Tub space and receptacles

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dcspector said:
I had a phone call at the same time and had to run.
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Thanks for the clarification, and the apology is not necessary. I was puzzling over your response, is all. :smile: The compression of this medium sometimes leads to curious ambiguities.
 
Jim W in Tampa said:
Thanks Bob my mind was wondering about same type tub.
This is not about what most think is safe , it's about what NEC says. In a court of law anything that is not clear is simply thrown out and defendant wins. Most here do not like #1 but that does not matter. We are stuck with NEC, maybe we need to go after them for failure to write things to say what they mean. We are being ripped off. We pay for a book of laws and get garbage. Someone gets a big pay check for all this and we foot the bill. Maybe OBAMBA will get involved.
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Yes, ask the president, sometime law professor, and now all things to all people.:roll:
 
A common installation around here is that any box anywhere near the tub is on the load side of a GFCI including switches for anything, including general lighting, etc. I've done many of these myself.
 
iMuse97 said:
A common installation around here is that any box anywhere near the tub is on the load side of a GFCI including switches for anything, including general lighting, etc. I've done many of these myself.
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Thats a good and smart idea but problem is NEC does not require it. As much and often as we see NEC going too far ,sometimes they leave things out. The issue here is only about 1 thing and that is if picture #1 is legal as per NEC. Few here will say its safe. I am one of them ---holes that never want to see water,people,and electric mixed. Add alcohol and it gets real serious. As a night club owner/manager i see it far too often. Best we can do is install based on we are dealing with kids or ID 10 T people. Simply is no way i would ever install what is in #1 because i see past all the what if's. Let them get out an extention cord. If they do then i am not a party to it. We know better than the average home owner. Almost did something stupid few days ago. Truck battery dead and was going to plug charger in. Grass is always wet in morning in FL , almost did it barefoot but didnt. Yes outlet on GFI but really not wanting to test it that way. Even us crackers are smart sometimes.
 
al hildenbrand said:
Its not the potential, its the current. . . and, as you set up your hypothetical, there is no current path from the two-wire across the water, so, where is the other side of the "difference of potential"?
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There maybe a voltage "gradient" in the water and some current will be flowing in the water. A person in the water may "short circuit" this voltage gradient and cause current to flow across his body. It is my opinion that a wet body will be, in many cases, more conductive than the water itself and the amount of current that is flowing on the body may be enough to cause harm.
 
hurk27 said:
. . . if a two wire appliance was to fall into the water, and lets say we had a regular non-metal tub, plastic plumbing, no bonding to drain, fixtures or other, this two wire appliance could create a difference of potential in the water, and no GFCI in the world would ever trip to save the person in the same tub.

Why because the GFCI would only see a load between the hot and neutral of this appliance.
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al hildenbrand said:
Its not the potential, its the current. . . and, as you set up your hypothetical, there is no current path from the two-wire across the water, so, where is the other side of the "difference of potential"?
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don_resqcapt19 said:
There maybe a voltage "gradient" in the water and some current will be flowing in the water. A person in the water may "short circuit" this voltage gradient and cause current to flow across his body. It is my opinion that a wet body will be, in many cases, more conductive than the water itself and the amount of current that is flowing on the body may be enough to cause harm.
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I understand what you are describing, Don, and I, too, believe a wet body will be a good conductor.

However, for the scenario that Wayne paints, the first thing I don't see is the plane or point that is at any potential, or ground, in the surrounding water in the tub, other than that created by a "two wire appliance".

Isn't this going to be like a bird on a high tension wire? The bird is more conductive than the air around the bird, yet, even where the ground plane actually IS present in the earth below the high tension line, the currents that flow from capacitive and inductive coupling are so miniscule as to cause no discomfort to the bird.

The bird sits and delights in the sunset.

In Wayne's scenario, the closest references will seem to be the EGC, grounded conductor and hots of various circuits in unknown orientation to the tub, and possibly a metal HVAC ductwork system. Let's say those items are there, but some number of feet beyond the perimeter of this non-conductive envelope of a tub system holding the water, person and recently fallen two wire appliance.

Say the appliance is a toaster (maybe the bather likes toast and bath?). Other than sticking a hand into the toaster slot, and shorting out the current path with ones fingers, the current path being between the two points of contact on the one hand inside the toaster slot, what other current path can there be that would cause certain harm that wouldn't trip the GFCI?
 
electricmanscott said:
I agree with your call on both and would have no problem doing the installation.

