Bathtub tv

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kwired

Electron manager
Location
NE Nebraska
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
The cheap charger adapters you can buy at dollar stores and convenience stores - no way they are poor design or easily damaged :)
 

Besoeker3

Senior Member
Location
UK
Occupation
Retired Electrical Engineer
That never stopped anyone over here, extension cords and lamp socket to receptacle adapters are miracle products :)
Yes, but we operate at nominally 230Vac here for all domestic appliances.
 

kwired

Electron manager
Location
NE Nebraska
Technically the plug on a hair dryer only offers 'immersion protection'. This is why it must be plugged into a GFCI protected circuit.
So is it GFCI type design or something else in there? I always presumed they were still looking for unbalance current just like a GFCI does, not sure if has same trip threshold as a GFCI. If this is so, and you have sink, tub, or whatever you are immersing it into is insulated from other potential, you should be able to immerse the appliance and it won't trip because there is no current leakage to anything outside the protected circuit.
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
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
You know you have voided the UL listing for that cable, right? :D
 

kwired

Electron manager
Location
NE Nebraska

kwired

Electron manager
Location
NE Nebraska
How many tubs are metallic anymore?
Anyone seen metallic plumbing lately?
Any exposed metallic parts on that low voltage tv?
Done a bathroom remodel recently - it had copper drain pipes, original install probably late 60's early 70's.

Had a customer a while back complaining about a slight tingling in feet when in the shower. Shower had metal drain fitting but non metallic piping after that fitting - but eventually tied into old metal piping again before leaving the house. First time I was there I couldn't find anything. Second time I was there (after doing some thinking of what to check) I actually turned the shower on and got a small voltage from water to the metal drain fitting. This was same volts measured from service neutral to remote earth. Was not very high, and from recollection I had similar reading at my house.

I bonded that metal drain fitting to the metal water pipes and things have been fine since. I think just the flow of water in the drain pipe gave enough continuity to cause problems.

The wife was the one that mentioned she could feel it, the husband said he never felt anything.
 

mwm1752

Senior Member
Location
Aspen, Colo
Since receptacles cannot be over a tub 406.9(2)(c) and some designer insist on a tv to watch at the base of a tub - the only remedy I've seen is to separate the TV & receptacle from the room with a clear tempered glass plate. In real terms a wall/ barrier in between the tub and another room that may have receptacles & appliances in that room is compliant with NEC. The glass barrier would be no difference, the TV & receptacles can only be accessed in another room. -- an appliance in the bathroom only needs to be plugged into a gfi protected recept per 210.8(A) 7 & 9
 

kwired

Electron manager
Location
NE Nebraska
Since receptacles cannot be over a tub 406.9(2)(c) and some designer insist on a tv to watch at the base of a tub - the only remedy I've seen is to separate the TV & receptacle from the room with a clear tempered glass plate. In real terms a wall/ barrier in between the tub and another room that may have receptacles & appliances in that room is compliant with NEC. The glass barrier would be no difference, the TV & receptacles can only be accessed in another room. -- an appliance in the bathroom only needs to be plugged into a gfi protected recept per 210.8(A) 7 & 9
Where does the bathtub space end when you have a whirlpool tub with tile surface completely surrounding it? This surrounding deck may be only few inches wide or could be 2, 3 or even more feet wide.

What if TV is outside the perimeter of said "deck" but still well within reach of someone standing in the tub?
 

mwm1752

Senior Member
Location
Aspen, Colo
I consider the deck as being inside the tub & more than not a receptacle is easily within reach from the tub to the receptacle outside of the deck - Free standing tubs are also makes difficult answers - how about a free standing tub(no shower) with 12" from 3 surrounding sides. Technically a receptacle on any of those walls is not in the tub - not much one can do if the tv is just outside the tub deck except gfi protection as I would assume the recept would be within 6" of tub.
 

kwired

Electron manager
Location
NE Nebraska
I consider the deck as being inside the tub & more than not a receptacle is easily within reach from the tub to the receptacle outside of the deck - Free standing tubs are also makes difficult answers - how about a free standing tub(no shower) with 12" from 3 surrounding sides. Technically a receptacle on any of those walls is not in the tub - not much one can do if the tv is just outside the tub deck except gfi protection as I would assume the recept would be within 6" of tub.
Most all rules that pertain to distance from a sink, tub, pool, other similar things is usually to the actual inside "basin wall" or similar and doesn't matter how big of a lip, trim, etc. may exist.
 

Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
RCDs (Residual Current Detectors), which are the EU equivalent to GFCIs, have a trip threshold of 30mA and that is considered "non-lethal" everywhere but North America. We are just beginning to see them here now, but elsewhere in the world, "electric showers" are the norm, which is an instantaneous electric heating element ON the pipe feeding your shower nozzle. Those have to be protected by an RCD and they consider that safe.

Here, 30mA is considered "equipment protection", but our GFCIs (personnel protection) are required to trip at 5mA (at least 4, no more than 6), so 6 times LOWER than what everyone else considers non-lethal. We swim in pools where the electric light is right there with us, hot tubs with electric heating elements right there with us. They are all protected by GFCIs; having a TV on the wall is absolutely no different.

By the way, the risk has absolutely nothing to do with the tub or pipes being metal or not, SOMEWHERE that water is going to make contact with metal that is grounded.

I saw one of the stories about a girl electrocuted "by her cell phone charger" in the bathtub; the detail often left out of that story but mentioned in some versions is that she did NOT use the GFCI protected receptacle in the bathroom, she put her charger on a long extention cord going into another room. The entire end of the cord, WITH the charger, is what fell into the tub with her.
 

kwired

Electron manager
Location
NE Nebraska
RCDs (Residual Current Detectors), which are the EU equivalent to GFCIs, have a trip threshold of 30mA and that is considered "non-lethal" everywhere but North America. We are just beginning to see them here now, but elsewhere in the world, "electric showers" are the norm, which is an instantaneous electric heating element ON the pipe feeding your shower nozzle. Those have to be protected by an RCD and they consider that safe.

Here, 30mA is considered "equipment protection", but our GFCIs (personnel protection) are required to trip at 5mA (at least 4, no more than 6), so 6 times LOWER than what everyone else considers non-lethal. We swim in pools where the electric light is right there with us, hot tubs with electric heating elements right there with us. They are all protected by GFCIs; having a TV on the wall is absolutely no different.

By the way, the risk has absolutely nothing to do with the tub or pipes being metal or not, SOMEWHERE that water is going to make contact with metal that is grounded.

I saw one of the stories about a girl electrocuted "by her cell phone charger" in the bathtub; the detail often left out of that story but mentioned in some versions is that she did NOT use the GFCI protected receptacle in the bathroom, she put her charger on a long extention cord going into another room. The entire end of the cord, WITH the charger, is what fell into the tub with her.
Quite frankly I am not extremely concerned about needing 30mA protection on the "electric shower" if one can assure the EGC will remain intact. Though 30 mA is still a good idea, would most likely trip if an element failed or begins to fail. We don't use GFCI or GFPE on typical storage tank water heaters and I don't think there is much for incidents with those either. Seen many with failed lower element that goes on for some time before getting called to fix it. That situation is probably about the greatest any risk might become with those.
 

mwm1752

Senior Member
Location
Aspen, Colo
Most all rules that pertain to distance from a sink, tub, pool, other similar things is usually to the actual inside "basin wall" or similar and doesn't matter how big of a lip, trim, etc. may exist.

& I would say those rules are specific to the inside where water is located - the tub has no distinction, so, interpretation is required - the knife edge line has to be established some how.
 
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