bathroom extractor fan

[gavin.sibley]

Hello all,

Just a quick one, I think I know the answer anyway but it's one of those I'm doubting myself haha

I wired up a extractor fan In a customers bathroom, taking a feed from the light via a 3 pole isolator and onto the fan.

The fan went faulty so I went back to test and power was still getting to the fan on both live and switched love conductors, and all connections were right, so told customer it was a faulty fan.

At this point we introduce the plumber, who supplied the fan In the first place.

He is now saying that the fan has bed wired up wrong and isn't allowed to be wired in this way.

Just wondering if anyone can tell me whether this is right or wrong, as I said I think I know what's coming but he's making me doubt myself.

Cheers,
Gavin

 

[MDJ]

Hello all,

Just a quick one, I think I know the answer anyway but it's one of those I'm doubting myself haha

I wired up a extractor fan In a customers bathroom, taking a feed from the light via a 3 pole isolator and onto the fan.

The fan went faulty so I went back to test and power was still getting to the fan on both live and switched love conductors, and all connections were right, so told customer it was a faulty fan.

At this point we introduce the plumber, who supplied the fan In the first place.

He is now saying that the fan has bed wired up wrong and isn't allowed to be wired in this way.

Just wondering if anyone can tell me whether this is right or wrong, as I said I think I know what's coming but he's making me doubt myself.

Cheers,
Gavin

Never listen to a Plumber, one thing though, you should have 3 amp fuse protection to the fan.

 

[gavin.sibley]

That's what I thought? Is there a reg that says dont listen to plumbers.....? In not I think it's an idea!

So how would you suggest fusing the circuit down to 3 amps? I have never seen 3 pole switched fused spurs....

 

[MDJ]

That's what I thought? Is there a reg that says dont listen to plumbers.....? In not I think it's an idea!

So how would you suggest fusing the circuit down to 3 amps? I have never seen 3 pole switched fused spurs....

Yup you can get them, ask your wholesaler bud

 

[tlangdon12]

The plumber isn't the definitive source on how to wire the fan. The manufacturer is. If you followed the manufacturer's instructions including all requirements such as the fuse to protect the device, then you are ok.

 

[tlangdon12]

You can make up a three pole fused isolator using items from the Scolmore Click Minigrid range. Eg parts nos CMA403 + MD047WH + MD020WH.

 

[telectrix]

youm could also feed the bathroom light through a 3A FCU .

 

[EastAnglian]

I now regularly put a 3A FCU and 3 pole isolation switch side-by-side into a dual box when either fitting new or retro-fitting extractor fans, and supply both light and fan via this supply.

 

[davethsparky]

So when the fan goes wrong and takes the fuse out the customer loses the light aswell, could be pretty dangerous if they are in the shower at the time!
And don't forget the 3amp fuse going when the lamp blows leading to the customer putting a 13amp in to fix it!
Any more bad ideas you care to share with us?

 

[mark ju]

Never seen a bathroom fan fused down. But I know the issue gets raised every now and then.
probably still will be for years yet.
As for the pipe basher.....never listen to these people. They lead you astray. If they had more than a brain cell they'd be sparks. But they ain't!

 

[staggie65]

You can make up a three pole fused isolator using items from the Scolmore Click Minigrid range. Eg parts nos CMA403 + MD047WH + MD020WH.

Good post, I'll use this

 

[Geoffsd]

I think it is generally accepted that you don't need to fuse the switched live as it can't cause an overload.

 

[decolad69]

Hello all,

Just a quick one, I think I know the answer anyway but it's one of those I'm doubting myself haha

I wired up a extractor fan In a customers bathroom, taking a feed from the light via a 3 pole isolator and onto the fan.

The fan went faulty so I went back to test and power was still getting to the fan on both live and switched love conductors, and all connections were right, so told customer it was a faulty fan.

At this point we introduce the plumber, who supplied the fan In the first place.

He is now saying that the fan has bed wired up wrong and isn't allowed to be wired in this way.

Just wondering if anyone can tell me whether this is right or wrong, as I said I think I know what's coming but he's making me doubt myself.

Cheers,
Gavin

You learn something every day !

 

[davethsparky]

I think it is generally accepted that you don't need to fuse the switched live as it can't cause an overload.

What a load of rollocks, if the fuse pops on the perm live and the fan stops working then our poor homeowner might quite reasonably assume the thing is dead and receive a potentially fatal shock from the switched live which isn't as dead as it appears!
What is it with people who can't see past the end of their own nose? Why can't people learn to think ahead and forsee the potential pitfalls of their foolhardy plans?

 

[EastAnglian]

So when the fan goes wrong and takes the fuse out the customer loses the light aswell, could be pretty dangerous if they are in the shower at the time!
And don't forget the 3amp fuse going when the lamp blows leading to the customer putting a 13amp in to fix it!
Any more bad ideas you care to share with us?

So tell me then, how to YOU install a bathroom fan "to take account manufacturers' instructions" (Regs 134.1.1 & 510.3) when said instructions indicate that both Line & Switched Line inputs must be protected by a 3A fuse?

Just like any other FCU I will always fix a printed label stating "Max fuse rating 3A" (or what ever value is appropriate) - Reg 533.1. If a customer chooses to ignore the label and fit a 13A fuse then it is them, not me who is acting in an incompetent way (Reg 134.1.1).

With this set-up if the fan goes wrong it will take out the fuse and the bathroom light, but possibly not a 6A MCB, depending on how fast the fuse ruptures. However, in the alternative scenario the same failure will definitely take out the circuit MCB which is most likely protecting ALL the upstairs lighting. Now call me a thickie if you like, but if you are in the shower and one light goes out as a result of a fault I tend to think that's better than all the lights on the floor going out.

The isolation switch is there to enable the fan to be isolated (the clue is in the name), so that it can be worked on independently of the light.

Mark Ju .... never mind what you have seen elsewhere, next time you unpack an extractor fan take a moment to read the manufacturer's installation instructions. If they say it must be fused on a 3A circuit, then you must install a 3A fuse. Simples. If you choose not to comply with those instructions then you will have to enter it as an exception on the Minor Works Certificate or EIC, but good luck if you ever have to justify that decision in court.