Replacing 12v bathroom fan with 240v one.

[no fit state]

Hi. I'm currently renovating my bathroom and I want to replace the extractor fan with something a bit more modern with a brushed stainless steel look finish.

The current setup is a 12v with a transformer outside the bathroom above the door. Despite spending hours on the net and visiting 2 electrical suppliers I've not been able to find any 12v fans in the finish I'm looking for. There are plenty of 240v ones though.

So my question is, if I fit a ipx4 rated 240v fan in zone 1. Which in my case is at the far end of the bath away from the shower and taps and 1.9m from floor level, can I just bypass the transformer in the box by way of directly linking the cables to send 240v straight to the fan?

My fuse box was fitted in 2011 and has an rcd for the lighting circuit which operates the fan.

Cheers.

 

[PrenticeBoyofDerry]

Yes a suitable 230V/240V extractor fan can be installed in zone 1. The fan must be IP rated at at least IPX4 and be suitable for the environment, read the MI of product prior to purchase. If the fan is exposed to water jets then the degree of protection must increase to at least IPX5.
The transformer can be omitted, but I would check that you have the correct number of cables at the fan top achieve your objective safely.

 

[Taylortwocities]

ICON fan, a bit pricey maybe, but the bees knees
One of these
Airflow 12 volt iCON15 ECO Low Profile Extractor Fan 78.84 m3/h
and one of these
Satin Silver Facia for iCON15
and a timer module if you need one
iCON 12v Adjustable Timer Module + Delay Start

 

[no fit state]

Yes a suitable 230V/240V extractor fan can be installed in zone 1. The fan must be IP rated at at least IPX4 and be suitable for the environment, read the MI of product prior to purchase. If the fan is exposed to water jets then the degree of protection must increase to at least IPX5.
The transformer can be omitted, but I would check that you have the correct number of cables at the fan top achieve your objective safely.

Thanks for the reply! I have a neutral and switched live at the fan end so will only be looking at basic fans with a 2 cable connection and at least ipx4.

 

[JohnW2]

I have a neutral and switched live at the fan end so will only be looking at basic fans with a 2 cable connection and at least ipx4.

... The current setup is a 12v with a transformer outside the bathroom above the door. ...

If I understand correctly, with the current setup you will have a 2-core cable carrying 12V from the (remote) transformer to the fan, not a ('mains') neutral and switched live. That cable may or may not be suitable for carrying 230V/240V to the fan. What sort of cable is it?

Kind Regards, John

 

[Taylortwocities]

And you need to check if the existing system is a timer set up. The timer will be in/at the transformer, with only two wires going from the transformer to the fan.

 

[JohnW2]

And you need to check if the existing system is a timer set up. The timer will be in/at the transformer, with only two wires going from the transformer to the fan.

Indeed, but the OP seems to have already accepted that the fact that there is only 2-core cable going to the fan means than he can only have a 'basic' (non-timer) one.

However, as I've said, it's far from a foregone conclusion that the present cable between transformer (outside of the bathroom) and fan would be suitable for 230V - if that cable is not easily be replaced, that could possibly become the biggest problem.

Kind Regards, John

 

[Taylortwocities]

I am aware of that. If the existing system is a timer, and if the environment needs a timer, then he may need to find another 12v fan.

 

[JohnW2]

I am aware of that. If the existing system is a timer, and if the environment needs a timer, then he may need to find another 12v fan.

All true, but the OP seems to have accepted that, by his reasoning (only 2-core cable) he would have to accept a non-timer fan, which I took to mean that he feels that he does not "need a timer". However, maybe that's not correct ...

... so will only be looking at basic fans with a 2 cable connection ....

Kind Regards, John

 

[no fit state]

Thanks for all your replies. There is no timer on the old fan, just a standard on off by the light switch fan and definitely no timer in the transformer box either.

The core size of the cable at the fan end I’ve just measured at 1.4mm. So I think I’m good to go with a 240v fan by just connecting the cable that was going into the transformer with the one that was coming out it and bypassing the transformer?

 

[JohnW2]

Thanks for all your replies. There is no timer on the old fan, just a standard on off by the light switch fan and definitely no timer in the transformer box either.

Thanks for clarifying.

The core size of the cable at the fan end I’ve just measured at 1.4mm. So I think I’m good to go with a 240v fan by just connecting the cable that was going into the transformer with the one that was coming out it and bypassing the transformer?

The size of the conductor would not be an issue - apart from anything else, a 240V fan will take only about a twentieth of the current that a 12V one did. The issue is whether your current cable (carrying 12V) is adequately insulated/sheathed to be used with 230V/240V - which might well not be the case, at least in terms of 'rating'. As I asked, what sort of cable is it (what does it look like?)? A photo might help.

Kind Regards, John

 

[Taylortwocities]

Conductor sizes are measured by cross sectional area. So I don’t know how you measured it, unless you have a micrometer.

There is a rough guide to cable sizes in the WIKI
https://www.diynot.com/wiki/Electrics:flatpvccables

 

[no fit state]

Thanks for clarifying.
The size of the conductor would not be an issue - apart from anything else, a 240V fan will take only about a twentieth of the current that a 12V one did. The issue is whether your current cable (carrying 12V) is adequately insulated/sheathed to be used with 230V/240V - which might well not be the case, at least in terms of 'rating'. As I asked, what sort of cable is it (what does it look like?)? A photo might help.

Kind Regards, John

Here’s a photo of the cable.

 

[Taylortwocities]

Looks like 1mm² twin & earth.
Fine for a 240v fan.

 

[no fit state]

Conductor sizes are measured by cross sectional area. So I don’t know how you measured it, unless you have a micrometer.

There is a rough guide to cable sizes in the WIKI
https://www.diynot.com/wiki/Electrics:flatpvccables

I’m an engineer by trade, measuring equipment I have a lot of! So it was measured with a digital vernier. (The unused earth was 1mm dia)