Xpelair 12v humidistat fan

[AdamSmith86]

Hello all,

I am looking to install an xpelair 12v fan in a bathroom with a humidity sensor (model no. 92970AW). I can't quite work out from the instruction manual whether the humidity sensor is in the fan itself or in the transformer. due to the size of the bathroom and the position of the bath it is necessary to mount the transformer outside the bathroom where a transformer mounted humidity sensor won't be of much use! So if anyone has installed one of these before I would grateful if you could let me know where the sensor resides.

Also on the subject, I am providing a dedicated circuit protected by RCD for the fan which I'll run to a 3a fused spur outside the bathroom. Is an isolator required in this case? I only ask as the tenants aren't the type you'll see polishing their doorstep and in my experience of working in less than savoury households, the fan iso's are more often than not switched off. Would an unswitched fused spur be satisfactory?

Regards

 

[AdamSmith86]

Or of course no FCU at all if the manufacturer does not specify one?

 

[Richard Burns]

The humidity sensor is mounted in the fan, there will be a small grille on the fan behind which is the sensor.
Most fan instructions require a DP isolator with minimum 5mm opening gap, this function would be provided by the RCD. Therefore a fused spur would be acceptable.
The other common recommendation is a triple pole isolator so that the fan can be worked on safely, however this function can also be covered by the RCD.
Some fan manufacturers do not require a local 3A (or 1A) fuse, I cannot remember for xpelair, I think they say you can use a lighting circuit, so so long as the MCB is 6A then you would be OK, but do check the instructions.

 

[AdamSmith86]

Great, thanks Richard.

 

[Octopus]

Are you sure you want to complicate matters using a 12v unit?

 

[AdamSmith86]

Yes I do.

 

[Octopus]

Why ???

 

[westward10]

It will work from a car battery in a power cut, obviously.

 

[darksideby182]

Dont worry re read it

 

[Rpa07]

Uh?!

 

[Midwest]

Dunno, I'm more inclined to fit extra low voltage extractor fan above shower head (including bath with additional shower head) rather than low voltage regardless of zones etc, but I'm willing to be convinced otherwise?

 

[westward10]

Dunno, I'm more inclined to fit extra low voltage extractor fan above shower head (including bath with additional shower head) rather than low voltage regardless of zones etc, but I'm willing to be convinced otherwise?

Why is this.

 

[Dave OCD]

Surely a mains voltage fan is only suited to Zone 2 at best and the OP wants to mount his fan in Zone 1 ?

 

[Richard Burns]

Surely a mains voltage fan is only suited to Zone 2 at best and the OP wants to mount his fan in Zone 1 ?

An IPX4 fan at 230V can be used in zone 1, it is one of the list of 230V items that can be be installed as fixed permanently connected equipment.

 

[Des 56]

Surely a mains voltage fan is only suited to Zone 2 at best and the OP wants to mount his fan in Zone 1 ?

What makes you state this Dave,is it belief that they are not permitted or personal preference?

Edit
Bit late with the question for you Dave, Richard has let the cat out of the bag

 

[Andy78]

I happily fit 230V fans in zone 1 where it is asked for or there is no option, usually to the protest and confusion of plumbers who know my job better than me.

If 230V was desired to be avoided, I would sooner fit a 230V inline fan in the roof void where possible rather than fit ELV.

 

[Dave OCD]

An IPX4 fan at 230V can be used in zone 1, it is one of the list of 230V items that can be be installed as fixed permanently connected equipment.

Sorry Richard [and Des] , I worded my post badly. I'm aware that the regs permit this but don't like putting a mains voltage fan directly above a bath or shower. Probably a bit silly on my part when you think of the mains voltage [and high current drawn] in an electric shower.

 

[AdamSmith86]

I am going for a 12v fan as the tenants don't strike me as the type of people who have much of a sense of self preservation... They probably have cash4claims on speed dial so don't fancy leaving 240v at arms reach for them. They have previously taken a ladle or other large kitchen utensil to smash the smoke alarms off the ceiling. Imagine doing that when they are all lathered up and super conductive!

 

[Midwest]

Sorry Richard [and Des] , I worded my post badly. I'm aware that the regs permit this but don't like putting a mains voltage fan directly above a bath or shower. Probably a bit silly on my part when you think of the mains voltage [and high current drawn] in an electric shower.

Concur with Dave, no rational reason.

My irrational morbid fear isn't helped any by manufacturers statements;

- Vent-Axia still recommends that any fans installed within Zones 1 and 2 should be SELV (Safety Extra Low Voltage

- Xpelair LV100 12V Safety Extra Low Voltage (SELV) fans offer complete peace of mind as they are specifically designed to be
installed directly in or over the splash area zone 1 in complete safety

- Manrose range of 12 volt S.E.L.V. (Safety Extra Low Voltage) fans are specifically designed for the safe ventilation of toilets, bathrooms and shower rooms and can be fitted within the splash area with absolutely no risk of
electric shock.

All (I think) Shower Light fans are selv?

However, I think it's time I manned up, and faced these nonsensical fears, put them behind me and start installing IPX4 fans in zones 1 & 2 as recommended by 701.512.2

 

[Dave OCD]

No go with what you're comfortable with Midwest, not all 230v fans are rated IPX4 and there's nothing wrong with improving on the minimum requirements stated in BS7671.
It's fine to fit a mains incoming LED downlighter above a shower though, I often do but make sure it's 1P65 and fed via an RCD.