Shower fan isolation switch

[rhd]

Question:  I need to fit a shower extractor fan.  I will do this by connecting via the main bathroom light and siting the fan in the ceiling.  All recommendations are that there should be an isolation switch for the fan.  Can you please advise why a separate isolation switch is required for the fan, rather than relying on the isolation switch for the circuit, to include the main bathroom light.  Why is it important for the fan to have its own separate isolation switch?  Secondly, since i will be fitting the fan in the ceiling and all electrics being connected in the attic above, is there any reason why the isolation switch cannot be in the attic?  The reason being that i have no need, by siting in the ceiling, to chase cables into walls.

thank you

 

[Blue Duck]

Question:  I need to fit a shower extractor fan.  I will do this by connecting via the main bathroom light and siting the fan in the ceiling.  All recommendations are that there should be an isolation switch for the fan.  Can you please advise why a separate isolation switch is required for the fan, rather than relying on the isolation switch for the circuit, to include the main bathroom light.  Why is it important for the fan to have its own separate isolation switch?  Secondly, since i will be fitting the fan in the ceiling and all electrics being connected in the attic above, is there any reason why the isolation switch cannot be in the attic?  The reason being that i have no need, by siting in the ceiling, to chase cables into walls.

thank you

RCD's & part pee.

There are many reasons that it needs an isolation switch but mainly for me it's that it makes the fan easier to change when it goes kaput. 

It may also need fusing down, check Manufacturers Instructions.

 

[Hefferl]

Inline fan in loft with adjacent isolation - just a grille in bathroom ceiling.

No RCD needed no Part P I believe.

 

[Murdoch]

Inline fan in loft with adjacent isolation - just a grille in bathroom ceiling.

No RCD needed no Part P I believe.

Hum.... you are adapting the circuit which "serves" the bathroom and thus RCD protection for the circuit is required,

As for isolation - I would read the manufacturers instructions to see if fusing down is also required - most do.

I would agree that this doesn't need Part P

 

[Rob_the_rich]

Inline fan in loft with adjacent isolation - just a grille in bathroom ceiling.

No RCD needed no Part P I believe.

Unless the new feeds are taken from the light fitting or pull switch enclosures within the bathroom. But it can all be wired in the loft using JBs. Agreed.

Can be quieter too.

 

[Hefferl]

Hum.... you are adapting the circuit which "serves" the bathroom and thus RCD protection for the circuit is required,

As for isolation - I would read the manufacturers instructions to see if fusing down is also required - most do.

I would agree that this doesn't need Part P

Interesting. Very likely that this circuit that serves the bathroom is also the circuit that serves the loft lighting. How does this alteration differ from adding an extra light in the loft, Would the extra light in the loft need an RCD?

 

[rhd]

Unless the new feeds are taken from the light fitting or pull switch enclosures within the bathroom. But it can all be wired in the loft using JBs. Agreed.

Can be quieter too.

Thank you for all the input thus far.  My intention is to use a fan incorporating a humidistat, hence i will not be going down the inline fan route.  I also believe that I have RCD on the circuit, at the main fuse box (but will confirm). The feeds for the fan will be taken from the light fitting in the ceiling of the bathroom, but wired from above in the loft space.  The consensus therefore seems to be an isolation switch should be fitted, but only for ease of replacing or maintaining the fan when necessary.  Can this not be done by isolating the circuit back at the main fuse board again with the same result?

 

[Murdoch]

Why do you think you need a humidistat fan? 

Double pole isolation. Is good practice for all fixed appliances

 

[ProDave]

The question appears to be why fit a fan isolator switch?

The answer is not simple.

Now, for a timer fan, that runs on for some time after it is turned off, it does make a great deal of sense, but for a fan that just comes on and off with the light with no over run, I am not sure.

If "replacement" is the reason given, then by the same argument, every light fitting that is wired "loop at the light" should also have an isolator switch next to it so you can replace the light fitting should it not?

I believe the reason it's generally done, is some other regulation (NOT BS7671) makes reference to the need for a local isolator next to a "motor".and that regulation has been applied to extract fans.  Now while it makes sense to have an isolator next to a big air conditioning fan that's operated remotely, so the person changing the drive belt can be sure it won't start while he is doing so, I remain to be convinced that the same is really needed for a tiny domestic bathroom fan.

My last point on the subject, In rental properties I strongly advice against having a fan isolator, as it is well proven that tenants will turn the fan off because the noise annoys them, and then complain to the landlord about the damp and mould in the bathroom.

 

[rhd]

Answers: 

1. Why humidistat: so the fan need not come on every time the light is switched on, but will do, and remain on with the over-run timer, when the shower is used.

2. This is not a replacement.  We recently had a shower fitted to the room, and now unsurprisingly have a humidity problem. The fan will be a new installation in the ceiling, wired from the main ceiling light fitting, but via the loft.

3. The loft light is on a different circuit.

 

[NozSpark]

Be warned that electrical work inside a bathroom requires notification under Part P of the building regulations (which are law)... failure to comply with Part P can cause difficulties if you ever sell your house,,, never mind the rest

However,,,, make sure that you vent it outside and not just into your loft as moist air can really make a mess of your roof

 

[Andy™]

only inside the zones in england

 

[NozSpark]

only inside the zones in england

 

[Blue Duck]

B&Q making the rules now...

 

[Andy™]

im surprised the scams allowed it, the amount they must be losing from notifications

 

[Murdoch]

im surprised the scams allowed it, the amount they must be losing from notifications

Hum....the Niceic and Elecsa doubled their fees with the mandatory warranty!

Stroma didn't

 

[Andy™]

but for me, its now costing a lot less (& less hassle). previous to that change i used to have to notify 2-3 jobs per week. it immediately dropped to almost 0, last notification was sometime last august, and i havent been with a scam since sept

 

[Davethsparky]

there is no requirement for an isolation switch, but a means of isolation is a damned good idea.

personally I fit a 4 pin socket for inline fans to provide isolation and easy removal for maintainence/replacement. Plus it's an easy way to convert from solid cable to flex to make the final connection to the fan.

 

[pewter]

You dont have to have an isolator,

As you are fitting a humidistat fan which will probibly start running for ages when you dont want it to, it would be worth fitting an isolator.

personally i would just gor for a fan with a timer and no isolator.

 

[Murdoch]

And make sure, what ever fan you do fit, that there is adequate airflow under the door into the room, or adding the fan will be pretty pointless!