EEVblog #873 - World's Most Dangerous Consumer Product!

[Stonent]

There is an even more dangerous device being sold on ebay:



Yes, those exposed electrodes are live at (rectified) mains voltage.

Big Clive has also reviewed this on his YouTube channel (look for "Deadly quack water tester"). He has a hilariously unhealthy fascination with stupidly lethal bits of apparatus.

Other gems include the 'suicide shower' and the Turkish 'stinger' kettle which both connect mains voltages directly into water.

[Tac Eht Xilef]

this is a derivative of the old well known Soviet DYI things.

DYI? "Do Yourself In"?

[JoeN]

They've sold quite a few more now. 

[f4eru]

The "suicide shower" is quite common in some countries. It's a very clever device, even if dangerous by western standards.
The designers should have included a longer cable, so the (often poorly made) connections would not lie directly over the shower.
The earth connection could have been doubled.
Also keep in mind that the countries where this is sold often do not use GFCI protection.

My favorite picture of an installation of this device :

[Smokey]

You probably either had really hard water or they were specing the wattage for 110V not 220.  The other dude that tested one of those had the wattage numbers come out much closer at first.

[Samogon]

I remember, when I was a student (in 90th), some students in our campus (far from home, no money at all, too big brains, no fear for life...) made those dangerous heaters from 2 stainless raizor blades, 2 wood matches (as a spacers), 2 wires and a thread. Moreover, when there was no wall electricity plug in a room, they attach wires to a lamp... They knew what they were doing, how dangerous it was, so nobody was killed, but sometimes the electricity shut down on the whole floor of the building due to overcurrent...

I thought these days have passed long time ago.

We did it in our dorm too. 3Liter jar in 10 seconds boiling water. No one was killed.

[Lamp]

Actually I would use this or something like this to heat a bathtub in an emergency or something like that... but I think I would stay outside and have a switch outside and keep the door locked while it was cooking.

[EEVblog]

You probably either had really hard water or they were specing the wattage for 110V not 220.  The other dude that tested one of those had the wattage numbers come out much closer at first.

The package says 220V

[hayatepilot]

Actually I would use this or something like this to heat a bathtub in an emergency or something like that... but I think I would stay outside and have a switch outside and keep the door locked while it was cooking.

Wouldn't thad trip the RCCB in any modern building?
Since the drain is grounded the breaker would kick in immediately.

[RGB255_0_0]

Actually I would use this or something like this to heat a bathtub in an emergency or something like that... but I think I would stay outside and have a switch outside and keep the door locked while it was cooking.

Wouldn't thad trip the RCCB in any modern building?
Since the drain is grounded the breaker would kick in immediately.

If the bath was ungrounded, no.

NEC specifies water areas must have metal bonded to the EGC so you can not use a plastic plug and plastic surrounding the plug in a fibreglass bathtub as the metal must be bonded to a perfection device; you must have a permanent metal fixture in a pool bonded to the EGC and an exponential grid.

So without a leakage current you wouldn't trip

[Fungus]

Actually I would use this or something like this to heat a bathtub in an emergency or something like that... but I think I would stay outside and have a switch outside and keep the door locked while it was cooking.

Wouldn't thad trip the RCCB in any modern building?
Since the drain is grounded the breaker would kick in immediately.

Maybe.

You could always do it in a plastic bucket.

[chrism2010]

And if you're using one of those "suicide shower" heaters, don't forget the earth connection!!

[k4rlhp]

Wouldn't thad trip the RCCB in any modern building?
Since the drain is grounded the breaker would kick in immediately.

If the bath was ungrounded, no.

Okay, lets make things more interesting 
My claim is that the 'technology' is fairly safe and not as dangerous as you try to portray (when used properly, of course).

1. there are tons of commercial solutions for consumer and industrial market employing this method. I can send you a picture of an industrial heater rated for 25kW used to either heat utility water or provide heating to HVAC systems (NB! directly coupled via conductive liquid to metal fixtures like radiators or kitchen taps). If you want, I can sell it to you for €300 + shipping, it's perfectly functional.
2. falling water does not conduct due to formation of droplets (shower case). Else, everybody who walks out during thunderstorm would already be toast meat a'la hotdogger.
3. water is fairly poor conductor so the resistor network it forms in between the electrodes, human body and the grounding point (fault current) wont normally pass current or potential to matter (e.g. even to trip the RCCD fault current condition).

Obviously, using intrinsically unsafe device (i.e. broken or some hacked/smacked device) will be just as dangerous as with any other home appliance. So if you are stupid enough to heat water in your mouth with this method using two spoons in your mouth connected to mains, then you deserve to die and relieve us from further contamination in gene pool.

Hopefully this stirs things up a bit

[AhhhChoo]

I'm with Rolycat, nothing much else can exceed this one ..

<https://www.youtube.com/watch?v=ASnLL6ebaco>

[AhhhChoo]

Maybe china's idea (isolation from the rest of the world) is no bad thing after all ?

[mikerj]

Too bad they don't isolate their products as well.

[Nerull]

Wouldn't thad trip the RCCB in any modern building?
Since the drain is grounded the breaker would kick in immediately.

