This is a sombre topic: I was wondering if this story is possible(electrocution) - Page 1
Forum section: electronics / beginners

author: blissed
author_rank: Newbie
timestamp: December 05, 2021, 05:28:26 pm
content: So in this german articlehttps://www.spiegel.de/panorama/frankreich-verkabeltes-handy-faellt-in-badewanne-13-jaehrige-tot-a-56c24b50-f75d-4a1c-9336-6ca8bc46fe4cit basicly says a girl dropped her mobile phone in the bath while charging and she got electrocuted and died days later in a hospital.I"m an ex ee student and now computer science student.So I was wondering if thats the hole story.My first feeling was maybe the charger was in an extension cord and that assembly got dropped in the bath, in which case I understand the outcome - no futher questionsHowever I dont think you could seriously electrocute yourself with 5v 1a charger, but I didnt consider modern fast chargers.To my knowledge there are some mobile phone chargers with 65W or more.I just would like to know what would happen if you drop the output of usb c fast chargers in for example a bath?I would assume not a hole lot would happen aside from some water vaper, maybe im completly wrong but, because modern fast chargers proberly have pretty good protections. I would assume 230v mains would be much much worse

author: wraper
author_rank: Unknown
timestamp: December 05, 2021, 05:34:58 pm
content: If it was a counterfeit Chinese charger, there is nothing surprising about it. Usually they have barely any isolation from the mains voltage. And as there is basically no QC, they sometimes have a short between the mains and secondary side. Like solder bridge due to pad proximity or transformer defect.

author: wraper
author_rank: Unknown
timestamp: December 05, 2021, 05:38:08 pm
content: https://www.businessinsider.com/apple-fake-chargers-study-2016-12

author: blissed
author_rank: Newbie
timestamp: December 05, 2021, 05:42:36 pm
content: I thought about cheap chinese chargers, sadly the article doesnt mention any details. In case of those death chargers I also completly understand. But if we assume its a original charger or a properly engineered charger

author: IanB
author_rank: Super Contributor
timestamp: December 05, 2021, 05:52:33 pm
content: Quote from: blissed on December 05, 2021, 05:28:26 pmActually, simply dropping a mains extension cord in the bath is unlikely to electrocute you in and of itself, since there wouldn't immediately be much of a current path through your heart. The danger happens if, through panic or lack of awareness, you pick up the end of the cord with your hand. At that point there could be a current path down your arm and through your chest.What you should do if such an accident happens is bunch yourself up in a ball as far away from the extension cord as possible and call for help. Someone else can unplug the cord to remove the danger.Unfortunately, most people would not have enough knowledge to react this way.

author: themadhippy
author_rank: Super Contributor
timestamp: December 05, 2021, 05:57:56 pm
content: If you must use and charge your toys whilst in the bath at least have the sense to use the shaver socket

author: blissed
author_rank: Newbie
timestamp: December 05, 2021, 06:01:02 pm
content: So if I get you all right 230V ac is the actual risk and most likely exponation, not the 5v-20v dc

author: james_s
author_rank: Super Contributor
timestamp: December 05, 2021, 07:07:10 pm
content: Quote from: IanB on December 05, 2021, 05:52:33 pmSeems like the safest thing to do is simply stand up and step out of the tub. As long as you do not get too close to the end of the cord I don't think there is much risk, the most direct path for the current is going to be to the neutral and earth pins in the end of the cord. Seems like Mythbusters did an experiment that involved dropping a hair dryer into a bath and found similar results.The mobile phone electrocution is plausible though, a person holding a phone in their hand could end up having a very low impedance connection to metal on the phone which will not have a safety ground and part of their body could be in close proximity to or even touching grounded plumbing fixtures.

author: artag
author_rank: Super Contributor
timestamp: December 05, 2021, 07:16:35 pm
content: Quote from: james_s on December 05, 2021, 07:07:10 pmI agree.Most chargers will leak a little current. Some may leak quite a lot and you might feel a slight buzz if you touch the phone while connected. I have certainly encountered people who can feel what appears to be a vibration when they touch the metal cover of their Mac - so even good quality parts may show this. Poorer parts can be worse but still not cause obvious injury.But if your feet are very well grounded through the water and you pick up the phone with your hand, that current may be larger and will be passing through your heart.

author: james_s
author_rank: Super Contributor
timestamp: December 05, 2021, 07:49:01 pm
content: I'm actually kind of surprised that chargers are still not required to be earth grounded. I see no obvious issue with tying the negative output or at least the shell of the USB connector to earth ground. A desktop PC will have both tied to earth.

