Bathroom extractor fan without fuse

[Leesparkykent]

Sounds a right performance.

no not really if your chucking the cables in on a 1st fix.

 

[Deleted member 9648]

This came about because some years back a fan caused a fire, and because the contractor had not installed a 3a fuse as per manufacturers instruction he was prosecuted for causing the fire. Nobody stated the bleeding obvious that a 3a fuse would not have made a scrap of difference. This led the NICEIC to advise their contractors to fit the fuse...and to code non fused fans. Bull**** but there you go.

 

[haptism]

Ive been out the loop for10ish years and slowly getting back into it all again because it gives me something to focus on; the non fused fan isolators were familiar, never seen these fused ones until now;

 

[westward10]

I don't get these fused triple-pole switches, they only fuse one of the poles so what is the point. May as well use a standard triple-pole switch with a two gang grid with two fuses fitted. Am I misreading this.

 

[Wilko]

Ive been out the loop for10ish years and slowly getting back into it all again because it gives me something to focus on; the non fused fan isolators were familiar, never seen these fused ones until now;

Hi H, you are not alone. Lee's 3 pole fused isolator is one of the many neat things I have learnt here. Cheers

 

[Wilko]

I don't get these fused triple-pole switches, they only fuse one of the poles so what is the point. May as well use a standard triple-pole switch with a two gang grid with two fuses fitted. Am I misreading this.

With Tin Hat On, I'm hoping I've got it : the unit has a separate fuse to the 3 pole switch so we can fuse the incoming L and then split it into L for the fan (via 3pole) and send L off to the other half of the new DP light sw, when it comes back it goes into as SL (via the 3pole). Clear as mud ?

 

[Leesparkykent]

I don't get these fused triple-pole switches, they only fuse one of the poles so what is the point. May as well use a standard triple-pole switch with a two gang grid with two fuses fitted. Am I misreading this.

could do but will look rubbish.

 

[Leesparkykent]

With Tin Hat On, I'm hoping I've got it : the unit has a separate fuse to the 3 pole switch so we can fuse the incoming L and then split it into L for the fan (via 3pole) and send L off to the other half of the new DP light sw, when it comes back it goes into as SL (via the 3pole). Clear as mud ?

Spot on

 

[westward10]

Am I correct that it does in fact fuse only one pole, sorry if I am being dumb but I really don't get it.

 

[haptism]

All cartridge fuse only one pole for overload, just like an inline fuse ?!

edit missed the last posts, but still I would guess it only fused the one pole for overload

 

[Wilko]

All cartridge fuse only one pole for overload, just like an inline fuse ?!

edit missed the last posts, but still I would guess it only fused the one pole for overload

Both L and SL for fan can be fused, but it needs another pole on the light sw and cabling.

 

[westward10]

Both L and SL for fan can be fused, but it needs another pole on the light sw and cabling.

Does the switch come with instructions for this because it would be easy to get it wrong.

 

[Leesparkykent]

Does the switch come with instructions for this because it would be easy to get it wrong.

No because there is a few ways to achieve the same outcome.

 

[Richard Burns]

Presumably the option is there to wire it as you require however I would expect that most people might wire it like this:

As this covers the most obvious arrangement that is identified on most fan installation instructions (assuming the TP isolator has a 3mm contact gap)

 

[westward10]

No because there is a few ways to achieve the same outcome.

Must admit I have never seen these switches. They seem to be a solution for a problem which isn't really there and only solves the so called problem by 50% leaving the installer to put in place the rest of the solution. This really should be made clear by the manufacturer.

 

[mydigitalhome]

I normally wire FSO with 3A fuse and bring the complete bathroom lights down to 3A then next to that 3pole fan isolator for fan over run and all legal easy on new build less fun on existing but not impossible.

 

[HandySparks]

Must admit I have never seen these switches. They seem to be a solution for a problem which isn't really there and only solves the so called problem by 50% leaving the installer to put in place the rest of the solution. This really should be made clear by the manufacturer.

Why do they only solve half the problem? Generally I use the circuit shown by Richard Burns (above), so the line supply to the bathroom lighting and fan goes via a 3A fuse before any switches. Whether you use a single plate solution or two separate accessories makes no difference.

 

[westward10]

Why do they only solve half the problem? Generally I use the circuit shown by Richard Burns (above), so the line supply to the bathroom lighting and fan goes via a 3A fuse before any switches. Whether you use a single plate solution or two separate accessories makes no difference.

I agree but do the manufacturer make that clear. Be interesting to undertake a study, take 10 sparks, give them the necessary parts and cable and see how many come up with the correct circuit.

 

[Toneyz]

Correct me if I'm wrong the 3A fuse is as posted for overload protection the 3 pole switch for isolation. I think the fan is powered via live/line and neutral therfore fuse in perm.live the switch wire just triggers the timer and not powering the fan motor.

 

[Richard Burns]

Correct me if I'm wrong the 3A fuse is as posted for overload protection the 3 pole switch for isolation. I think the fan is powered via live/line and neutral therefore fuse in perm.live the switch wire just triggers the timer and not powering the fan motor.

The fuse is not required to protect the switched line from overload, however if the fuse blows and the fan stops and then someone is working on the fan they will be expecting that the fuse has removed power from the fan however the switched line would still be live and subject someone to the risk of shock.
Whilst you might say anyone with any sense will switch off the isolator, since these are domestic fans non professional persons are likely to be investigating and therefore may be subject to a shock risk.