Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Mike Sokol]

http://www.discovery.com/tv-shows/mythbusters/videos/appliances-in-the-bath-minimyth.htm

Confirmed

There's also been a few recent examples of power lines falling into water on the street when a car hit a power pole, which then caused a voltage gradient to reach out a few hundred feet, killing at least one person who tried to help the driver. That's also why you want to have any outdoor metal stages grounded. If it was allowed to be biased to line voltage (120 here and 240 volts in the UK) by something like a pinched extension cord, then someone walking close to the stage while standing in a puddle of water could be electrocuted. I feel it's really important that all outside stages and generators are properly grounded and bonded for this very reason.

[Brent Gillespie]

As usual, the one picture does not tell the whole story.

These are actually Electrical Engineering students.

They went to great lengths to make sure this was safe before they did it, but you can't tell that just by looking at this photo. There is a whole write-up somewhere on the internet about what all they did to make sure it was safe. Based on what I read (when I read it several years ago) I figured it sounded safe enough I would probably get into the pool with them.



Things are not always as frighteningly awful as they first appear.

As a fulltime Firefighter I experienced a sort of "backlash"  due to a photo I was in a few years back.  Our rig responded to a busy intersection  for some wires down following a brief Summer storm.  On arrival we discovered a power line down and laying across he roof of a few cars at the stoplight.  Of course these people were terrified.  We secured the intersection  and intsructed the motorists to stay in their vehicles. They all complied but remained extremely anxious.  Mind you, we did not approach the cars directly.  We treat evey wire as if it is still energized and untill the utility company advises otherwise.  The power company arrived and cut the wire at the pole.  As the worker was winding the wire up I held it up over the vehicles roofs  while talking with the drivers.  Thats when the local paper decided to take a "cover" picture that ended up in the morning paper.  LOL !!     The pic with me in my gear holding onto a utility wire with it over my head above the motorists  looking as if I'm "saving the day" by holding a live wire !!  LOL .  Our fire chief recieved a number of phone calls that morning wondering what the heck one of his FF's was thinking.   

[Hayden J. Nebus]

Perhaps the pool is filled with mineral oil (for its dielectric strength), in which case I'm sure most of us would doubly agree with Mark's comment.

I still wouldn't get in.

[Stephen Swaffer]

For years it has been a common scenario in movies for an electrical item, usually a toaster, to be dropped into a bathtub in order to electrocute the occupant (either murder or suicide).

I wonder though what the reality is.  With the live connection in close proximaty to the neutral and ground connections, I'm sure it would short out internally and pose no threat at all to the occupant of the bath.

Any real world examples to confirm or bust my thoughts?

(I'm not going to try it!).


Steve.

Depends a lot on the conductivity of the water.  It takes 15 to 20 amps to trip a breaker (or 13 amps to blow a line fuse across the pond) plus the time to trip which varies with conductivity.  It only takes a few milliamps for a very short time to electrocute-there is a big range in conductivity between being able to kill you and being able to trip a breaker.

Reminds me of the guy that was killed a few weeks back showing off his bullet proof vest by getting shot-his friend missed the vest.  Why put yourself in harms way just to be cool and prove a point?

[Mike Sokol]

Reminds me of the guy that was killed a few weeks back showing off his bullet proof vest by getting shot-his friend missed the vest.  Why put yourself in harms way just to be cool and prove a point?

I'm no stranger to doing dangerous demonstrations. In my own No~Shock~Zone clinics I often electrify a microphone or guitar or even a 40-ft RV with up to 120-volts on its chassis. But I include a series resistor in the bias path which should limit the current to 5 mA or less, plus I put a GFCI on the incoming line which should trip if there's a fault to ground of more than 5 mA. And yes, it's still possible for something to go wrong, which is why I treat everything as if it could kill me (which it could). But I think it's important to show students how to use something like a NCVT to check for hot mics and guitars due to improper grounding.

Brent: But yes, if it's possible for the press to get a picture of you that's misinterpreted in the worst way possible, then that's what will happen. 

[Steve M Smith]

It takes 15 to 20 amps to trip a breaker (or 13 amps to blow a line fuse across the pond)

We do have RCDs as well as fuses!


Steve.

[Stephen Swaffer]

But yes, if it's possible for the press to get a picture of you that's misinterpreted in the worst way possible, then that's what will happen. 

A couple years ago, I was following an oversize load down the main drag in our small town.  Noticing he was brushing the street light drops,I wasn't surprised when he snagged one and snapped it.  Being in my work van, I pulled in to the adjacent park, and slipped on some leather gloves.  My observation, as I walked to the wire, told me it was not energized , but I verified with my NCVT anyway,  then pulled the wire off the road.  As I headed back to my van, the local police chief pulled up in his secret service style SUV.  I introduced myself and explained the situation and left.

That evenings paper featured a picture of our local hero on the front page-brave and bare handed removing the hazard to our community from the road.  How it got back on the road I can only guess-it wasn't there when he arrived!

I certainly mean no disrespect to law enforcement/first responders-but we all have our  days!

[Jonathan Kok]

You're right. With all that beer and testosterone one would think the babes would show up.

I believe this supplies the answer:

...
These are actually Electrical Engineering students.
...

[Jonathan Johnson]

Without knowing anything about the backstory of the OP photo (beyond what has been posted here), I'd venture that there are two possible conditions (no, make that three conditions) that render it safe:

• The water is extremely pure, making the resistance high enough that it's virtually an insulator;
• The water is extremely salty, making the resistance low enough that voltage gradients would be effectively minimized; or
• The electrical components aren't actually energized. Note that there's nothing in the photo to indicate that it is.

[Frank DeWitt]

That evenings paper featured a picture of our local hero on the front page-brave and bare handed removing the hazard to our community from the road.  How it got back on the road I can only guess-it wasn't there when he arrived!

I have had personal knowledge of a few things that were reported in the news.  From this I have come to be leave that the news usually gets the date at the top of the page right.  They also usually.......  Well they get the date right.

[ProSoundWeb Community]