author: rstofer
author_rank: Super Contributor
timestamp: December 05, 2021, 09:01:48 pm
content: In the US, outlets in the bathroom are required to have a GFCI (Ground Fault Circuit Interrupter) device for this very reason. They have been a code requirement for 50 years. Of course, we have houses much older than 50 years and hopefully the homeowners have upgraded over the years but maybe not.

author: tooki
author_rank: Super Contributor
timestamp: December 05, 2021, 09:13:44 pm
content: Quote from: blissed on December 05, 2021, 06:01:02 pmNot just "likely", but "necessarily" so. 5-20V can only kill you if you apply it through broken skin on both sides of the circuit.

author: langwadt
author_rank: Super Contributor
timestamp: December 05, 2021, 09:28:18 pm
content: Quote from: rstofer on December 05, 2021, 09:01:48 pmhere everything even old installations must have RCDs, I suspect much of the rest of EU have similar rules

author: Gyro
author_rank: Super Contributor
timestamp: December 05, 2021, 09:30:50 pm
content: Quote from: blissed on December 05, 2021, 05:28:26 pmThis is sadly not the first report These cases do seem to occur from time to time. Here are some previous threads on exactly the same subject. Maybe you can see some similarities in circumstances by reading through them...https://www.eevblog.com/forum/beginners/why-some-people-died-in-their-bath-after-smartphone-dropped-into-water/https://www.eevblog.com/forum/dodgy-technology/cheap-usb-phone-chargers-are-potentially-dangerous/https://www.eevblog.com/forum/chat/hugo-14-electrocuted-in-his-bath-because-of-his-mobile-phone-!/https://www.eevblog.com/forum/chat/another-tragedy-cellphone-chargers-and-bathtubs-don_t-mix/https://www.eevblog.com/forum/chat/is-this-really-likely/https://www.eevblog.com/forum/chat/man-dies-charging-phone-in-the-bath/https://www.eevblog.com/forum/dodgy-technology/electrocution-via-earbuds!!-reports-of-death-from-multiple-sources/Edit: Yes there are quite a few!

author: IanB
author_rank: Super Contributor
timestamp: December 05, 2021, 09:32:31 pm
content: Quote from: james_s on December 05, 2021, 07:07:10 pmThis is true. However, there is a danger that if you jump up in a panic, then you could slip and fall.

author: themadhippy
author_rank: Super Contributor
timestamp: December 05, 2021, 09:51:56 pm
content: Quotein the uk no sockets within 3 meters of a bath or shower, rcd or not,the only exception is shaver sockets that have an isolation transformer and cant be closer than 600mm

author: amyk
author_rank: Super Contributor
timestamp: December 05, 2021, 10:39:34 pm
content: Quote from: blissed on December 05, 2021, 05:28:26 pmThis is the most suspicious part - electrocution is normally quick.I think the real lesson everyone needs to learn from stories like this is to not use mains-powered devices while you're in the bathtub. I remember seeing one a few years back where the person decided to use an extension cord...

author: BrokenYugo
author_rank: Super Contributor
timestamp: December 05, 2021, 11:26:17 pm
content: The transformers in the cheap unbranded chargers are often wound with zero attention to safety, typical to find cold side wires crossing hot side wires, so the only thing between the user and mains is two layers of cheap enamel.

author: james_s
author_rank: Super Contributor
timestamp: December 06, 2021, 12:28:33 am
content: Quote from: themadhippy on December 05, 2021, 09:51:56 pmAll that does is encourage someone to use an extension cord from whatever the nearest socket is. That was what happened in at least a couple of these cases I read about, someone trailed a wire in from another room to have their phone plugged in.I'm surprised things haven't been updated to allow a socket in the bathroom, the GFCI (RCD) outlets are much more sensitive than the whole house breakers and you can't run a hair dryer, curling iron, or other higher power appliance from one of those shaver sockets and the transformer would be lossy for plugging in something like an electric toothbrush charger.

