If you Install an exhaust fan with timer, & use the 5A Lighting supply Circuit, do you have to install a 3 Pole isolating Switch?

Under Irish regs, you do thesedays.

Have to be able to isolate the permanent live, the switched live and the neutral for maintenence.

If you've fans with humidistats the fan isolation switch can be very useful. We have them and on very humid days the fans can start to run constantly!

[This message has been edited by djk (edited 10-17-2005).]

Thanks DJK

Here in NZ you would not require a 3-pole isolator.
Depending upon your type of fan, the phase coming in would be fed to the light switch and then on to the fan isolator, as in continuously live.
The fan isolator would have a switch that looks like this:



The fan supply needs to stay energised so that the timer works.
There is no need to break the Neutral.

The 3-pole isolator has become the norm here for timed fans:



MK is now making a version with a lock out provision, although from the pictures I can't quite figure out how the padlock is supposed to work:



I'm trying to think when these isolators first appeared. I think it might have been with the 15th edition (1981).

Thanks for that Lads!
Is the Isolator allowed by law to be mounted in the bathroom, or does it need to be mounted outside the bathroom?
Can it be mounted in the loft above the bathroom? (Trumpy..do you play for the All Blacks? if you do I'll see you in Cardiff on Bonfire-night!!!)

Well, by law you can put it almost anywhere you like in a private house, since there is nothing legally enforcable about BS7671.

However, as far as the Regs. are concerned it can go inside the bathroom, subject to being located outside the appropriate zones as for any other switch.

I wouldn't locate the isolator in the roof space unless the fan itself is mounted there (i.e. an "in line" unit with ducting to the grill over the tub/shower).


[This message has been edited by pauluk (edited 10-19-2005).]

Thanks Paul, very helpful. (AS usual)!

U/Dog,
Hehe,
At one time I probably could have, however these days, it's called Middle Age Spread and we all know what that means.
I wouldn't even get in as an Assistant Deputy Understudy to the Orange Boy.

You could probably get a game easy for the Lions then!!!!

PaulUK: The padlock and red brackets are used for locking-off the isolator. There are holes on the side edges of the rocker. The red brackets grip into these holes and prevent the rocker being depressed into the ON position. The two halves of the bracket are padlocked together so the bracket cannot be removed without the key.

Uppeydog: The isolator can be mounted anywhere, but if it is not under the control of anyone working on the fan it must be lockable-off so the fan cannot be energised inadvertently by someone else.

Owain Glyndwr (where have you been for the last 600 years?),
thanks for that. My mate wants to put this fan right above the shower, is there any distance specs. for that, he's got 4 kids, i.e. 4 showers, stacks of steam & condensation.

Thanks, William Wallace!

Hi Owain, welcome to ECN.


Ah.... Thanks. I've not come across one of these types yet, and I wasn't thinking about the bracket being in two sections. It's obvious looking at it now that it has to be two parts, otherwise you wouldn't be able to fit it onto the rocker.

Some days the old gray matter isn't firing on all cylinders......



[This message has been edited by pauluk (edited 10-28-2005).]

The position of the fan (and isolator) is subject to the same Zone requirements of all bathroom electrical appliances. These are summarised at
http://www.diydata.com/electrics/bathroom_electrics/bathroom_electrics.htm

If the Zones / IP rating cannot be complied with, low-voltage fans (some incorporating a light) are available, or in-line fans can be used in ductwork outside the bathroom.

Uppeydog,
if you are positioning a fan within a bathroom (shower room) please ensure that the Building Regulations are adheared to.

these supercede the wiring regulations within a domestic dwelling.

we, ( when we do domestics, and that aint often ) position the fans in accordance with the building regs, over a shower we use a SELV ( 12v) fan the power supply/timer unit is usually mounted externally of the room on the wall coupled with a triple pole switch disconnector, from the general lighting supply.

we do not, ever position a switch inside the shower room / bathroom area, unless it is a pullcord for the general light.

be carefull on this one as it comes under the infamous PART P regulations and is `notifiable` addition to the installation , unless you are just changing the fitting,.

PaulUK have you an abridged version of PART P?

Britspark

( we try not to have anything to do with domestic dwelling works as they are a pain in the axx ).

The only legally enforcable requirements under the Building Regs. are already so short that there's not much to abridge:


That's it!

The actual Statutory Instrument which added Part P is the usual wordy bureaucratic prose, but it does have the list of works which are exempt. Scroll down to Schedule 2B:
http://www.opsi.gov.uk/si/si2004/20043210.htm


The "Approved Document" for Part P can be downloaded from here:
http://www.odpm.gov.uk/index.asp?id=1130906

There is nothing in this document which is actually the law in itself, but it does include a summary of the works exempt from notification on page 11.


[This message has been edited by pauluk (edited 11-13-2005).]

Paul Owain Britspark,

Thanks for the professional replies.
Although an original installation, have placed it in a zone 3. On/off light/fan switch outside door. Triple pole isolating switch mounted inside loft door.

Uppey.