USB charger outlet in Bathroom Zone2

Wow. So much great information here guys.

If I've understood  correctly 

1. It is possible to have a USB in Zone 2.

2. It must be IPX4 rated (im not sure how to protect the pins)

3. The output must be SELV 

4. The converter must be outside zone 2 and hard wired.

5. It must be on a 30rcd 

6. It must have limited energy ie 20va (3.1A/ 5v) {base on shaver socket energy}

From the safety risk, these may less then what is allowed, but due to the potential of a submerged body in fresh water and the higher PD voltages and current that those pose a risk.

At present, im not sure if the idea is to use the USB in a bath but it is a foreseeable risk when the socket is so close to the bath. 

It is a shame that 12v or even 24v  wouldn't be used but reading between the lines, thes voltages could increase risks.

I presume there are no restrictions  once outside zone 2 but  not the full 3m away from zone 1?

Thanks for all the comments

Peter69 said:

I presume there are no restrictions  once outside zone 2 but  not the full 3m away from zone 1?

It's 2.5m these days rather than 3m, but yes the limitation is on all sockets except SELV or isolated shaver types. 701 specific requirements for the room/location outside zone would still potentially apply (e.g. connected to supplementary bonding system if there is one, if the output was PELV for instance, RCD additional protection etc.)

   - Andy.

Peter69 said:

I presume there are no restrictions  once outside zone 2

Correct, although as in the electric shock case I pointed to, people will use long leads if they are hell-bent on charging in the bath ... although assuming there are mains socket-outlets in the bathroom, you wouldn't be making things any more dangerous.

For the avoidance of doubt, according to the electronic product manufacturers, using devices on charge in the bath is misuse ... I'm not saying manufacturers are doing anything wrong, nor am I saying installers are in the wrong for putting socket-outlets or charging equipment in compliant places that might make use of USB charging for devices in a bath more accessible.

The problem I have is, at what point does it become 'foreseeable misuse' from the perspective of a court ? What, if anything, can we do in our standards and practices to prevent that misuse? 

gkenyon said:

although as in the electric shock case I pointed to, people will use long leads if they are hell-bent on charging in the bath

If you bring an extension lead in from the landing, the door will not be locked (unless there is a gap beneath it). There is case-law concerning deaf people, fire alarms, and entitlement to personal independence payment which is based upon the notion of bathing privately.

That said, if you bathe in a bedroom, presumably privacy is not at the top of the agenda, particularly if you are Whatsapping at the same time.

gkenyon said:

The problem I have is, at what point does it become 'foreseeable misuse' from the perspective of a court ? What, if anything, can we do in our standards and practices to prevent that misuse?

Judges in the Appellate Courts seem to have taken a common sense approach based upon the facts. This thread is evidence that some people do take a 'phone (or iPad or WHY) into a bath whilst it is charging, so I am not sure that foreseeability is the issue.

I suspect it really is a matter of where the duty of care lies. Is it the manufacturer or supplier of the 'phone, the manufacturer or supplier of the extension lead, the electricity supplier, BSI, and so on?

My personal opinion is that a warning in the instructions discharges the duty of care.

Chris Pearson said:

My personal opinion is that a warning in the instructions discharges the duty of care.

I wouldn't disagree with that .. although there are ways in which changes have been sort of mandated in product standards; for example, the safety interlocking system that requires a start button to be pressed to restart a domestic tumble dryer to prevent the machine automatically restarting if a toddler gets in and the door shuts.

(Surely children ought to be supervised, though?)

This is why I would limit USB output to the fixed low voltage of 5v. I would be supplying to a contractor who is supplying to the prime contractor who is fitting it to hotels. Any warning would need to be added to the front plate in all languages (person in bath crossed through icon?).

But looking at the risk to all involved limiting voltage to 12v max, separated from earth with a max output in fault condition of 20va (as per shaver) limits the risk to life.

My research would suggest the risk even with bath salts and damaged skin to negligible although the USB probably wont charge many new devices. Therefore whats the point?

I have to be honest, I still cant see how a floating voltage between + & - so close together offers any risk given that pin to pin must sill be the shortest and lowest resistance path. I dont understand why the electrons would go the lone way round and even into the wet human body even at only 500ohms resistance that achieves enough to reach let go levels let alone death.

This is way below hospital limits

gkenyon said:

Surely children ought to be supervised, though?

Parents of young children need eyes in the back of their heads.

Doesn't help if a cat sneeks in - link. What a beauty!

Peter69 said:

I have to be honest, I still cant see how a floating voltage between + & - so close together offers any risk given that pin to pin must sill be the shortest and lowest resistance path. I dont understand why the electrons would go the lone way round and even into the wet human body even at only 500ohms resistance that achieves enough to reach let go levels let alone death.

Electricity in water doesn't behave in the way you'd expect.

There are people who have died from hairdryer, heated curling appliance, or shaver on charge falling into the bath they were in (not in the UK) ... you'd have thought the mains would take the short path between the L and N pins, but even if it did, the 'parallel path' through the body only needs to conduct a relatively small current for things to be fatal. These things do happen.

In the UK we've had a relatively good record with the prohibition on socket-outlets close to a bath that have been in place for a very long time. 

Peter69 said:

I would be supplying to a contractor who is supplying to the prime contractor who is fitting it to hotels. Any warning would need to be added to the front plate in all languages (person in bath crossed through icon?).

A good point.

Would this do?

Chris, over the last few years, particularly in the more modern and "Trendy" high class hotels the bathroom, shower room, wet room has no physical door between the bath/shower area and the bedroom itself, yes some internal partitions may offer a small level of privacy. But in those cases not even a door to pass a lead underneath!! its just one aperture where the door would normally be.

GTB

Chris, over the last few years, particularly in the more modern and "Trendy" high class hotels the bathroom, shower room, wet room has no physical door between the bath/shower area and the bedroom itself, yes some internal partitions may offer a small level of privacy. But in those cases not even a door to pass a lead underneath!! its just one aperture where the door would normally be.

GTB