author: DavidAlfa
author_rank: Super Contributor
timestamp: December 06, 2021, 10:41:49 am
content: Perhabs the usb cable was too short and the person used a mains extension cord, placing it close to the water?In any case, everyone in the planet knows that electricity+water is a nasty combination. Don't even try.Except this person, it seems. So that was Darwin doing its job, nothing to worry about.I smell a lot of bs here, but this could be a combination of old/crappy electric installation + chinesium charger.Humid zones (Talking about house places, control your dirty minds) have their own leakage detector (Again, talking about house places!), which use a more sensible rating.In UE, while the "main" breaker uses 30mA rating, bathrooms use it's own with 5mA rating. So it's extremely hard to die electrocuted.This didn't exist 30 years ago, so old installations might not be so lucky. I've even seen single-pole breakers opening the neutral instead the live! Yes, freaking dangerous!So there're a lot of possible factors here. But in the 99.9% of the cases, this is impossible.

author: Watth
author_rank: Frequent Contributor
timestamp: December 06, 2021, 11:18:14 am
content: I guess the charger was not properly isolated, so on of the USB leads was still at (or close enough to) the main's live potential.

author: rpiloverbd
author_rank: Regular Contributor
timestamp: December 06, 2021, 11:22:33 am
content: As water is a first class conductor, dropping a charger's chord into the water while connected to 220V is enough to cause electrocution. The charger in question here was connected to the phone. And the phone fell in water. So, death doesn't sound surprising to me here.

author: richard.cs
author_rank: Super Contributor
timestamp: December 06, 2021, 11:42:53 am
content: Quote from: james_s on December 06, 2021, 12:28:33 amA former colleague wired his bathroom to German standards (using the "equivalent standard of another European country" clause in the building regulations) so his wife could have a (Schuko) socket for her hairdryer. He later found that he was the first person to make use of that clause and the approval eventually rattled right up to the secretary of state.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: December 06, 2021, 11:57:31 am
content: I am not familiar with 240 V used in many countries. I am familiar with US voltages. I have worked in emergency rooms for over 10 years and do not recall seeing any electrocutions happen this way.The electricity has to go through you to ground, The ground here is the water and drain pipes. I suppose that is possible.I have seen electrocutions but they were all industrial accidents involving very high mains voltages, perhaps thousands of volts in unprotected circuits.So you would have to be holding one end of the wire and the electricity has to go through you to the ground. Possible that 240 could electrocute you. Now maybe someone has some sort of heart arrythmia that could be set off by a lesser charge.I also dont know much about the ground faults used in other countries.

author: tooki
author_rank: Super Contributor
timestamp: December 06, 2021, 05:01:49 pm
content: An unlikely, but theoretically possible scenario is that the phonewasin fact grounded, and that it was theplumbingthat was live. Especially with the growth of plastic pipes, especially when used as a retrofit during a repair, it’s possible to end up with building plumbing electrically floating. If an electrical fault elsewhere in the building comes in contact with the floating plumbing, you can end up with live plumbing. (This is why it’s a big no-no to use plumbing, like a radiator or water pipe, as a ground for an appliance on an ungrounded outlet! You could theoretically electrocute someone in a different apartment and not even know it!!)

author: james_s
author_rank: Super Contributor
timestamp: December 06, 2021, 05:57:26 pm
content: Quote from: Wallace Gasiewicz on December 06, 2021, 11:57:31 amPeople can and have been electrocuted by 120V, if you worked in an emergency room you probably didn't see many electrocutions as in most cases the person was dead before they hit the ground. An electrician was killed in an old building where a friend of mine worked about 10 years ago, I suspect it may have been a 277V lighting circuit but I don't know for sure, that's the highest voltage that was present in the building. The big difference between 240V in North America and 240V in other parts of the world is here both sides are 120V from ground, 240V between them while elsewhere it is a single ended 240V to ground.

author: Ice-Tea
author_rank: Super Contributor
timestamp: December 06, 2021, 06:00:54 pm
content: Quote from: rpiloverbd on December 06, 2021, 11:22:33 amIt really isn't.QuoteNot at all. No charger voltage is enough to electrocute you. Only the primary voltage. Which is isolated from the secundary. In fact, in order to avoid that a single point of failure can lead to lethal conditions,doubleisolation is required.In just about all of these cases, a crap aftermarket charger was at fault.Quote from: langwadt on December 05, 2021, 09:28:18 pmYup. But per example here the "main" RCD is 300mA. Dedicated bathroom RCD for 30mA or less may have been mandated only later. And 300mA is plenty to stop the old ticker.

author: Watth
author_rank: Frequent Contributor
timestamp: December 06, 2021, 06:25:41 pm
content: Quote from: Ice-Tea on December 06, 2021, 06:00:54 pmExcept if it's a cheapo charger?

