a fixed appliance ?

Reply to
Mike

Because it is simple to un-plug it from its holder. A fixed appliance is one which is connected directly to a supply source with connections that need a tool to be able to remove it. In this case, your hand is not classed as a tool.

Reply to
BigWallop

It is - or rather a luminaire is fixed equipment. Isolation requirements for the circuit are met at the consumer unit by way of an MCB and/or main switch with provision for locking-off. The additional specific requirements for a fan arise because of the presence of a motor. [See pp. 34-35 in the OSG.]

BTW isolators don't, in general, have to be double-pole, except in TT-earthed installations, and except for the main switch(es) of a single-phase domestic installation. (In 3-phase installations it's very common practice for isolators to be 3-pole with a solid removable neutral link.)

Reply to
Andy Wade

Whereupon it's easy to touch neutral for an ES holder. So why aren't light switches double pole ?

Reply to
Mike

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