Don't Charge Your iPhone In The Bathtub

Every AC to DC power adapter has a transformer coil, rectifier bridge, and filter capacitors. If the phone was immersed in water it's possible to have created a near dead-short condition on the DC terminals. This would have overheated the transformer coil, possibly causing a short between the high and low voltage coils. Assuming the diodes didn't blow out immediately, you'd then have about 240V AC being turned into 240V DC going into the water, with a large current spike from the short just prior to blowing out a house fuse or circuit breaker. A few milliseconds at 240V is all it would take to deliver enough current at a fatal level prior to the charger failing catastrophically and cutting off the current flow, or the AC supply being cut by a breaker or fuse. Electrical safety devices do not work immediately, and devices like chargers and other DC transformers don't necessarily fail instantaneously if they short out. It only takes around 40 milliamps to stop the heart. You could have over a full amp going through those wires, the water, and grounding out through the tub for a hundred milliseconds or more before the power adapter failed completely. That's more than enough to stop the heart and cause immediate death.

People think that just because it's low voltage, low current going into the device that it's safe. It's not. Now matter how safe they try to make things, the fact remains that if it's plugged into the wall it can kill you.
 
Phoenix333 said:
<saving space>
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Killing you doesn't occur instantly, though. You can survive a bit even under high amps. I'm not sure exactly how long though...
http://electronics.stackexchange.com/questions/19103/how-much-voltage-is-dangerous
This guy says 3 seconds under 500mA. Not sure if that's right. 240VDC over 300 + C (water) resistance is somewhere under 800mA. That's kind of a long time in electrical circuits. Signals happen on the order of nanoseconds or femtoseconds sometimes...
 
StoleMyOwnCar said:
As for Darwin Awards... there actually is a similar one. He basically took both ends of a DMM and shoved it into "measure resistance" mode:
http://www.darwinawards.com/darwin/darwin1999-50.html
Never got to record his Ohms.
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No.

By the way, the Darwin Awards is not the most reputable source of information on the Internet.

Let's all go over the witness report again:

“I walked in and saw her lying there all pale in the water. Her phone was also in the water. I pulled my friend out and noticed that her body was shaking from the shock,” Dubinina was reported as saying.

How did the roommate avoid being electrocuted while pulling a body out of water that was being shaken by electric shock? No, no, this is all wrong.
 
Zepher said:
240v is safer than 120v btw.
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Needs more context, what are you referring to? Putting 240V of potential across any two spots on your body will drive more current than putting 120v of potential across those sames points.
 
Zepher said:
less amps
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Your responses are far too brief. Less amps where? When? How?

Typical appliances designed for 240V and for a fixed power usage use less current. This means the wires used for 240V usually don't need to be rated for as high of currents as 120V. Is this what you are referring to?

If you grab 240V terminals and then compare by grabbing 120V terminals I guarantee you will measure more amps running across you with the 240V terminals. In that case 240V is more dangerous than 120v.
 
You hold either long enough it'll kill you.
I was just saying that the circuit breaker, which limits current, will be less in a 230/240v house, since it will have less amps available, probably half of what a 120v home would have.
Now I know US homes have 240 coming in, I am talking about the voltage at the outlet.

It doesn't really matter as 1/2 an amp can kill you.
 
Zepher said:
You hold either long enough it'll kill you.
I was just saying that the circuit breaker, which limits current, will be less in a 230/240v house, since it will have less amps available, probably half of what a 120v home would have.
Now I know US homes have 240 coming in, I am talking about the voltage at the outlet.

It doesn't really matter as 1/2 an amp can kill you.
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Thanks for the complete response. Typical human body resistance is measured in tens or hundreds of thousands of ohms. Wet skin may drop this to a thousand. Even if you assume 100 ohms:

Vrms = Irms*R

240V / 100 ohms = 2.4 amps (rms)

What are typical european circuit breakers rated for?
 
serpretetsky said:
Thanks for the complete response. Typical human body resistance is measured in tens or hundreds of thousands of ohms. Wet skin may drop this to a thousand. Even if you assume 100 ohms:

Vrms = Irms*R

240V / 100 ohms = 2.4 amps (rms)

What are typical european circuit breakers rated for?
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Honestly, I can't remember, I'd have to google it. I moved back to the US 23 years ago.
 