If the bath was ungrounded, no.

3. water is fairly poor conductor so the resistor network it forms in between the electrodes, human body and the grounding point (fault current) wont normally pass current or potential to matter (e.g. even to trip the RCCD fault current condition).

Were this true, electrocution in water would never happen. Yet, it does.

http://www.nbcnews.com/news/us-news/swimming-pool-safety-electrocutions-raise-alarm-summer-n112521
http://lakeexpo.com/news/lake_news/swimmer-electrocuted-at-lake-of-the-ozarks/article_25de24fe-1929-11e5-8ca0-0ff78a16476d.html

UL estimates electricity in water travels about 2 ft per volt, and if you're within that voltage gradient you are at risk, especially if you touch a ground.

Electrocution of swimmers near docks is disturbingly common. A live wire can energize a large area of water, and if a swimmer anywhere nearby touches a metal railing or other grounded object, they are likely to get shocked.

You really shouldn't handwave away electrical safety issues you don't know anything about.

[JoeN]

1. there are tons of commercial solutions for consumer and industrial market employing this method. I can send you a picture of an industrial heater rated for 25kW used to either heat utility water or provide heating to HVAC systems (NB! directly coupled via conductive liquid to metal fixtures like radiators or kitchen taps). If you want, I can sell it to you for €300 + shipping, it's perfectly functional.

What country is this all common in exactly?

[f4eru]

NEC specifies water areas must have metal bonded to the EGC so you can not use a plastic plug and plastic surrounding the plug in a fibreglass bathtub as the metal must be bonded to a perfection device; you must have a permanent metal fixture in a pool bonded to the EGC and an exponential grid.

So without a leakage current you wouldn't trip

That'S in the US. In a lot of countries you can use electrically isolated metal taps. In EU, you can use indifferently PE and metal pipes, and you have to ground the main water distribution point if it is metal, and big metal parts in the wet room. 30mA RCDs are mandatory for everything in the wet room, and there are minimal distances from the water outlet to any electrical appliance (no electrical shower head allowed)

Besides, in France, 30mA RCDs are mandatory for the whole house., and that's a good thing.

1. there are tons of commercial solutions for consumer and industrial market employing this method. I can send you a picture of an industrial heater rated for 25kW used to either heat utility water or provide heating to HVAC systems (NB! directly coupled via conductive liquid to metal fixtures like radiators or kitchen taps). If you want, I can sell it to you for €300 + shipping, it's perfectly functional.

It's functional but not allowed in many countries. Can you post us a photo of the label to see the safety marks ?

2. falling water does not conduct due to formation of droplets (shower case). Else, everybody who walks out during thunderstorm would already be toast meat a'la hotdogger.

Not guaranteed. Depends on distance to the shower head. And obviously you can touch the shower head, so you will get toast.

3. water is fairly poor conductor so the resistor network it forms in between the electrodes, human body and the grounding point (fault current) wont normally pass current or potential to matter (e.g. even to trip the RCCD fault current condition).

Wrong. Pure water is a good insulator. But it's also a very very very good solvent, so it does not stay pure for very long. As soon as it's not pure any more, it conducts. Tap water always conducts with various resistivities.

[mux]

I made a video just now to explain this phenomenon of ionic conductivity in water. It's an extremely strong effect, because water is not just a very good polar solvent, but ionic pathways tend to open up especially on voltage gradients and you really don't need much in the way of dissolved ions to get into the low-ohms volume resistivity of water.

Try it out for yourself! Science the shit out of it!

https://youtu.be/exn90L95dgI

[rch]

I made a video just now to explain this phenomenon of ionic conductivity in water. It's an extremely strong effect, because water is not just a very good polar solvent, but ionic pathways tend to open up especially on voltage gradients and you really don't need much in the way of dissolved ions to get into the low-ohms volume resistivity of water.

Try it out for yourself! Science the shit out of it!

https://youtu.be/exn90L95dgI

Thanks for the video.  But would it be a good idea to omit 'EEVBLOG'  from the Youtube title?   It has the potential to confuse.

[RGB255_0_0]

https://youtu.be/exn90L95dgI

What do you use for a fork?

[rrinker]

 The principle was used for light dimming applications such as theater lighting way back when.

http://www.compulite.com/stagelight/html/history-5/salt-dimmers.html

[mux]

Thanks for the video.  But would it be a good idea to omit 'EEVBLOG'  from the Youtube title?   It has the potential to confuse.

I personally don't see the problem (it has pretty much exactly the format of response videos when Youtube still had that as a thing), but I asked Dave if he'd like it to be removed.

What do you use for a fork?

You mean the PCB to the left of my plate?

The principle was used for light dimming applications such as theater lighting way back when.

http://www.compulite.com/stagelight/html/history-5/salt-dimmers.html

Now that is cool. And genius as well; you can make massively high power variable resistors with that method for pennies worth of material. The fluid can simply be recirculated across a big heatsink to get rid of the heat.

[EEVblog]

Thanks for the video.  But would it be a good idea to omit 'EEVBLOG'  from the Youtube title?   It has the potential to confuse.

He's got "Re:" in the title, so that's ok.