Bathroom fans and switching fusing requirements.

[sw-electrical]

Hi All, I know this has probably been covered in various forms many times before, but I'm trying to achieve a simple effective solution to a number of problems that bathroom fans have.

With reference to bathroom fans, lights,isolation and fusing requirements, does anyone see any problems with the following setup. Drawing attached (i hope).

The diagram and fittings achieve the following
1) 3 pole isolation for maintenance of fan with light remaining on.
2) Fuse requirement of both the switch and permanent fan lives using 1 fuse only.The light remains switcheable, it is not locally fused.
3) Loop in/out at the switch
4) A single T&E at the light fitting (or 2 T&E if 2nd light required), making the fitting of most IP rated bathroom lights a lot easier.
5) Incorporates the requirements of Reg 537.3.2 and EWR (Regulation 12) Means of isolation to be secure.


The switch fittings will be a 20A DP grid switch with a separate Fuse holder, sitting in a 2G frame in 1G 35mm box.
I'm not sure if a standard switched FCU can be used as i think the fuse is after the DP switch and the link is built into the FCU and can't be tapped into.

Comments please. Thanks

 

[telectrix]

had a quick gander. obviously your electrical skills are better than your artistry. can't see a fault with how that's wired.

 

[Top Cat]

Had a slightly longer gander (that's why Tel beat me to it) and agree with Tel (wiring and artistry!). Quite clever actually, unless you want a pull switch!

 

[sw-electrical]

The artistry was done quickly on a dry wipe board with limited pen colours, but forgot to mention that bits were ommitted for clarity. I then took a picture and posted it on here. Thanks

 

[Top Cat]

The artistry was done quickly on a dry wipe board with limited pen colours, but forgot to mention that bits were ommitted for clarity. I then took a picture and posted it on here. Thanks

Forgiven! Actually wouldn't have done any better myself, just a bit of humor on our part.:icon7:

 

[HandySparks]

Looks like a good solution to the problem if you don't need to use a pull switch.

Would a double pole gridswitch be heavier to operate than a typical light switch? (this may or may not matter)

edit: Beaten to it by TC

 

[sw-electrical]

This particular scenario was for a switch outside the room, but i forgot about a pull switch option. But that is why i posted on here. Oh well, at least i can practice my artist skills again.

 

[telectrix]

i have not yet mastered the wizardry of transterring a design from the back of a beermat to the computer.

 

[Top Cat]

i have not yet mastered the wizardry of transterring a design from the back of a beermat to the computer.

You haven't mastered the wizardry of spelling yet! Been waiting for this since you got me on pallets! Lol

 

[Knobhead]

Ding Ding, Round Two!

 

[Guitarist]

Is there any reason why you don't want the light included on the fuse? It's far neater to use an FCU for the circuit than split to a separate fuse-holder. Obviously your call tho

 

[Top Cat]

Ding Ding, Round Two!

Trouble is Tony, what do you think my chances are against Tel in the p** taking competition?!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[sw-electrical]

The main reason for light to continue working is so that you don't have to work with a torch in a non window room. Just trying to cover all options in one working solution.

The regs are a bit vague regarding requirements for fans other than isolation in general.

I personally think that the equipment manufacturers need to consider designing more suitable switched fuse units to accomodate some of these "assumed practices", such as more recent RCD'd FCU's. Why not have a 3 Pole switch with 2or 3 fuse units incorporated into it.
Safety and practicality should run in unison with the regs, not just meet the minimum requirements. Another example of recent forward thinking is the ashley J series junction boxes. These are just so much more practible than the old round JB's, which i find almost useless.

Maybe i'm being a bit padantic, these problems have been around for a long time, but some of the solutions are only just coming to the market.

 

[Strima]

Why don't they just manufacture fans with fuse holders in them?

 

[Risteard]

The main reason for light to continue working is so that you don't have to work with a torch in a non window room. Just trying to cover all options in one working solution.

The light will continue working if you loop through an unswitched FCU with a 3A BS 1362 fuse and bring the fused line to the light and then a switch drop from it with the fan connected through a triple pole isolator.

 

[Guitarist]

The main reason for light to continue working is so that you don't have to work with a torch in a non window room. Just trying to cover all options in one working solution.

The regs are a bit vague regarding requirements for fans other than isolation in general.

I personally think that the equipment manufacturers need to consider designing more suitable switched fuse units to accomodate some of these "assumed practices", such as more recent RCD'd FCU's. Why not have a 3 Pole switch with 2or 3 fuse units incorporated into it.
Safety and practicality should run in unison with the regs, not just meet the minimum requirements. Another example of recent forward thinking is the ashley J series junction boxes. These are just so much more practible than the old round JB's, which i find almost useless.

Maybe i'm being a bit padantic, these problems have been around for a long time, but some of the solutions are only just coming to the market.

A triple pole isolator is just that mate... an isolator, so that you can work on the fan with the light still on...
All that said, I usually have my headtorch on anyway