Extractor Fans

[Rob_the_rich]

I agree with ProDave about rental properties. Tenants often won't even open a window if there is one. No need for a fan isolator unless the MI specify it. Switching off the OCPD for the lighting circuit (locked off/removed, unless CU is in the bathroom, eek) does the job for mechanical maintenance, why would you need the bathroom lights on when working on the fan? you have a torch/sitelight. That is surely just for convenience.

But the OP might consider fitting one, the light switch can turn on the fan with say a 10 minute over-run, and the fan can be switched off by the isolator if not needed.

 

[ProDave]

I think. I stress. I think that is against regulations. If the fan is on with the lights it should have a means of isolation without turning the complete circuit off.

This fan isolation thing seems to stem from reg 537.3, particularly 537.3.1.1

It all depends whether you think a typical bathroom fan is capable of physical injury or not.  Having stuck my fingers in the blade of a rotating bathroom fan, it's never been more than an "ouch" and no physical injury occurred.

So personally my opinion is to fit a fan isolator in normal installations, but omit it in rental properties because of the number of times I have seen them switched off (and then the tenant complaining of damp)

there is another reg that I can't find right now that makes specific reference to a local isolator for each "motor"

 

[Sidewinder]

537.4.2.1?

 

[ProDave]

537.4.2.1?

Not unless you were thinking of a big red mushroom button next to each fan.

 

[Essex1]

To be honest I was under the impression it was to do with specifically isolating anything that was fed from a lighting circuit to allow said item to be worked on without turning off the complete lighting circuit.  Having checked today I cannot find it so it must have been a 16th thing that has now been omitted.  It may even be a EaW regulation also?

 

[Sidewinder]

Not unless you were thinking of a big red mushroom button next to each fan.

That would be nothing to do with a big red mushroom button, it would be to do with an isolator being able to break FLC of the motor, an e-stop button can never do that.

 

[ProDave]

I do remember a reg that made specific reference to a local isolator switch next to a motor, and always thought that was why a fan isolator was fitted.

I'm off out now but I'll have a look in some of the older regs books later to see if it is something that has quietly dropped off.

  It may even be a EaW regulation also?

Perhaps that is where the reference to an isolating switch next to each motor is?

 

[Rob_the_rich]

oh, BYB 132.15.202 "every fixed electric motor shall be provided with an efficient means of switching off, readily accessible, easily operated and so placed as to prevent danger"

Rather scuppers my earlier post.

A danger could be hair getting entangled in the fan, the switch would have to be within arms reach in this case and might conflict with zones.

 

[ProDave]

That's the one I was looking for.

So is a risk assessment that a bathroom fan poses no danger good enough reason to ignore it?

My guess is the reg is aimed at proper size motors that are a real danger if for instance they started up while some guy was busy replacing the drive belt, so it's sensible to have some local isolation, and we are just all being a bit silly and applying this to a bathroom fan.

Can one not argue if it's switched from the bathroom light switch, that it already has a convenient and efficient means of switching off?

 

[Rob_the_rich]

if it has an overrun then it will have a permanent live. Also how do you lock off a light switch if it is outside the bathroom? I know some fan isolators can be locked off.

 

[ProDave]

You don't have a local isolator for a ceiling rose that has a permanent live do you? you isolate at the CU to work on that.

It is purely because it is a "motor" that people fit the local isolator, not because we need this extra isolation to do electrical work on it.