Question about possible electrocution situation? Thanks for the help.

My wife has a bad habit of unplugging her power cord from her laptop after it's been fully powered. But not unplugging the cord from the outlet in the wall. I clean up after her every time she does this. I tell her she better be more careful. So I unplug the cord and put it away. This has happened more than 100 times at home.

Well, she did this at work (a classroom, she's a teacher) today and when she came back after lunch saw that the end of the power cord had carelessly landed in a bucket of water used to clean the chalk board. Luckily, they didn't touch the bucket or water, but unplugged the cord from the wall.

My question is could she have been electrocuted to death? Or just burned by the shock? What would've happened. This is by the way in an old middle school where I doubt they have new fancy circuit breakers or protection devices. I don't know the exact amount of voltage running through that power cord, but would it be that amount or the amount of the source? Would this have resulted in death?

I'm so angry at her now. I need to teach her a lesson and research what would've happened.

Thanks for the help.

Dave

Reply to
Dave Wang
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If someone had put their hand in the bucket and happened to be touching something metal that was grounded, then the result could have been painful. If they happened to be very young or in poor health it could have been fatal. The voltage in the cord would have been 120 volts. That is universal throughout the States now.

Since water is not a very good conductor the current drawn by the submerged cord might not have been enough to trip the breaker or blow the fuse (if the building is that old). If left for any length of time the water in the bucket would have got warm and eventually boiled. There would then be another hazard if it was unobserved for an hour or so. Somebody could then get scalded as well as getting shocked as they tried to remove the cord.

One solution might be to fit a plug to the wall end of the cord that is very easy to grip and pull out. So many are small and hard to grip. Try Home Depot for a BIG plug that just screams to be pulled out easily. Don't blame your wife too much. Women see these things differently from men!

Reply to
Rusty

This thing has a "brick" in the cable? The voltage at the end of laptop cords is usually 12-16v. Not a good thing to drop in a bucket of water but not particularly dangerous. I would worry more about dropping the laptop in the water.

Reply to
Greg

It is hard to say without knowing an extra bit of information. The type of laptop cord. If it is just a simple cord with 120VAC going straight through to the laptop, and the AC->DC power supply is internal to the laptop, then yes it could have been quite serious.

But that said, laptops that are like that aren't made any more as far as I know. In order to get the advertised weight down and keep the laptop as small as possible, they've put the AC->DC power supply in a 'brick' in the power cord. Often midway between the cord going to the wall outlet, and another cord going to the laptop. Now, if the DC plug from the laptop fell into the bucket of water, it may have damaged the power supply, but it is unlikely to have been lethal. Check the 'brick' label and it most likely lists the DC voltage of the output and it is probably less than 20VDC.

Of course, if the 'brick' itself fell into the bucket, then the 120VAC from the wall cord was also in the bucket.(and that would be hazardous).

Even modern classrooms don't necessarily have the 'new fancy circuit breakers' (the correct term would be a GFCI). They are only mandated in certain areas (kitchens, bathrooms, outdoors, etc...)

Although, having any electrical equipment near a bucket of water may not be the smartest thing.

daestrom

Reply to
daestrom

i consistently leave my cell phone charger plugged in and don't give it much thought. i unplug it when leaving for extended periods

have erasers gone out of style?

good metdodalogy. when in doubt be safe.

unlikely

Or just

unlikely

What would've happened.

it pretty hard to rig up a 12V circuit that hurt someone.

if the whole power supply fell in the water it is time to be nervous, but the main problem would be contamination to the device when is dried up, possibly causing failure.

This is by the way in an

assuming that the transformer is not faulty both voltage and current are limited to safe levels under foreseeable conditions. (you might be able to kill someone by applying the contacts directly to an open heart)

Would this have resulted in death?

calm down. have you ever seen the chemistry experiment where electrodes are placed in inverted test tubes in a salt solution and then DC is applied? the water separates into hydrogen and oxygen. the electricity in this case doesn't cause death and destruction.

if you simply must worry, if the exposed connector become shorted (like falling in a jar of paper clips) you have an elevated risk of fire hazard.

Tim

Reply to
TimPerry

"My question is could she have been electrocuted to death? Or just burned by the shock? " NO! As has been pointed out by others, the voltage is low and cannot cause harm. But, more importantly the low voltage is isolated from the power line by a transformer so it is impossible to create a gound fault where the line current can flow back through a person or device to ground. That's the kind of thing that can happen if an unisolated appliance like a hair dryer falls into a bathtub. The charger cord in a bucket is a non-issue and would not shock or hurt anybody or cause a fire, etc. Don't be so hard on your wife, leaving the charger plugged in causes no harm but it does eat a small amount of electricity. Bob

Reply to
Bob Eldred

On 2 Dec 2004 13:29:19 -0800, Dave Wang put forth the notion that...

