• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Safety for electronics in a bathroom?

Status
Not open for further replies.
I have a hobby project with a fan controlled by an Arduino that extracts humid air when this is detected.

Is this considered safe in general, or at all? I'm using a typical laptop PSU for power, this one: https://www.amazon.com/UpBright®-Adapter-FSP050-DBCD1-Supply-Charger/dp/B00AI1APJC

I imagine it is possible that it could get humid enough for the pins on the Arduino to become bridged, but is 12 volts enough with fresh water to be any problem? There is also the possibility that something inside the fan might short (I don't know how, I'm just speculating), but again this is also only 12 volts (the fan draws 2 A), and this is fresh water.

If this is crazy, please tell me and I won't use it, if not then I'd also like to hear it so I can feel safer.
 

Pommie

Well-Known Member
Most Helpful Member
You don't state where you're from so it's kinda difficult to advise. In the UK, above most bathrooms you'll find 12V transformers for the downlights. I'd go for something similar as they are designed for this purpose. If you're talking about something in the bathroom then it's probably not a good idea.

Mike.
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
I don't think it's designed for that application. Many electronics parts are rated for an RH in a non-condensing environment.

the enclosure is going to matter. Something like this http://www.trcelectronics.com/Cosel/din-rail-power-supply-kh.shtml rated as Class 2 would be appropriate in the US in a suitable enclosure. Class 2 basically means limited to 100 W and you don't have to run the low voltage in conduit.

There are various IP ratings for enclosures. https://en.wikipedia.org/wiki/IP_Code
 

spec

Well-Known Member
Most Helpful Member
You don't state where you're from so it's kinda difficult to advise. In the UK, above most bathrooms you'll find 12V transformers for the downlights. I'd go for something similar as they are designed for this purpose. If you're talking about something in the bathroom then it's probably not a good idea.

Mike.
The OP is from Norway, as stated on his profile. Norway has comprehensive and strict standards about safety like most developed countries.

This means, in general, that any mains powered circuits must be double insulated, or whatever the term is in the standards, and be suitable for a humid environment. I not sure about this, but I think any voltages in a humid environment should be no more than around 30V RMS or 5oV DC. Also all conductive items, radiators, showers, taps etc must be earth bonded.

spec
 
The OP is from Norway, as stated on his profile. Norway has comprehensive and strict standards about safety like most developed countries.

This means, in general, that any mains powered circuits must be double insulated, or whatever the term is in the standards, and be suitable for a humid environment. I not sure about this, but I think any voltages in a humid environment should be no more than around 30V RMS or 5oV DC. Also all conductive items, radiators, showers, taps etc must be earth bonded.

spec
So I should get a double insulated power supply?
 

spec

Well-Known Member
Most Helpful Member
So I should get a double insulated power supply?
You need a power supply that conforms to your countries electrical safety standards. This is not a cop out but you need to read the standards to get the full story before you attempt any wiring in a bath room. Your local library may have a book to help, or the internet should give you the required information. In legal terms you are simply not allowed to do any domestic wiring. It must be done by a qualified electrician who has to supply a safety certificate for the work done. I am using the situation in the UK, but I would think it is the same in Norway.

spec
 
You need a power supply that conforms to your countries electrical safety standards. This is not a cop out but you need to read the standards to get the full story before you attempt any wiring in a bath room. Your local library may have a book to help, or the internet should give you the required information. In legal terms you are simply not allowed to do any domestic wiring. It must be done by a qualified electrician who has to supply a safety certificate for the work done. I am using the situation in the UK, but I would think it is the same in Norway.

spec
I understand but isn't there a difference between installing 220 volts wiring and sockets, and just plugging in a standard power adapter into an already existing socket? I'm assuming it is okay to build your own hobbyist fan project and connect it to a socket? The only problem is placing the fan in the bathroom?

I know this will not conclude with any definitive answer, so this is just for the rough and intuitive understanding at this point. Maybe I've missed something.
 

spec

Well-Known Member
Most Helpful Member
I understand but isn't there a difference between installing 220 volts wiring and sockets, and just plugging in a standard power adapter into an already existing socket? I'm assuming it is okay to build your own hobbyist fan project and connect it to a socket? The only problem is placing the fan in the bathroom?

I know this will not conclude with any definitive answer, so this is just for the rough and intuitive understanding at this point. Maybe I've missed something.
Its the fact that the fan is a fixture and is in the bathroom. If however the fan is certified for use in a bathroom ceiling and correct ducting and easrth is fitted it would be safe. But all the same, strictly speaking without a safety certificate you would be contravening the rules. Sorry

spec
 

Pommie

Well-Known Member
Most Helpful Member
It's a long time since I did any electrical work in the UK but I thought less than 50V was unregulated in homes (seem to remember it was lower for stables!). And I would think you can do anything you want at 12V, or has it changed that much?

Mike.
 

spec

Well-Known Member
Most Helpful Member
It's a long time since I did any electrical work in the UK but I thought less than 50V was unregulated in homes (seem to remember it was lower for stables!). And I would think you can do anything you want at 12V, or has it changed that much?

Mike.
Things have changed an awful lot recently- basically only certified electricians can do any electrical installations. 12V from a battery would probably be OK but if the 12V comes from the mains there is a danger that the mains can get on to the 12V, hence the the double insulation, or whatever the term is now. The idea being that if the mains connected device fails it does not put mains on to the 12V.

spec
 

Les Jones

Well-Known Member
Most Helpful Member
Hi halleffector,
This is not realy related to your question. Using an Arduino to control a fan seems a bit overkill. You could use a DHT22 temperature and humidity sensor with an 8 pin microcontroller (PIC or Atmel ATtiny). I have built a unit using a PIC12F1822 which outputs the temperature and humidity as an ASCII text string. This is the schematic.

DHT22 reader.png
The code could easily be modified to switch an output pin on and of when the humidity reaches the set level. The source code is on my website. (At the bottom of the page.)
 

dr pepper

Well-Known Member
Most Helpful Member
Cant you put the fan outside the room, or in the eaves of the building and route a flexi duct back to a grille in the bathroom, this is a common method for mains powered extracts.
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
In my case (US), the fan/light was purchased as a single unit, no control. 120 VAC operated. Small shaded pole motor located in the fan.

I put a delay on break timer in a J-box in the attic which now needs to be replaced. The control method was to basically turn on the 120 VAC fan for 20 minutes after you turn the fan switch off. It did work well for about 40 years.

A single gang dual-switch controls the exhaust fan and light with a delay on break timer for the fan. The IR heater was controlled with a 20 minute mechanical timer.

The attic does put the controls at an elevated temperature. Using a Delay on Break was effective rather than using a humidity controller.

Currently the fan makes too much noise and does not turn off reliably. I suspect due tot he solid state switch and the timer itself,

Missing items are a decent check valve.

There may be something in this post you can use.
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top