
Man dies charging iPhone while in the bath - BrailleHunting
http://www.bbc.com/news/uk-39307418
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BrailleHunting
TL;DR: spend the $19 to buy a real, big brand USB charger because they have
more to lose than grey market no brand.

Tragic. Probably cheap USB without mains isolation or maybe enough water
dripped down length of cable and socket to create a circuit, because USB is
supposed to be 5V DC.

Watch these USB charger teardown horror-shows to further understand why it's
rational to pay for proper, authentic CE+UL, high-low isolation and quality
components (ie insulated tape in transformers):

[https://youtu.be/3Hdn0MuCK_0](https://youtu.be/3Hdn0MuCK_0)

[https://youtu.be/uRe9w5PKmsE](https://youtu.be/uRe9w5PKmsE)

[https://youtu.be/bNoGCdX1IdQ](https://youtu.be/bNoGCdX1IdQ)

[https://youtu.be/bmtW_oA1fRo](https://youtu.be/bmtW_oA1fRo)

[https://youtu.be/PKl6UJ57-2U](https://youtu.be/PKl6UJ57-2U)

[https://youtu.be/Ureg6RQVYS0](https://youtu.be/Ureg6RQVYS0)

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hilbert42
Hell incidents like this make me mad, because the risks of electric shock can
be minimized even for stupid idiots who believe water and power mains can
safely coexist.

If these so-called double insulated two-wire appliances [sans earth
connection] such as power packs, various light fittings, etc. etc. were
actually fitted with the third earth wire (and appropriately equipped to take
it) then the likelihood of electrocution in the circumstances described in the
article probably would not have happened.

In most of these two-wire devices the power input is essentially physically
symmetrical. If water gets on the active (hot side) rather then the neutral
then it's likely to leak by any means to ground (moreover there's no guarantee
that active and neutral are correct way around even if so marked (I've seen
power sockets active and neutral wired incorrectly quite often but never the
earth!). If you are in the way, as they say one flash and you're ash.

Note: it only takes about ~70mA across the chest (i.e.: from one arm to the
other) to kill you and that ain't much.

Surrounding the inside of the device with a conductive earth shield that's
properly connected to the mains earth via the third earth wire will help
because the physically closest point to ground is now the earthed bits.

When water gets inside such an appliance with only a little gap between the
active and earth then then it's sufficiently conductive to blow fuses at
240VAC or even the US's 110VAC.

I've examined iPhone type chargers whether Apple's own or third-party ones and
frankly they horrify me--all of them! There is precious little physical space
between the the hot primary side of the switch mode power supply and the
secondary and it doesn't take much water to close the circuit. Moreover, the
isolation insulation within these power supplies (the transformers, board
insulation etc. is pathetically minimal).

Remember, power systems around the world come with a third earth wire for a
very good reason. Power authorities wouldn't go to expense of putting all that
extra wiring in buildings, power cables etc. just for nothing. That lesson was
learned well over a century ago.

Two-wire 'double-insulated' appliances started to appear about 30/40 years
ago. Before that (except in the days of power engineering antiquity 90+ years
ago), two-wire circuits were only allowed for certain lights/lightning
assemblies.

Oh, BTW, this guy wasn't in a thrived-world country but in the UK. So why
wasn't the building he was in have earth leakage breakers in on the
switchboard?

Now I need some information that has troubled me for years.

How did these damned dangerous two-wire 'double-insulated' circuits/appliances
get approved in the first place? And why did approval authorities allow them
to be approved? What was the rationale? Pressure from manufacturers perhaps?

Yes, I've seen the ins and outs of the approval rules and I agree they're
perfectly fine when dry--no question about that. But life isn't like that as
this poor guy found out. Regulations simply have to assume that water, mains
power and idiocy--or even just unfortunate happenstance will all converge at
some point.

Finally, I know what it's like to end up nearly dead. Years ago, I got a belt
across the chest from an 850VAC transformer rated at 250mA. I was knocked
completely across the room 15ft or so and I couldn't move for about 40 minutes
. The only reason I survived was that muscle contraction disconnected me from
circuit in time. Had my hand been wrapped around the device it would have
contracted and I'd have been history.

It wasn't the only shock I've had but it was by far the worst (I was 14 years
old at the time and just damn stupid and careless).

