Electrocution via USB charger

deandean

I would have thought a 'consultant forensic engineer' would have at least done tests to see if he could recreate the fault, so he could report to the coroner with more supporting information.

However the coroner's court is not the same as the circuit court / high court.

I always remember the following case (unrelated) where, reading between the lines, it was pretty obvious to me what was going on that led to the guy being shot; however the coroner's court wasn't the place to spell it out.

https://m.sundayworld.com/crime/courts/mayo-pensioner-shot-friend-after-mistaking-him-for-an-intruder-inquest-hears/40832722.html

Windowsnut

My condolences to the family on the loss of their Mum, Anne-Marie was a lovely person, what a horrible tragedy.

Jakey Rolling

https://www.boards.ie/discussion/comment/123868042#Comment_123868042

That's correct, water conducts, but is a relatively poor conductor.

That's why any current will flow preferentially through the human body, with its juicy concentration of salts and ions.

This unfortunately often results in muscle spasms, nerve damage and arresting of the heart.

Would obviously need at least mains voltage to push enough current, say 100mA+ though

kirving

https://www.boards.ie/discussion/comment/123868795#Comment_123868795

The AC charger side of the charger is supposed to be totally isolated from the DC side though.

I'm thinking now that maybe the 0V side of the DC supply is actually connected to the 220V earth, and I shorted the 20V through that path. I'll actually take the charger apart this weekend and see.

I've got AC and DC shocks before (work in electronics), and this firmly felt more like DC, as there was no tingling/vibrating feeling.

10-10-20

https://www.boards.ie/discussion/comment/123874866#Comment_123874866

Id be surprised if it even has a metal ground pin on the mains plug.

Any of the floating PSU controllers have V reference built in so that they dont need to expose the user to ground.

Cordell

https://www.boards.ie/discussion/comment/123874866#Comment_123874866

Very unlikely to get a painful shock from 20V.

If it felt like DC maybe it was DC that you got through water ingress, a modern power supply will be DC to DC switched mode, and 230V AC rectified is over 300V DC.

Markus Antonius

https://www.boards.ie/discussion/comment/123866964#Comment_123866964

Everything comes from China these days, even the OEM stuff.

https://www.boards.ie/discussion/comment/123867052#Comment_123867052

Exactly, if water was such a good conductor, the current would have no reason to pass through the body/heart as the resistance of the body would have been relatively high. The water definitely compromised the skin's resistance combined with some fatal amp draw through the wire. How it was grounded is a mystery.

ImTiredOfItAll

Dr Okkers explained that the electric charge that flowed through the victim’s body would have interfered with her normal heart rhythm.

I can agree with this. I go Afib & a Cardioversion (200 joules) resets my rythem

John.G

I believe current flows as low as 20mA can cause even death in some cases so why the implication that mains voltage was the culprit in this tragic incident, if the immersed body resistance is , as I've read, can be as low as 500 to 1000 ohms, then even 20V will cause 20 to 40mA to flow.

Escapees

https://www.boards.ie/discussion/comment/123877051#Comment_123877051

"Can cause death in some cases" in theory but extremely unlikely.

Hotblack Desiato

https://www.boards.ie/discussion/comment/123866807#Comment_123866807

Dublin has soft water - at least the parts supplied from Wicklow do, which is most of it

But any source of water (apart from distilled or deionized) will have enough dissolved ions to make it a good conductor.

Yes, unfortunately, she needed to touch the tap to provide a path to earth. Baths are usually plastic and the drain trap is usually plastic also

Hotblack Desiato

https://www.boards.ie/discussion/comment/123866879#Comment_123866879

Maybe kids would learn more practical stuff like this if they didn't have to do half an hour of f'kin religion every day.

Hotblack Desiato

https://www.boards.ie/discussion/comment/123868837#Comment_123868837

Another poster mentioned reading a book in the bath.

For all we know, she could have been reading a book on her phone… would that make it OK? or is it 'addiction' because it has a screen instead of paper?

https://www.boards.ie/discussion/comment/123879465#Comment_123879465

Bit of a stretch.

We learned a lot more religion back in the day and still learned that electricity and the bathroom don't go well together.

But please do continue to try and work your anti religious rants into every possible thread and topic.

Former Former Former

https://www.boards.ie/discussion/comment/123879447#Comment_123879447

Dublin has soft water 

Tell that to all the kettles I've had to throw out over the years. Per the Irish Water website, the water in Santry (where this lady died) is hard.

Markus Antonius

https://www.boards.ie/discussion/comment/123881880#Comment_123881880

Thought you were going to say "Tell that to all the kettles I've had thrown in my bath" 😲

Antenna

https://www.boards.ie/discussion/comment/123867773#Comment_123867773

If all the pipe work in a bathroom is Qualpex/plastic rather than copper pipes, possibility of death is significantly reduced for most of these situations/accidents. It is also the case that bonding of pipes is a non-issue (something that could also get inadvertently damaged at some point) as they are non-conductive. The copper pipes provide practically a zero ohm path back to earth/neutral, as opposed to a very high resistance for tap water in a plastic pipe . See the youtube link below:

www.youtube.com/watch?v=MF9DCNkaE8I

Cordell

https://www.boards.ie/discussion/comment/123886580#Comment_123886580

I don't think this is a good approach - accept the possibility of having live objects in the house and relying on the fact that there won't be a path to ground.

It's better to ground all metal pipework and have all circuits protected by RCDs.