EE isn’t my field, I’ve studied what I need to know to be a hobbyist and build rudimentary scientific instruments, so I’m happy to learn something I didn’t previously know about it, but pure water isn’t conductive and bath water isn’t much better. I’ve had to do conductivity testing (albeit with low amps and relatively high frequency) with soapy water mixes, which aside from that fact being frequently taught, is how I get my sense of its typical resistance. So-called suicide showers (Google has a lot of worthy hits), which I will grant you are a terrifying invention, don’t automatically kill people on every use despite being particularly irresponsibly connected to mains voltage. They do kill people, but not on every use. So while I wouldn’t ever, ever try or recommend people sit in the bathwater with an extension cord dangling into it, it’s not an immediate given that you will die just by touching any water anywhere in the tub.
See, the Internet’s favorite electrical daredevil, and self-confessed professional dumbass:
This is why I’m asking about the configuration…, it’s not that I doubt that electricity and bathtubs are a bad idea, but more me trying to understand the likeliest way this incident transpired for him to be electrocuted.
Most of the world uses 220/240V mains. 220/240 has many advantages including being much cheaper to wire because you can use thinner copper (but you need better isolation).
110/120V will kill you just as easily as 220/240V if it takes the right path through your body.
Is it cold in there Mr President? We’d like to give you this electric radiant heater to keep you warm. Just balance it on the edge of the bath, it should be OK.
Hence the extension cord. When I lived in the UK I had an extension cord more-or-less permanently threaded into the bathroom, though it was quite far from the bath. Because it was mainly on the floor, and in bathrooms floors get wet, it would have been safer to have a socket in the wall.
Technically US electrical codes are not national, but most areas have adopted some version of the (somewhat misleadingly named) National Electrical Code at this point. For example, my jurisdiction is currently enforcing the 2015 NEC (and until recently was enforcing the 2008 NEC with local amendations) for new construction.
The NEC has added additional ground fault circuit protection in every edition since the early 1970s. In the current edition all commercial kitchen outlets, regardless of location, must be GFCIs both in new construction and whenever an outlet is replaced or added in existing construction, and dishwashers in homes require GFCIs as well. But in prior editions, which are still the law in many states and cities, GFCIs were only required within a certain distance of water taps, and/or only in certain rooms such as bathrooms.
Today I put GFCI outlets in bathrooms and GFCI breakers in all kitchen circuits other than ceiling lighting circuits, and I run dedicated lines to outlets for microwaves, refrigerators, laundry equipment and HVAC locations. That exceeds the requirements in my area without vastly increasing cost in exchange for tiny increases in safety.
Note, in the USA, if you drop a three-wire extension cord in the bathtub, It seems to me you should get at most a very minor shock, even without a GFCI or other modern protection. The fuse or circuit breaker should blow before you take any damage, unless for some bizarre reason there is a discontinuity or very great resistance on both the neutral and safety ground wires. We’re only 120 volts here, not 240 like the UK, so a human body in water isn’t going to permit passage of a lot of current when there’s a closer path of less resistance. That being said, don’t try this at home!
Death by electrocution comes about from combinations of burns, fibrillation, and neurological damage; with fibrillation being the most common and biggest factor. Depending on the circumstances, you don’t need much current to cause fibrillation, but from external electrocution it’s generally said to be about 30mA across the heart will kill you. Skin resistance can vary wildly, but when wet and in a bath (which will have nice salty water from both the minerals in tap water and the salt from your skin) skin will have a pretty low resistance, as low as 2kΩ or lower (depending on skin, mineral contents of water, if a mouse farted in the neighbors’ house, etc). 60V is enough to give you a fatal shock there.
I was just going to say - he must have had some seriously old and/or seriously dodgy wiring. I wouldn’t want to test it, but RCD ‘fuses’ in the fusebox are standard now.
Isn’t that the easiest possible kind of defense, though? Not least because it’s apparently true, but also because it doesn’t require a jury (or a non-technically-inclined judge) to understand some intricate bit of electrical wizardry that Apple put in its charger. Just “it wasn’t our thing because it was this other thing, and everyone knows this other thing isn’t remotely safe to put in water when it’s plugged in.”
When I lived in the UK I had an extension cord more-or-less permanently threaded into the bathroom
Houses in the US often have wall sockets in the bathroom (protected by a GFCI breaker), and ours gets a lot of use, with several electric dental appliances, hair dryers, and a wall-mounted stereo system. I also have a 240 line in my kitchen next to a very wet appliance (a commercial espresso machine plugged into it), on the other side of which is the kitchen sink.
My bathroom in the UK had no built-in lighting, so I used the extension cord to plug in a lamp which stood on the washing machine (which was hard-wired to the wall) and occasionally a radio. This was a good 10 feet from the tub. I survived my years there OK, even despite that one bank holiday I spent lounging in the tub watching 3-4 James Bond movies on the telly. (Me, I was more afraid of the electric shower I had installed.)
I understand that water and electricity do not mix, but the the point of the UK code is to protect the stupid, which in fact makes it more dangerous for people who have legitimate reasons to use power in the bathroom.
Same here in Canada - also, switches (and I assume outlets as well) cannot be within arm’s reach of the tub or shower, forcing you to step out of the water zone to touch it.