author: Ice-Tea
author_rank: Super Contributor
timestamp: December 06, 2021, 06:29:26 pm
content: Quote from: Watth on December 06, 2021, 06:25:41 pmIf the cheapo charger is qualified, it *must* have double isolation. The Alibaba special though probably doesn't care.

author: Bud
author_rank: Super Contributor
timestamp: December 06, 2021, 06:50:46 pm
content: Quote from: Ice-Tea on December 06, 2021, 06:00:54 pmMay not be exactly isolated because many switching converters have a capacitor between the primary and secondary sides for EMC purpose. A leak may exist from the primary through that capacitor.

author: Ice-Tea
author_rank: Super Contributor
timestamp: December 06, 2021, 06:56:30 pm
content: And that capacitor is sized so the current it allows is well,wellbelow the lethal threshold (and it should be a safety cap, which is the equivalent to double isolation). But that cap is probably the reason why you might feel a bit of tingle with some metal surfaces.If I remember correctly, sometimes even a resistor is applied between prim and secundary but the same rules apply: no single point of failure and very low current/high impedance.

author: wraper
author_rank: Unknown
timestamp: December 06, 2021, 07:03:23 pm
content: Quote from: Mechatrommer on December 06, 2021, 06:56:45 pmApple chargers get bad, get broken, get lost, spare charger because owner wants to charge at multiple places without bringing the charger, whatever. Genuine decent quality electronics get broken and its not unusual. But they do not become unsafe, and if they occasionally do, then are recalled. Buying a new charger is not something unusual, and that's why there are so many counterfeits around. Their construction is so bad, it seems that occasional electrocution is intended by design. Making them 1000 times safer would cost zero.

author: Bud
author_rank: Super Contributor
timestamp: December 06, 2021, 08:22:40 pm
content: Quote from: Ice-Tea on December 06, 2021, 06:56:30 pmPlenty of constraints for chinese 'designers' to violate

author: BrokenYugo
author_rank: Super Contributor
timestamp: December 06, 2021, 09:27:05 pm
content: Quote from: Bud on December 06, 2021, 08:22:40 pmSeems the cheap ones use a generic dipped 1KV ceramic disc cap with no Y rating. That said the nightmares within the transformer are likely the biggest shock hazard.

author: ejeffrey
author_rank: Super Contributor
timestamp: December 06, 2021, 11:33:32 pm
content: Quote from: james_s on December 06, 2021, 12:28:33 amThat's why bathrooms in the US are actually required to have outlets. So someone doesn't run a cord from a non GFIC outlet in the hallway to power their hair dryer.

author: Microcheap
author_rank: Frequent Contributor
timestamp: December 06, 2021, 11:57:30 pm
content: This guy tests and disassemble various USB chargers on hisand given the horror shown, the story is not only possible but it makes me think that such accidents could be more common.In some chargers, the mains voltage on the primary of the transformer are insulated from the secondary only by the varnish on the wire.

author: m3vuv
author_rank: Super Contributor
timestamp: December 07, 2021, 12:20:50 pm
content: as far as i know water is non condutive,it only conducts when it isnt pure,ie has minerals and salts in it,im sure they test the purity of the water in nuclear reactor cooling loops by testing its conductivity?

author: wraper
author_rank: Unknown
timestamp: December 07, 2021, 01:17:03 pm
content: Quote from: m3vuv on December 07, 2021, 12:20:50 pmTap water isn't pure, conductive enough to light a bulb by passing the current through it by inserting 2 closely located electrodes. Even usual distilled water is significantly conductive, not even close to being an insulator.

author: themadhippy
author_rank: Super Contributor
timestamp: December 07, 2021, 03:12:18 pm
content: QuoteMake the electrodes movable and youve got a dimmer,add salt to the water to adjust the dimming curve to load.some claim this is were the term pot came from, as in the clay pots used to hold the liquid, and has nought to do with potential divider mumbo jumbo

author: SL4P
author_rank: Super Contributor
timestamp: December 07, 2021, 09:07:31 pm
content: Why the hell is it so important to charge your phone while you’re in the bathroom ?

author: rsjsouza
author_rank: Super Contributor
timestamp: December 07, 2021, 09:41:26 pm
content: Quote from: SL4P on December 07, 2021, 09:07:31 pmF.O.M.O.

