USB near a bathtub

[steven765]

Given the changes coming with 2020.
Curious if the NEC would even apply to a USB only port next to a bathtub? Thinking of the leviton.com/en/products/usb4p-w
It doesn't supply class 1 wire, and those aren't receptacles in the power sense. It takes 120v internally so GFCI would be smart.

 

[WasGSOHM]

It takes 120v internally so GFCI would be smart.

5V @ 0.5A = 2.5W, 2.5W @ 120V = 21 mA, that works.
And for $15, why not, even if the USB is internally transformer-isolated?

 

[drcampbell]

The cost is low; the risk is high.

Teen dies from using cellphone while taking a bath

A Texas teen died Sunday morning while using her cellphone in a bathtub, according to reports. Madison Coe, 14, was electrocuted taking a bath at her father’s home in Lovington, New Mexico, n…

nypost.com

Even if it is internally transformer-isolated, there's no assurance that an insulation failure in that transformer won't pose a hazard.

 

[hbiss]

Too new to be addressed directly by the NEC but my thoughts are along the lines of Art. 680 where it addresses low voltage for spas and hot tubs.

USB 5 volt supplies often are of the cheapest design offering unreliable isolation between the mains and the output. Even well designed units are not designed to be used near water. I have no idea where the Leviton receptacle falls between these two but I wouldn't want to be sitting in a tub and have my phone fall in the water while charging from this device. So at the very least I would want an isolation transformer as specified in 680.23(A)(2). I would even go so far as to require that it be located remotely from the receptacle itself.

This of course if such a receptacle is allowed at all.

-Hal

 

[WasGSOHM]

The cost is low; the risk is high.

Teen dies from using cellphone while taking a bath

A Texas teen died Sunday morning while using her cellphone in a bathtub, according to reports. Madison Coe, 14, was electrocuted taking a bath at her father’s home in Lovington, New Mexico, n…

nypost.com

Even if it is internally transformer-isolated, there's no assurance that an insulation failure in that transformer won't pose a hazard.

Digging deeper:
MTBF for GFCIs?
MTBF for transformer insulation?

But, hbiss [a credible source] answered my question about isolation.

I'd consider that post article to be anecdotal data even if he had a GFCI upstream.

In my view the water in my bathroom sink was isolated from ground because of plastic feed lines, so just for laughs I ran a wire from the GFCI to the water. It tripped without any delay so it wasn't even close.

Since this kid is only 14, I say he does not get a Darwin Award.
21 and up, yeah.

 

[steve66]

It turns out it wasn't the cellphone or a USB at all, but a 120V extension cord:

First photo of extension cord that killed teen who died taking a bath while using cellphone | Fox News

I remember first hearing the story and thinking it was really unlikely that a USB could cause this.

 

[WasGSOHM]

it was really unlikely that a USB could cause this.

Give it time.
If more USBs are near bathtubs we'll have a front row seat to a huge social experiment involving a 5v source.

 

[K8MHZ]

Digging deeper:
MTBF for GFCIs?
MTBF for transformer insulation?

But, hbiss [a credible source] answered my question about isolation.

I'd consider that post article to be anecdotal data even if he had a GFCI upstream.

In my view the water in my bathroom sink was isolated from ground because of plastic feed lines, so just for laughs I ran a wire from the GFCI to the water. It tripped without any delay so it wasn't even close.

Since this kid is only 14, I say he does not get a Darwin Award.
21 and up, yeah.

I think it was a she.

 

[K8MHZ]

Give it time.
If more USBs are near bathtubs we'll have a front row seat to a huge social experiment involving a 5v source.

Right now 5G is more scary than 5V.

 

[WasGSOHM]

My bad, I only looked at the mug shot.

 

[WasGSOHM]

Right now 5G is more scary than 5V.

A lady from Germany called my frau about 5G anxiety. Does 5G use 2x the transmitter power than the old way (whatever the old way is)?

For years we both lived in a 200 mV per meter AM field.
And we're OK.
Right??

 

[K8MHZ]

My bad, I only looked at the mug shot.

 

[K8MHZ]

A lady from Germany called my frau about 5G anxiety. Does 5G use 2x the transmitter power than the old way (whatever the old way is)?

For years we both lived in a 200 mV per meter AM field.
And we're OK.
Right??

5G consumes 2 times more energy than 4G, but has less ouput power spread across a wider bandwidth.

 

[steve66]

Still a tragedy, even though its a little less scary knowing a USB didn't cause this (I assuming it was a phone that connected to a USB).

It must have been an older house without GFCI in the bathroom, or the extension cord must have ran to another room.

 

[K8MHZ]

Still a tragedy, even though its a little less scary knowing a USB didn't cause this (I assuming it was a phone that connected to a USB).

It must have been an older house without GFCI in the bathroom, or the extension cord must have ran to another room.

From what I read, the phone was connected to a 120V input to USB charger fed with an extension cord from another room and the phone dropped in the water.

 

[steven765]

So I believe this case was the driver behind the code change that an receptacle box cannot be within 36" of the tub surface. Which just got me thinking about USB. Well it's only 5v bleh who cares. Now the irony is with USB-C you have PD devices in the 4.0 spec going to 100W @20V so 5A.

 

[steven765]

A lady from Germany called my frau about 5G anxiety. Does 5G use 2x the transmitter power than the old way (whatever the old way is)?

For years we both lived in a 200 mV per meter AM field.
And we're OK.
Right??

5G is scary but not for those reasons. As non ionizing radiation I'm not worried about it. As a THz field, well now I can start to ask some real questions about the background and what it allows me to see.

 

[steven765]

The cost is low; the risk is high.

Teen dies from using cellphone while taking a bath

A Texas teen died Sunday morning while using her cellphone in a bathtub, according to reports. Madison Coe, 14, was electrocuted taking a bath at her father’s home in Lovington, New Mexico, n…

nypost.com

Even if it is internally transformer-isolated, there's no assurance that an insulation failure in that transformer won't pose a hazard.

True but that's ignoring the extra conductance of water still the same hazard. If it shorts and turns your USB into a 120V cord that's a big problem either way.

 

[hbiss]

True but that's ignoring the extra conductance of water still the same hazard. If it shorts and turns your USB into a 120V cord that's a big problem either way.

That's why you supply the transformer I mentioned in my post above from a GFCI protected circuit.

-Hal

 

[Hv&Lv]

Given the changes coming with 2020.
Curious if the NEC would even apply to a USB only port next to a bathtub? Thinking of the leviton.com/en/products/usb4p-w
It doesn't supply class 1 wire, and those aren't receptacles in the power sense. It takes 120v internally so GFCI would be smart.

You know, they make 10’ cell phone charger cords...
just sayin’