Bathroom fan isolation

[smiffy911]

Without digging out my O.S.G am I right in thinking no triple pole isolation switch is required if there is a window in the bathroom thus lighting circuit can be isolated for fan maintainance.

 

[Octopus]

Without digging out my O.S.G am I right in thinking no triple pole isolation switch is required if there is a window in the bathroom thus lighting circuit can be isolated for fan maintainance.

Manufacturers instructions over rule the BGB

 

[smiffy911]

BGB???????????
Sorry for my ignorance

 

[Octopus]

BGB???????????
Sorry for my ignorance

big green book. BS 7671 latest version.

 

[smiffy911]

Of course............
Although i refer to it as EEBGB (extremely expensive big green book)

 

[Octopus]

Of course............
Although i refer to it as EEBGB (extremely expensive big green book)

So when you read the instrutions you'll need DP isolation and a 3A fuse!

 

[Guest55]

Without digging out my O.S.G am I right in thinking no triple pole isolation switch is required if there is a window in the bathroom thus lighting circuit can be isolated for fan maintainance.

correct.

now awaiting the backlash and much hand-wringing.
;-)

 

[Guest55]

Manufacturers instructions over rule the BGB

not in my world they dont.
in my world the Cheap China Fan Company does not overule bs7671.
;-)

 

[Octopus]

correct.

now awaiting the backlash and much hand-wringing.
;-)

ha ha Biff. Post #2 sets out the expectation!

 

[chrish_1977]

Fitted a fan today, no need for 3a fuse

 

[Octopus]

Fitted a fan today, no need for 3a fuse

what model?

 

[iD1985]

I don't fuse fans because I normally fit timer fans & I'd have to fuse the permanent & switched live. So 2 fuses. I always use a fan isolator though

 

[Octopus]

I don't fuse fans because I normally fit timer fans & I'd have to fuse the permanent & switched live. So 2 fuses. I always use a fan isolator though

No you wouldn't, you can use a single fuse

 

[lurch]

if fan instructions ask for 3 amp fuse and you dont fit, then if there is an issue with fan overhating and subsequent fire then said spark is liable if proven by insurance assesors. In my eyes only way to do it is to isolate bathroom lighting with switch fuse spur.

thoughts please

 

[iD1985]

You can use one fuse if you put the whole bathroom through it. Then the perm & switched lives would both be fused

 

[thomas-1981]

How is a three amp fuse going to stop a fan 'overheating'?

 

[lurch]

it wont stop it from overheating, but it has a characteristic of going pop if fan is drawing too much design current! its called overload protection

 

[onions1066]

I think you are referring to if the fan stalls then there is a chance of overheating no through normal operation, this subject has been discussed to death before but vent axia range are now internally fused so no need for fused spur just triple pole isolator

 

[lurch]

I think you are referring to if the fan stalls then there is a chance of overheating no through normal operation, this subject has been discussed to death before but vent axia range are now internally fused so no need for fused spur just triple pole isolator

i fitted a fan a couple of weeks ago that asked for 6a. It was a retrospective fot so the extra cost outweighed the hassle of fitting spur. . .

 

[robsparky1975]

You can know buy a 3 pole isloator with intrgral fuse holder(comes as grid type setup)about £6 seen them at the local wholesalers.

 

[lurch]

You can know buy a 3 pole isloator with intrgral fuse holder(comes as grid type setup)about £6 seen them at the local wholesalers.

be interested to see this

 

[robsparky1975]

see if i can get a pic

 

[lurch]

see if i can get a pic

cheers

 

[D Skelton]

OOOOH my favourite topic!

But I can't be bothered. Too bored of this debate now

 

[kingeri]

The 6a MCB would probably trip before the 3a fuse blew anyway.