author: tooki
author_rank: Super Contributor
timestamp: December 08, 2021, 07:44:33 am
content: Quote from: SL4P on December 07, 2021, 09:07:31 pmProbably to watch TV while soaking in the bath. I do that from time to time. But since I don’t have infinite funds to spend replacing drowned iPads, the iPad doesn’t actually sit anywhere where it could fall in, plugged in or not. I have a waterproof Bluetooth speaker I can use to bring the sound closer if needed. (But the charging port must be plugged shut to be waterproof, so it isn’t charged while in the bath.)

author: Watth
author_rank: Frequent Contributor
timestamp: December 08, 2021, 09:02:56 am
content: Quote from: SL4P on December 07, 2021, 09:07:31 pmBecause reasons, the point might not be to virtue signal here.

author: BrokenYugo
author_rank: Super Contributor
timestamp: December 24, 2021, 01:01:26 am
content: Interesting, these two were primary-secondary insulation tested to failure and both failed at the not a Y cap before the transformer broke down, that said they both had not completely terrible transformers.

author: jonpaul
author_rank: Super Contributor
timestamp: December 24, 2021, 10:18:12 am
content: Was the bathtub metal or plastic?Metal is well grounded via the faucets.Any Chinese product is made for one purpose: Cheapest possible that can still be sold. Most are desiged by inexperienced designers that only know how to copy.Safety and regulatory compliance is not considered.Jon

author: wraper
author_rank: Unknown
timestamp: December 24, 2021, 12:36:26 pm
content: Quote from: BrokenYugo on December 24, 2021, 01:01:26 amThose transformers ARE terrible. Even though they have an insulation between primary and secondary windings, construction quality is garbage since those windings touch each other where wires come out.

author: wraper
author_rank: Unknown
timestamp: December 24, 2021, 12:39:54 pm
content: Quote from: jonpaul on December 24, 2021, 10:18:12 amNonsenese. Most of the good quality chargers are made and often designed in China. The problem appears when you buy a $2 charger.

author: wizard69
author_rank: Super Contributor
timestamp: December 25, 2021, 12:21:06 am
content: Quote from: tooki on December 05, 2021, 09:13:44 pmActually if your skin is soaked from being in a tub, I would suspect that there is far lower resistance than normal dry skin. Not that I want to find out. You also have all the additives that end up in the water, soap, surfactants, salts and fragrances that does who knows what to conductivity. I once worked in a foundry, which was hotter than hell, and at times I dreaded some of the electrical work, especially debug. Every part of your body would be sweaty and that didn't leave me feeling comfortable around electrical work.Still the problem is how does the circuit complete. The negative and positive of a 5VDC source would need to be on opposite sides of the body with the body being the primary conductor. In this case I suspect AC leakages to ground through the plumbing. That seems plausible if somebody was touching metallic plumbing.

author: rsjsouza
author_rank: Super Contributor
timestamp: December 25, 2021, 01:51:00 am
content: Soaked skin will not affect much. Also, the soaps and suds on the surroundings of the skin will conduct the vast majority of the electricity - think of two resistors in parallel, one with Megohms (your body) and another with hundreds or maybe a couple of thousands of kilohms (the water). If you have a cut, then I would be much more worried.Being immersed in a medium with a given potential brings no harm to you - birds in HV wires are the ultimate example. The only problem is, if the bathtub is fully isolated and you hold a ground or neutral wire, current will want to flow through you (or perhaps simply through the soapy skin surface, giving a tingle).

author: wraper
author_rank: Unknown
timestamp: December 25, 2021, 01:06:18 pm
content: Quote from: rsjsouza on December 25, 2021, 01:51:00 amSoaked skin affects very much since dry skin has much higher resistance and basically is what limits the current thru the body.QuoteHuman body has orders of magnitude lower resistance than that.If bathtub is floating that will make it safer while you hold the live wire as there will be no current path. Earthed bathtub on other hand will provide that current path. The most dangerous situation will be if you hold the live wire (phone with faulty charger attached) while immersed into earthed bathtub.

author: Gyro
author_rank: Super Contributor
timestamp: April 08, 2022, 06:47:01 pm
content: Much as I hate to dredge up one of these threads, I just had to post a link to DiodeGoneWild's latest teardown video.The first one I've seen where the transformer haszerotape insulation between primary and secondary, not even a token attempt at meeting the isolation requirements! It uses cheap CCA wire too, just to increase the chances of overheating and insulation failure. Downright criminal!The transformer part starts at 11:45 if you don't want to watch the whole thing (he looks at two adapters).

author: Terry Bites
author_rank: Super Contributor
timestamp: April 09, 2022, 09:46:45 am
content: This why my submarine uses batteries.