Laptop vs. Bathtub

[Mr Happy]

So now that that's established, what would be an expedient DIY way to find out if your tub is grounded?

The risk only exists if a mains supply is involved. If the laptop is running on batteries it is isolated from the mains and grounding is not relevant.

That said, I'm not sure I know of a safe way to test for any ground paths in a bathtub. Any reliable test would involve the mains supply, and that is not something to mess with. If you know enough to work with the mains supply safely, then you will already know how to do such a test.

Even so, according to the electrical code any electrical outlet in an American bathroom should be on a GFCI. Therefore if there was enough leakage current to present a risk of electrocution the GFCI should cut out first.

In places such as the UK the electrical code prohibits any electrical outlets in bathrooms with the exception of a low power shaver socket fed through an isolation transformer. So unless you are crazy enough to run a long extension cord inside your bathroom you are not going to be running a laptop on the mains supply.

 

[TXArsonCop]

Once again, firefighter with plumbing experience NOT an electrician.

I agree with Mr Happy's post(s) as I have from the beginning, he's one of the few who understood the issue all along.

I will say that the one way I know of to test if the tub hardware (if the tub is plastic/composite) or the tub, if it's cast iron, would be to use a multimeter. You would test for continuity from the metal portion of the tub in question to the ground connection (the one shaped like a D on its side) of the nearest plug.

Of course this would only work if it was grounded to the electrical! It could be grounded in other ways incidentally. Metal lathe for plaster in contact with the piping somehow grounded to earth: contact with rebar in slab, contact with copper supply piping...

Most of the time grounded supply piping wouldn't matter unless you came into contact with the faucet, valve or showerhead while something energized was in the tub.

If your sinks have plastic P-traps and they're not connected to metal piping coming out of the wall you probably have PVC D/W/V pipes.

Remember, firefighter with plumbing experience who has not personally inspected YOUR home.

 

[ktm032]

The move follows just two months after the deaths of two children who died when they dropped a hair-dryer into the water as they played in the bath in Germany.

The sisters - aged four and six - were discovered by their mum when she realised their bath time play had gone quiet suddenly. Paramedics in Lustadt were unable to revive the girls who electrocuted themselves when they dropped a hair dryer into the tub.

Im pretty sure that uk has strict standards of gfi's and metal piping...

This is a news story none the less...

Im sure the ac will kill you with sufficient current...

Dc will do it at a lower voltage and current...

I correct myself as stated above(sorry about the rude comment(s))....

The laptop would short out and render useless.

What if the user tried grabbing the ac cord with wet hands and then this is the game ender. Otherwise the laptop would not kill you but shock you a little but as most have said on here it only takes 36v to kill a person.

Here's another scenario since water alone has a high resistance. What if the water were softened by salt and then would make the water highly conductive. then the human in the water would have a higher resistance and then poof. Could this change the scenario?

 

[StarHalo]

My wife definitely wouldn't be using the mains to power anything near a tub, and even if that were to happen, there are many redundant layers of safeties (GFCI socket, pre-circuit breaker, circuit breaker, not counting whatever safety mechanisms are in the laptop's power brick). I'm mostly concerned with all the voltage/amperage that's moving around in a battery-powered laptop and what it'd do once it's submerged and shorting. But from what I'm gathering, as long as the tub isn't grounded, even a worst-case scenario would have no effect on the bather..

 

[Mr Happy]

I'm mostly concerned with all the voltage/amperage that's moving around in a battery-powered laptop and what it'd do once it's submerged and shorting. But from what I'm gathering, as long as the tub isn't grounded, even a worst-case scenario would have no effect on the bather..

If the laptop is running on batteries the question of grounding in the plumbing is not relevant. There is no danger to the person as all the voltages are contained within the laptop case and cannot escape.

The worst case scenario, if there is one, is that you disassemble the laptop while in the bathtub in an attempt to repair it, and while doing so you grab hold of oppositely charged conductors with either hand. I hope we can discount that scenario

 

[TXArsonCop]

The move follows just two months after the deaths of two children who died when they dropped a hair-dryer into the water as they played in the bath in Germany.

The sisters - aged four and six - were discovered by their mum when she realised their bath time play had gone quiet suddenly. Paramedics in Lustadt were unable to revive the girls who electrocuted themselves when they dropped a hair dryer into the tub.

Im pretty sure that uk has strict standards of gfi's and metal piping...

This is a news story none the less...

Ok, while ANY avoidable death is tragic... UK standards really have no bearing on systems in Germany. And homes anywhere on the european continent can be hundreds of years old; meaning cobbled together infrastructure. Although of any country I would expect Germany to be the most squared away, with the exception of the former East Germany.

Im sure the ac will kill you with sufficient current...

Dc will do it at a lower voltage and current...

I correct myself as stated above(sorry about the rude comment(s))....

The laptop would short out and render useless.

What if the user tried grabbing the ac cord with wet hands and then this is the game ender. Otherwise the laptop would not kill you but shock you a little but as most have said on here it only takes 36v to kill a person.

Here's another scenario since water alone has a high resistance. What if the water were softened by salt and then would make the water highly conductive. then the human in the water would have a higher resistance and then poof. Could this change the scenario?

Again, I was an eyewitness AND participant in a routine experiment given by a public safety training group (PATC). The instructor put a turned on and running blow dryer (plugged into the wall) into the water. Whereupon the GFCI plug on the BD did not open, instead the BD kept running and began to heat and circulate the water. All this time the instructor held the BD and/or the cord with one and/or both wet hands as he splashed merrily away astonishing approximately 50 fire/arson investigators. He then asked for a volunteer, everyone was still skeptical so I did. He called me up and told me to put my hands in the water. I did so and am still here typing this post today, that was 5+ years ago. The water was pleasantly warm....

As I previously mentioned, water softened by salt will give you a 'tickle,' per my personal experience at home via the demo for wifey. Our water averages 100+ grains of hardness prior to softening requiring a 'commercial' system and uses A LOT of salt. I don't know how much is in the water but I know you don't want to drink it! :sick2:

As a refresher I built my house in 2001 and dad & I put in PVC D/W/V and poly supply tubing, no ground potential through the plumbing at all. I get zapped a LOT harder by the 'electro-stim therapy' I get at the chiropractor.

If you're gonna end up in the water with electronics I recommend CLEAN and naturally SOFT water.