Bathtub tv

wyreman

Senior Member
Location
SF CA USA
My friend was in Las Vegas and told me there was a hotel tv on the wall right inside by the bathtub.
I know some tile guys that cut tile with a skill saw using running water, standing right in it.
Do all these depend on double gfis or are they just crazy?
someone sitting in the tub is very conductive
same with the wet boots

sounds crazy!

would a Gfi do anything if the is was a standard metal tub or would the person be So conductive it wouldn’t matter
 

wyreman

Senior Member
Location
SF CA USA
And the difference between tv outlet in bathtub
and the GFI protection for a fan or light above the bathtub or in the shower
Is that if you’re sitting in the tub or using the skillsaw
You have more chance to get in-between the phase wire & the neutral

compared to when you are standing on the tub changing a lightbulb
in that case, flow would have to be going the long way thru the metal pipe And trip the Gfi

but still, 5ma and wet feet
‘how is that safe with the Gfi protection for light above shower / tub?
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
A tub TV almost certainly has a low-voltage supply feeding it.
i didnt think there were anymore true 120V televisions.
the 120 goes directly to a LV power supply. Now where the power supply is located on some models is inside the TV, on some it is a brick like a PC.
I have a small TV like this that is 12VDC from Walmart. I cut the 120V end off and spliced a cigarette lighter end on the TV cable. I use it for a screen extension for my PC in my truck
 

ptonsparky

Senior Member
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
Electrical Contractor
I had to use my bookkeepers computer. One display and we are trying to cut back on paper so at least two programs on at a time. I can’t see stuff on it. She was given the option of two or one big.

’Bigger is always better’ was the reply.
Should have known.

32” on a small remote power supply. Didn’t look for voltage but I will now.
 

kwired

Electron manager
Location
NE Nebraska
Have read a story or two about people being electrocuted in the bath tub from cell phone that was plugged into USB cable style charger. Low volts isn't the only thing that matters, ground references definitely are important.

And there is a huge difference between standing on a wet surface and being totally/mostly immersed into the water when you do contact something at different potential than the water.
 

kwired

Electron manager
Location
NE Nebraska
And the difference between tv outlet in bathtub
and the GFI protection for a fan or light above the bathtub or in the shower
Is that if you’re sitting in the tub or using the skillsaw
You have more chance to get in-between the phase wire & the neutral

compared to when you are standing on the tub changing a lightbulb
in that case, flow would have to be going the long way thru the metal pipe And trip the Gfi

but still, 5ma and wet feet
‘how is that safe with the Gfi protection for light above shower / tub?
NEC does not require GFCI for the light over the shower/tub. It does have height restrictions on certain luminaire types in particular pendant types.

GFCI protection is often mentioned in the instructions for most vent/light and similar units but that would be a 110.3(B) follow the instructions thing from an NEC perspective.

If you are sitting in tub that is filled with water and using a skilsaw, you deserve a Darwin award. If you are in an empty tub but there may happen to be a little water on the surface, this is no different and in some cases maybe even safer than using same saw outdoors on wet/damp ground.

If you do contact a GFCI protected hot conductor you still potentially getting a pretty good shock before the GFCI breaks the circuit, but at least the circuit is going to open rather quickly where a non GFCI protected circuit needs to draw over 15 or 20 amps before even beginning to think about any tripping process.
 

synchro

Senior Member
Location
Chicago, IL
Occupation
EE
And there is a huge difference between standing on a wet surface and being totally/mostly immersed into the water when you do contact something at different potential than the water.
This is how they needed to get maximum electrical coupling to the heart when using the earliest electrocardiograph machines, which were not very sensitive. So it's also probably one of the worst case configurations for getting electrocuted with an external electrical source. So don't do this at home!

 

Besoeker3

Senior Member
Location
UK
We have quite a nice upstairs bathroom. A TV in there?
No way. I only ever use that shower.
But the grand kids like to frolic around in it especially with that sprayer.

 

wyreman

Senior Member
Location
SF CA USA
What about the GFI on the cord cap of the new hairdryers?
That’s supposed to make them safer but you can still get in between the black and the white, I guess.
I would’ve thought that when the hairdryer drops in the tub that power flows through the metal piping and open the GFI mediately.
It looks like it’s the white wire in the GFI Can’t see, so what’s the thinking behind putting the GFI and all the Cord caps for the hairdryers
 

romex jockey

Senior Member
Location
Vermont
I haven't watched TV in years , so it's hard for me to imagine

i mean , i can think of only one activity i'd be doing where i'm sitting in one place to even be able to watch tv

so the whole practicality of it escapes me , unless you guys claim the news these days keeps one errumhh....regular....:poop:~RJ~
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
That’s supposed to make them safer but you can still get in between the black and the white, I guess.
That can happen in any circuit, unless you need to protect from a current that exceeds the OCPD rating, which the OCPD does.

I would’ve thought that when the hairdryer drops in the tub that power flows through the metal piping and open the GFI mediately.
It should. Two currents will flow through the black wire. One is black to white, which a GFCI will ignore. The second is black to, well, the rest of the world, whether it be human, water, piping, earth, etc, which is what a GFCI is designed to detect.

It looks like it’s the white wire in the GFI Can’t see, so what’s the thinking behind putting the GFI and all the Cord caps for the hairdryers
I don't understand what you're saying or asking here. A cord-type GFCI functions identically to a receptacle- or breaker-type GFCI.

The EGC is only relevant to a plug-in GFCI tester, because it doesn't have access to the neutral ahead of the current-sensor ring.
 

kwired

Electron manager
Location
NE Nebraska
What about the GFI on the cord cap of the new hairdryers?
That’s supposed to make them safer but you can still get in between the black and the white, I guess.
I would’ve thought that when the hairdryer drops in the tub that power flows through the metal piping and open the GFI mediately.
It looks like it’s the white wire in the GFI Can’t see, so what’s the thinking behind putting the GFI and all the Cord caps for the hairdryers
Hair dryer drops in tub, if there is no continuity between the water and ground is very possible nothing happens, has to be current leaving one side of the GFCI and not returning to the other side of the GFCI before there is going to be any activity that initiates a trip. Once that current exists it still takes time for everything to function and open the circuit. That time is in millisecond ranges but is still enough time you can get shocked if you are part of any current path. Key thing here is it does detect and open circuit very quickly vs not opening at all if you don't have GFCI.

Why the cord end GFCI's - believe it or not there are still many places with no GFCI protected outlet to plug it into. May be less places than it was when they first started putting those devices on the cord end - which was like 30-35 years ago I believe. Just one more layer of protection mostly for when there is no protection otherwise.
 

SceneryDriver

Senior Member
Location
New York, NY
Have read a story or two about people being electrocuted in the bath tub from cell phone that was plugged into USB cable style charger. Low volts isn't the only thing that matters, ground references definitely are important.

And there is a huge difference between standing on a wet surface and being totally/mostly immersed into the water when you do contact something at different potential than the water.
Those stories were almost certainly caused by dodgy USB power supplies that had a direct connection between mains and the 5V output. They're supposed to be galvanically isolated switchmode power supplies, but either through bad design, bad construction, or damage, that isolation no longer exists.

Here's an excellent video that explains what can happen:


SceneryDriver
 
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