Bathroom SELV extractor operation

[wingit]

That makes me wonder if the 12 controller that switches to 240V would be safe to be left on continuously.

That's what they are designed for.

Fans of that type are usually also wired to the lighting, so that when the light is on, the fan runs regardless of humidity, and continues to run when the light is off for a few minutes due to the adjustable timer.
At any time if the humidity level is too high, the fan will operate regardless of the timer or lights.

Humidity sensors are often more trouble than they are worth, as humidity varies due to the weather and time of year.
It's also unlikely that an expensive SELV fan is required anyway, and given that the controller is usually fitted into the loft, an inline extractor would be a much better option.

Thanks flameport, I would have gone with the inline fan option, but there is an existing 240V fan in place in the wall and it's much easier just to replace that. Considering the location of the fan an IPX7 (SELV) fan rather than an IPX4 (currently) seems worth the extra cash. I think I've made up my mind that I'll have a simple solution without humidistat, just on/off at the wall switch

 

[EFLImpudence]

That was hard work.

You don't need SELV or IPX7 for zone 2 - or zone 1, for that matter.

 

[wingit]

That was hard work.

What for you or for me? For all the contributors too I imagine!

You don't need SELV or IPX7 for zone 2 - or zone 1, for that matter.

Yeah, but you know, belt and braces keep my trousers up much more safely

 

[ban-all-sheds]

Wiring for the 12v switch: http://altima.co.uk/DbFiles/File_10620_pdffile.pdf
Operates a remote controller device which switches 240V. Can be used for many different types of lighting and also a fan.

You did better than I - I found both the seller's and the maker's websites very unforthcoming with information, but I did find something which talked about a dimmable LED driver which could be controlled by the dimmer switch the OP linked to. You have to figure that if a 230V powered LED driver can be controlled by a 12V dimmer that the dimmer is not a general purpose one.

 

[ban-all-sheds]

I think I've made up my mind that I'll have a simple solution without humidistat, just on/off at the wall switch

You still won't know if it is on or off, because you'll have to use a fan with a timed overrun.

Firstly because you actually need that type of ventilation device.

Secondly because chances are that the only way a dimmer switch can be used to control a fan is when the dimmer is providing the switched live trigger, not the actual working voltage. If you put the output from a dimmer into a fan transformer, don't expect it to work.

 

[wingit]

You still won't know if it is on or off, because you'll have to use a fan with a timed overrun.

Firstly because you actually need that type of ventilation device.

Secondly because chances are that the only way a dimmer switch can be used to control a fan is when the dimmer is providing the switched live trigger, not the actual working voltage. If you put the output from a dimmer into a fan transformer, don't expect it to work.

Yes, thanks, I'd come to the same conclusion.

I have two options as I see it:
1) Get a fan with the shortest overrun possible, I've seen 1 minute ones, so not long to wait.
2) Fit a small indicator light on the same circuit (I think I'll do that in the ceiling above the fan or above the switch) which only comes on when the button is on, and when in overrun the light is off.

The second option would be quite nice as the user could press the button on and off again just before leaving the bathroom, check the light and be sure it was off, and leave the fan to run its overrun timed period. Just like a pull cord operation but more convenient, given the location of the fan.

 

[ban-all-sheds]

And you know that a 1 minute overrun will be enough for the fan to do the job you need it to do because..... ?

 

[wingit]

And you know that a 1 minute overrun will be enough for the fan to do the job you need it to do because..... ?

ermmm... seems like a trick question.. I give up

 

[ban-all-sheds]

The whole point of a fan with an overrun is that you finish using the room, turn the fan off, and leave.

And the fan carries on running for long enough to completely clear all the moist air out of the room.

It's not a trick question, unless you simply haven't thought about it - how do you know that a mere 60 seconds will be long enough for the fan to completely clear all the moist air out of the room?

 

[wingit]

The whole point of a fan with an overrun is that you finish using the room, turn the fan off, and leave.

And the fan carries on running for long enough to completely clear all the moist air out of the room.

It's not a trick question, unless you simply haven't thought about it - how do you know that a mere 60 seconds will be long enough for the fan to completely clear all the moist air out of the room?

Agreed. If I chose the 60 seconds overrun set up then the fan would just be used in a different way, finish using the bathroom, turn fan on, go and do other stuff for ten minutes then come back and turn it off. I wouldn't rely on one minute being enough to clear a room of steam. It's not an optimal solution as it relies on remembering to turn it off after the desired operating time, but it would do the job.

 

[EFLImpudence]

This thread is ridiculous.

Are you being deliberately awkward?



Get a switch which looks different when off than it does when on.
There are lots

 

[wingit]

This thread is ridiculous.

Are you being deliberately awkward?



Get a switch which looks different when off than it does when on.
There are lots

The switch has already purchased. The questions have been genuine, and a solution found. I have not been deliberately awkward and I find your post offensive. I've had to explain myself multiple times because people don't read the full thread, but I don't mind doing that.

 

[EFLImpudence]

NO low voltage switches are allowed in zone 2.

If you mean extra low voltage, 12V, then:

Why does it have to be in zone 2, anyway?

 

[wingit]

NO low voltage switches are allowed in zone 2.

If you mean extra low voltage, 12V, then:

Why does it have to be in zone 2, anyway?

There's nowhere in the bathroom that I can place the switch that is outside of the zones.
This switch is suitable for zone 2 in a bathroom http://www.electronicsarena.co.uk/c...-bathroom-switch-double-plate-2-button-dimmer.

 

[winston1]

Regarding pull cords, the wife doesn't like them :/ .

I've heard that a number of times. I always say it's a legal requirement to prevent you getting killed. That shuts them up.