Tell her to NEVER attempt to clean a chalkboard with water. It screws them up.

Reply to
Checkmate

| Tell her to NEVER attempt to clean a chalkboard with water. It screws | them up.

I've never had a problem with that. I just re-chalk them after cleaning and drying, then dry erase that and it's fine. It's just a bit labor intensive. But cleaning with water doesn't usually need to be done more than once every 1 to 3 months.

Reply to
phil-news-nospam

On Thu, 02 Dec 2004 23:13:17 GMT "Rusty" used 50 lines of text to write in newsgroup: alt.engineering.electrical

Is this true????

Reply to
G. Morgan

Do you always apply parking brake every time you park a car? If not, then you are just as guilty as she is. Those with minimal technical knowledge know that everything must have a backup. Unfortunately many of us so want to eventually kill someone as to rely only on the backup (which was even the reason why seven Challenger astronauts were murdered).

In the auto case, this tiny little spring loaded pin is suppose to keep a car from rolling? Pin is only the backup system. Parking brake must always be applied. But those who have no appreciation for life say, "No one has died yet".

As Greg noted, the brick includes internal safety designs that make electrocution and power supply failure not possible. If this was a straight power cord - no in-line brick - then she tried to kill someone.

Generally it is undesirable for a live brick to connect to the computer - under rare circumstances. And yes, she should always unplug the power cord. Some bricks (very rare) have even burned down the house.

But you cannot teach those who have a 'kill someone else' mentality. They say, "it did not happen yet so it will never happen". Then when someone is hurt, they erroneously call it an accident. Problem is, most of us have this 'we want to kill someone' mentality. Its not good to leave a power cord attached to a wall receptacle if that wall receptacle is not arc fault or GFCI type. It should not kill someone. Should not....

How do you park your car?

Dave Wang wrote:

Reply to
w_tom

A coworker of mine was once in a Central or South American developing country, and he said people had wires in their kitchen, with bared ends, which they would lower into a pot of water to boil it.

j
Reply to
operator jay

On Fri, 03 Dec 2004 18:00:25 -0600, G. Morgan put forth the notion that...

No.

Reply to
Checkmate

maybe it was soup :) according to this chart distilled water is at least

38 times a better insulator then air.
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this chart is a bit more elaborate
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Reply to
TimPerry

-------- Could be- not all that great but , in Canada and the US there are/were 120V humidifiers which were nothing more than plastic pots with two electrodes about 1/4 to 1/2 inch apart immersed in water. They worked well but one damn well better disconnect the supply before taking the top off to refill it with tap water. -- Don Kelly snipped-for-privacy@peeshaw.ca remove the urine to answer

Reply to
Don Kelly

alt.engineering.electrical

The problem with dielectric constant tables is that they list stuff classified as dielectrics, everything'll have a constant of one or greater. See if you can find some conductivity or resistivity number for "water". Tap water or something, not distilled. I bet you could come up with a resistance value, using R=resistivity*length/area or Conductance=conductivity*area/length type formulas (and some good old fashioned reckoning), that would make the bare wires in a pot of water thing seem feasible.

j
Reply to
operator jay

not exactly elegant. i wonder if they would still be making something like that.

Reply to
operator jay

I believe the "electrolytic" humidifiers were outlawed for home use in the US, but for commercial/industrial/OEM applications they have become very popular and sophisticated. Check out Nortec at

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Reply to
BFoelsch

| I believe the "electrolytic" humidifiers were outlawed for home use in the | US, but for commercial/industrial/OEM applications they have become very | popular and sophisticated. Check out Nortec at

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And who outlawed it? NFPA?

I guess I gotta have one now :-)

Ah, they do have residential models on that web site.

Reply to
phil-news-nospam

No, not NFPA, perhaps UL stopped listing them. There was a flap over them after a few people were injured after tipping them over, probably about 1965 or so.

Here's your big chance; there are two on ebay right now!!

3766133986 5540462044

Yup, I saw that. I suspect that Don Kelly and I were both thinking about the table-top models as shown in the ebay listings. I didn't realize Nortec got into the residential market.

Reply to
BFoelsch

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