3A fuse for bathroom fan

[wiresnpliers]

Hi All,

Like many practicing electricians I have been frustrated that there is not a simple solution when wiring a bathroom fan with timer and the manufacturer's instructions say that it must be fused with one 3 amp fuse. I believe I have come up with the solution, which I have patented, what I'm struggling with (because I'm a sparks, not a manufacturer) is how to get this thing made, or if it was made, whether anyone would use it. I've attached the wiring diagram, which is pretty self explanatory. Feed back and/or any ways into manufacturing would be appreciated!

 

[LastManOnline]

It could happen if manufacturers start fitting motors to ceiling roses.

Did I misunderstand you? The triple pole isolator is not directly related to the motor.

 

[LastManOnline]

Which presumably means any future works on the fan are done in the dark.....

Which is precisely the situation you would have replacing a ceiling rose in the bedroom next door to the bathroom. Need a head torch?

 

[dodger421]

Which is precisely the situation you would have replacing a ceiling rose in the bedroom next door to the bathroom. Need a head torch?

Unusual for a bedroom not to have a window though.

Don’t the applicable building regs stipulate the fan must be able to be isolated separately from the sole source of light if the bathroom doesn’t have a window?

 

[nicebutdim]

Did I misunderstand you? The triple pole isolator is not directly related to the motor.

I couldn't see how fans could be compared to ceiling roses. The former has its permanent live connected for overrun of a motor, whereas permanent live at a ceiling rose is simply a junction.

 

[LastManOnline]

I couldn't see how fans could be compared to ceiling roses. The former has its permanent live connected for overrun of a motor, whereas permanent live at a ceiling rose is simply a junction.

Correct. But my point related not to the purpose of the permanent live (be it ceiling rose or fan) but to the fact that an electrician deals effortlessly with the replacement of a ceiling rose without the need for a local isolator so why can we not do similarly with a fan?

 

[DPG]

Correct. But my point related not to the purpose of the permanent live (be it ceiling rose or fan) but to the fact that an electrician deals effortlessly with the replacement of a ceiling rose without the need for a local isolator so why can we not do similarly with a fan?

But an extractor is a more complicated mechanical assembly with various moving parts. Also may need cleaning out periodically.

 

[dodger421]

Correct. But my point related not to the purpose of the permanent live (be it ceiling rose or fan) but to the fact that an electrician deals effortlessly with the replacement of a ceiling rose without the need for a local isolator so why can we not do similarly with a fan?

I’d argue it’s equally for the convenience of the occupier. A fan motor is more likely to fail at some point than a ceiling rose with no moving parts and without a DP or TP isolator that failed component may well result in a home being plunged into darkness until the fan can be replaced.

Less likely with modern boards and multiple lighting circuits, but still possible in smaller properties or older ones.

 

[LastManOnline]

But an extractor is a more complicated mechanical assembly with various moving parts. Also may need cleaning out periodically.

OK. But your point is.......

 

[LastManOnline]

I’d argue it’s equally for the convenience of the occupier.

It's an argument. Not sure I, m won over by it. I, m all for local isolation of course. But I, m all for consistancy in its application too.

 

[dodger421]

It's an argument. Not sure I, m won over by it. I, m all for local isolation of course. But I, m all for consistancy in its application too.

Consistency? Have you read BS7671?

In seriousness I see a fan isolator as being needed for same reason you need accessible isolators for kitchen equipment (the building standards in Scotland do anyway); It gives occupiers a safe and convenient means of isolating equipment that’s likely to develop a fault.

 

[Baddegg]

This thread is comedy gold, sorry. Strikes me that if it's really such a big deal, then given that in a new build it's all LED lighting anyway, just stick a 3A CPD at the start of the whole lighting circuit, job done.

That’s what I do.....

 

[DPG]

OK. But your point is.......

You said we manage without an isolator for a rose, but not a fan. And I'm saying that a motorised appliance needs an isolator for maintenance.

Or in case of a fault of course, as mentioned by others.

 

[nicebutdim]

Correct. But my point related not to the purpose of the permanent live (be it ceiling rose or fan) but to the fact that an electrician deals effortlessly with the replacement of a ceiling rose without the need for a local isolator so why can we not do similarly with a fan?

As others have stated, I never considered fan isolators being fitted for the convenience of electricians, but for occupants who need to safely isolate when fan motor is failing or has failed.

Obviously local isolation is also important for those home owners or tenants who wish to propagate mould.


I enjoy reading these discussions, with back and forth of differing opinions. Generally it's read only for me, but I wasn't quite getting why fans and ceiling roses were being compared in terms of local isolation.

 

[LastManOnline]

You said we manage without an isolator for a rose, but not a fan. And I'm saying that a motorised appliance needs an isolator for maintenance.

Or in case of a fault of course, as mentioned by others.

They are all reasonable points. But the triple pole isolator was introduced originally, not for the reasons you mention above (though valid) but because of the perceived dangers of the permanent live at the fan itself, should someone attempt to change or service the fan. Of course the exact same dangers are present at a ceiling rose. An amateur would be at risk in both scenario, s.

 

[nicebutdim]

They are all reasonable points. But the triple pole isolator was introduced originally, not for the reasons you mention above (though valid) but because of the perceived dangers of the permanent live at the fan itself, should someone attempt to change or service the fan. Of course the exact same dangers are present at a ceiling rose. An amateur would be at risk in both scenario, s.

I get where you're coming from and it's easier to access live parts in a ceiling rose, than in a fan.

On the other hand, routine household maintenance at a ceiling rose would only involve replacing a lamp which is far removed from the rose. While a home owner may decide to change a failed fan, most would be considerably less likely to do this and would simply switch it off in the short (or longer) term.