Looking for a cheap solution to restrict the extractor fan in the bathroom to not operate with the lights in the middle of the night...
Options:
1. Separate fan switch independent of the light switch - might not always be switched on when needed during the day, and off afterwards.
2. Remote humidistat switch - expensive to buy and difficult to retro-fit as walls have already been fully-tiled.
3. Din rail timer in a wall-fix enclosure - not quite as expensive but similar issues to wiring as below...
4. 230v programmable timer to restrict permanent L to fan to daylight hours only - ie, by providing a separate timer-switched L to the permanent L of the fan (independent of the usual switched L control from the light switch).
If considering option 4, can a simple 13A programmable "plug-in" timer be used? Admittedly this would have a number of further questions:
1. As the plug-in timer is intended for 13A mains use, this would require a 13A socket and 13A plug (ie, a 13A plug into the 13A timer into a 13A socket) on a 5A lighting circuit. Is this acceptable? If the plug is removed, it could have unsuitable equipment plugged in? (Even if labelled as 5A only and located in a locked box in the garage, etc.)
2. Do plug-in timers just switch the L (SP) or both L & N (DP). If SP, can the N wires on both sides of the plug-in timer (ie, to the 13A socket and from the 13A plug) be connected in an adjacent 4T junction box? This would then be wired to a 3C+E cable, with permanent L, timer-switched L and N back to a 6T junction box next to the ceiling fan to pick-up the switched L from the bathroom light switch, and on to a 3T fan isolator switch then fan. Even if DP, could the N's still be connected on both sides?
3. Are fans classed as induction loads? Does this have an impact on what timers can be used?
It's not as pretty a solution as a fixed timer, but are there any reasons that this shouldn't work?
Not sure that I've managed to explain it all too well!
Options:
1. Separate fan switch independent of the light switch - might not always be switched on when needed during the day, and off afterwards.
2. Remote humidistat switch - expensive to buy and difficult to retro-fit as walls have already been fully-tiled.
3. Din rail timer in a wall-fix enclosure - not quite as expensive but similar issues to wiring as below...
4. 230v programmable timer to restrict permanent L to fan to daylight hours only - ie, by providing a separate timer-switched L to the permanent L of the fan (independent of the usual switched L control from the light switch).
If considering option 4, can a simple 13A programmable "plug-in" timer be used? Admittedly this would have a number of further questions:
1. As the plug-in timer is intended for 13A mains use, this would require a 13A socket and 13A plug (ie, a 13A plug into the 13A timer into a 13A socket) on a 5A lighting circuit. Is this acceptable? If the plug is removed, it could have unsuitable equipment plugged in? (Even if labelled as 5A only and located in a locked box in the garage, etc.)
2. Do plug-in timers just switch the L (SP) or both L & N (DP). If SP, can the N wires on both sides of the plug-in timer (ie, to the 13A socket and from the 13A plug) be connected in an adjacent 4T junction box? This would then be wired to a 3C+E cable, with permanent L, timer-switched L and N back to a 6T junction box next to the ceiling fan to pick-up the switched L from the bathroom light switch, and on to a 3T fan isolator switch then fan. Even if DP, could the N's still be connected on both sides?
3. Are fans classed as induction loads? Does this have an impact on what timers can be used?
It's not as pretty a solution as a fixed timer, but are there any reasons that this shouldn't work?
Not sure that I've managed to explain it all too well!
