Hi,
Currently, my bathroom has a fan which switches along with the light and stays on on a timer afterwards. Most of the time, this is unnecessary - if I fill up a glass of water before going to bed I don't need a fan waking up everyone else in the house.
As part of my bathroom refit, I'm planning to disconnect the fan totally from the lighting, and instead switch it via a flow switch on the shower supply. I also want a manual button strategically positioned next to the toilet flush :-). This would be a momentary switch so that the fan starts and then runs-on on the timer.
My question is how to handle the wiring of this switch. I currently have a nice brushed-steel button that would look the part. It happens to be rated to 250v/5a, but AFAIK is not IP-rated. I also have a relay that will switch a mains supply from a 6-12v signal current. One approach would be to have the relay in a suitable enclosure in the roof space above the bathroom, with the button controlling the low-voltage side from below. This keeps mains out of the bathroom, but is it acceptable from a regs point of view? I'm confident that I can built it safely, but these aren't quite the same thing :-)
Alternatively, I could buy an IP-66 button (eg MP0031,
Cheers,
Pete