Zepher said:
240v is safer than 120v btw.
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Impedence of your body wouldn't change. Double the voltage = double the current. Slew rate is higher with 240V 60Hz too so it probably hurts even more too.

What the circuit breaker is doesn't matter. It doesn't take 10A to end you.
 
Phoenix333 said:
Every AC to DC power adapter has a transformer coil, rectifier bridge, and filter capacitors. If the phone was immersed in water it's possible to have created a near dead-short condition on the DC terminals. This would have overheated the transformer coil, possibly causing a short between the high and low voltage coils. Assuming the diodes didn't blow out immediately, you'd then have about 240V AC being turned into 240V DC going into the water, with a large current spike from the short just prior to blowing out a house fuse or circuit breaker. A few milliseconds at 240V is all it would take to deliver enough current at a fatal level prior to the charger failing catastrophically and cutting off the current flow, or the AC supply being cut by a breaker or fuse. Electrical safety devices do not work immediately, and devices like chargers and other DC transformers don't necessarily fail instantaneously if they short out. It only takes around 40 milliamps to stop the heart. You could have over a full amp going through those wires, the water, and grounding out through the tub for a hundred milliseconds or more before the power adapter failed completely. That's more than enough to stop the heart and cause immediate death.

People think that just because it's low voltage, low current going into the device that it's safe. It's not. Now matter how safe they try to make things, the fact remains that if it's plugged into the wall it can kill you.
Click to expand...

Even if this was the case, and assuming there's no GFCI (which being russia I wouldn't be surprised if their electrical codes are sketchy), the time it would take for the transformer to catostrophically fail to the point it fails-short would probably be at least a second or more. What's the first reaction of someone who drops their phone in water? Get it out of the water!

This sounds like a CSI show. To me it would seem the chick died for whatever reason, and then the phone in the water maybe happened after she was dead and lost grip.
 
StoleMyOwnCar said:
Killing you doesn't occur instantly, though. You can survive a bit even under high amps. I'm not sure exactly how long though...
http://electronics.stackexchange.com/questions/19103/how-much-voltage-is-dangerous
This guy says 3 seconds under 500mA. Not sure if that's right. 240VDC over 300 + C (water) resistance is somewhere under 800mA. That's kind of a long time in electrical circuits. Signals happen on the order of nanoseconds or femtoseconds sometimes...
Click to expand...

A lot of it depends on the individual and the circumstances. One person you could put a few amps through and have them be fine, the next person might have a heart or neurological condition that causes their heart to stop at the slightest shock. It also depends where the electricity goes. Touching contacts that only send a jolt across one end of your finger probably won't kill you. Having the current travel through your body and across the heart or spinal nerve bundle and it's anyone's guess. That's why one must assume the lowest common denominator when it comes to proper electrical safety. If a specific level of exposure is enough to kill one person you have to assume it's enough to kill any person.
 
I still can't understand how anyone would think it's a good idea to bring their electronic devices into the bathroom, much less wiring a charger to the bathroom.
 
Phoenix333 said:
A lot of it depends on the individual and the circumstances. One person you could put a few amps through and have them be fine, the next person might have a heart or neurological condition that causes their heart to stop at the slightest shock. It also depends where the electricity goes. Touching contacts that only send a jolt across one end of your finger probably won't kill you. Having the current travel through your body and across the heart or spinal nerve bundle and it's anyone's guess. That's why one must assume the lowest common denominator when it comes to proper electrical safety. If a specific level of exposure is enough to kill one person you have to assume it's enough to kill any person.
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yeah no, NOBODY could survive one amp much less a few amps
 
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