Fusing down of extractor fans

uksparks · May 8, 2015

Hi,

I have a question I would like to put to you to see who does what really.

The majority if not all manufacturers state something about the fan must be fused down to 3A...

Ok, scenario...

You have a bathroom, 6A light circuit, the light can either be switched at pull cord, light switch outside or the light fitting.

The customer says they want an extractor fan with Timer.

Option One
Do you just fit a fan in the ceiling / wall, and connect it off the light circuit straight to it and think nothing of it? This would be a permanent live supply and switched live.

Option Two
Do you fit a fan, and put a 3A fuse on the permanent live only? Leaving the switched live on 6A, also leaving the fan with the possibility of a blown fuse scenario but also having a live supply to it. You also fit a 3 pole fan isolator.

Option Three
Do you fit a fan, and put a 3A fuse on the permanent live supply to the light, then use that for the live for the fan, and the switched side of the light for the switched live etc. You also fit a 3 pole fan isolator.

Just to add to this
On top of these three options, lets say this is downstairs, no loft space etc, brick walls. You need to put a 3 pole isolator somewhere, where do you put it? Do you surface mount it in a box? Do you use a 3 pole pull switch on the ceiling? But hang on, where do you then put the 3A fuse? Do you not bother? Do you put in on the surface or ceiling?

Just wondering what others do as have been having this conversation with a couple of people. I also rang Manrose about this about putting a 3A fuse across the switched live too, they said, although preferable, it only really needs it on the permanent live.

Corbs · May 8, 2015

option 3 and fit on the surface mounted 2g (2x1g) pattress by the door/ on the outside of the door

or if you want to be overcomplicated don't use the light as a sl because sometime in summer people don't use lights/ need lights, fit a separate pull cord just for the fan so they can switch the fan on separate to the light. (If for use in a shower room)

Leesparkykent · May 8, 2015

Corbs said:
option 3 and fit on the surface mounted 2g (2x1g) pattress by the door/ on the outside of the door
or if you want to be overcomplicated don't use the light as a sl because sometime in summer people don't use lights/ need lights, fit a separate pull cord just for the fan so they can switch the fan on separate to the light. (If for use in a shower room)

Excel 3 Pole Fused Fan Isolator Switch - White | QVS Electrical Wholesalers

Corbs have you seen these? Not as obtrusive as having 2x1gang pattress or a dual pattress.

Leesparkykent · May 8, 2015

Personally I would use a fan that doesn't state it needs fusing down to 3amp such as a greenwood fan.

uksparks · May 8, 2015

Leesparkykent said:
Excel 3 Pole Fused Fan Isolator Switch - White | QVS Electrical Wholesalers

Corbs have you seen these? Not as obtrusive as having 2x1gang pattress or a dual pattress.

I think these are the same as the ones I have just been looking at in BED Electrical.

Leesparkykent said:
Personally I would use a fan that doesn't state it needs fusing down to 3amp such as a greenwood fan.

I wish you luck finding one!

Leesparkykent · May 8, 2015

uksparks said:
I think these are the same as the ones I have just been looking at in BED Electrical.

I wish you luck finding one!

Vortice and silavent are a few.

Octopus · May 8, 2015

uksparks said:
I think these are the same as the ones I have just been looking at in BED Electrical.

I wish you luck finding one!

greenwood

NDG Elecs · May 8, 2015

I don't see much wrong with reliance on the 5/6 amp OCPD. Have never seen a fan go up in flames nor heard of one doing so. One good thing with AMD3 is the slight change regarding how we have to view and take into account MIs.

I stand to be corrected on this. So tin hat at the ready!

DPG · May 8, 2015

Agree with someone else's post above - why have the fan coming on with the light at all?? Half the time we have a shower it's still daylight so the lights don't get switched on. We just use the pull cord on the fan. Daz

telectrix · May 8, 2015

i generally wire fan independent of the light. apart from the advantage in DPG's post, it also means you don't have to have a noisy fan waking everone up at 2 a.m. when you go to recycle your ale intake.

Deleted member 72666 · May 8, 2015

telectrix said:
i generally wire fan independent of the light. apart from the advantage in DPG's post, it also means you don't have to have a noisy fan waking everone up at 2 a.m. when you go to recycle your ale intake.

But on the other hand it'll drown out the sound of the release of excess gases and remove the stench to boot lol!

telectrix · May 8, 2015

stantheman said:
But on the other hand it'll drown out the sound of the release of excess gases and remove the stench to boot lol!

who cares?

HappyHippyDad · May 8, 2015

TheGayOwl said:
I don't see much wrong with reliance on the 5/6 amp OCPD. Have never seen a fan go up in flames nor heard of one doing so. One good thing with AMD3 is the slight change regarding how we have to view and take into account MIs.

I stand to be corrected on this. So tin hat at the ready!

Could you expand on that a little GayOwl?

I think you're referring to 134.1.1?

If you are then I can see the difference in the wording of the reg compared to the BGB, however..

"The Installation of electrical equipment shall take account of the manufacturers instructions"

Does that still mean we HAVE to follow MI's as in the previous 134.1.1 or does it mean we can now give it 'consideration', and if we deem the install to meet all other regs and to be safe we do not have to follow MI's?

ruston · May 8, 2015

I've started to fit Xpelair infra red fans, bit pricey but ideal for problem bathrooms.

Richard Burns · May 8, 2015

happyhippydad said:
Could you expand on that a little GayOwl?

I think you're referring to 134.1.1?

If you are then I can see the difference in the wording of the reg compared to the BGB, however..

"The Installation of electrical equipment shall take account of the manufacturers instructions"

Does that still mean we HAVE to follow MI's as in the previous 134.1.1 or does it mean we can now give it 'consideration', and if we deem the install to meet all other regs and to be safe we do not have to follow MI's?

The previous regulation stated must be installed in accordance with the manufacturers instructions, however this is patently ridiculous for minor items such as light fittings where the manufacturer does not write comprehensive installation conditions (and often get it wrong), it may be much more sensible for complex items of integrated equipment, however the manufacturer cannot cover all eventualities so some level of autonomy should be given to the installer.
As 510.3 states take account of manufacturers instructions they are simply aligning the two differing regulations so that there is concordance between them.
Taking account of the instructions means that you must make a conscious decision not to follow them for well founded reasons, such as regulatory compliance! But you must know what they are and why you are not following them.

As they say, if all else fails, read the instructions!:smile5:

Fusing down of extractor fans

uksparks

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Leesparkykent

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