I think we all know the alternative would be an extension cord run from the receptacle by the sink.
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As much as I hate it, I think this is a key point to consider.
If ms. homeowner wants a tv there, it will be there, and if an extension cord is needed, so be it. I abhor the installation, but am on the side that thinks it meets Code and is at least safer than a cord draped to the sink.
 
al hildenbrand said:
I understand what you are describing, Don, and I, too, believe a wet body will be a good conductor.

However, for the scenario that Wayne paints, the first thing I don't see is the plane or point that is at any potential, or ground, in the surrounding water in the tub, other than that created by a "two wire appliance".

Isn't this going to be like a bird on a high tension wire? The bird is more conductive than the air around the bird, yet, even where the ground plane actually IS present in the earth below the high tension line, the currents that flow from capacitive and inductive coupling are so miniscule as to cause no discomfort to the bird.

The bird sits and delights in the sunset.

In Wayne's scenario, the closest references will seem to be the EGC, grounded conductor and hots of various circuits in unknown orientation to the tub, and possibly a metal HVAC ductwork system. Let's say those items are there, but some number of feet beyond the perimeter of this non-conductive envelope of a tub system holding the water, person and recently fallen two wire appliance.

Say the appliance is a toaster (maybe the bather likes toast and bath?). Other than sticking a hand into the toaster slot, and shorting out the current path with ones fingers, the current path being between the two points of contact on the one hand inside the toaster slot, what other current path can there be that would cause certain harm that wouldn't trip the GFCI?
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The water is much more conductive than is the air and that is the difference between the bird on the wire and the person in the water.

I believe there will be current between the ungrounded and grounded conductor in the water and that this current will take all of the available paths in the water. To me this means that the current will flow on water that is not directly between the two conductors. The person will short out some of these paths and there will be current flow on the persons body. I don't know if there will be enough current to be a problem, but I expect in some cases there would be a shock hazard.

As far as the GFCI tripping, if the device in the water only has a two wire cord and all of the plumbing is non-metallic, there may not be any path for current that would trip the GFCI, but there still may be a path that could cause a person harm.
 
Al
I have seen a demonstration a long time ago where a chemical was used to show current flowing in water, I have no idea what was used but it would change color any place there was current, if I remember right it was a work shop about pool safety.

When a lamp cord was dropped into the plastic bucket of water, the water around the ends of the wire had a foot ball looking red around it between the two conductors, it reminded me of the lines of magnet lines of iron dust between the north and south pole of a magnet.
They were not just in a straight line between the conductors but belly-ed out like a foot ball.

What brought this up was a MH video on stray currents, that showed a hair dryer in a insulated sink running all the while plugged into a GFCI, he also stated the same, that the GFCI could not protect a person in this case, I agree the likely hood of an electrocution in this case would not be very great, but it could happen.
The water in the tub with soap in it would or could be a very good conductor, the space between the grounded and un-grounded conductor termination points could be far enough apart that some of the current could flow outside the appliance, think about a hair dryer, the hot goes into the handle and stops at the switch in the handle, while the grounded conductor runs all the way up to the motor and heater at the other end, I could see where some of the current could flow between the switch and the heater end and as these are shaped like a gun, this would allow current to flow across the outside.
If a person were to instinctively grab the handle they would be right in the middle of the current flow, while across one hand would not be across the heart, but it could disable an elderly person from getting out of the tub?

As Don pointed out, the demonstration I saw, did show current gradient's away from the straight line between the two difference of potential.

Sorry I didn't respond before as my keyboard got wet, had to get a new one:mad:
 
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Thanks, Don & Wayne for the thoughtful replies. I'm cogitatin' on 'em.

Meat Space has me somewhat distracted.

The cross-appendage vs. cross-torso current path probability is the thrust of my discussion.
 
(C) Bathtub and Shower Space. Receptacles shall not be
installed within or directly over a bathtub or shower stall.

While I dont like it.....in the original OP's images you do not have a violation. The receptacle inside the cove is not within or directly over a bathtub or shower stall as it has been defined. While I do not like the application and I would not install it there, nothing in the NEC that would prohibit it as it is written right now.

Now...move to Canada and you got a problem however.
 
What about the intent of the Code?

What about the intent of the Code?

While the language of the Code may not specifically disallow this installation, it is apparant the 'within arms reach' creates a hazard.

I could possibly see an installation where the receptacle is out of reach or the TV is permanantly mounted where access to the receptacle is only possible by dismounting the TV.

As an engineer, I have to err on the side of safety supporting the intent of the Code.
 
Good call Chris,.. I'll bet the hardest part was not imposing your own personal view..... I just wish they had a few non GFCI protected wall lights in the stall to make it interesting :)
 
Post 78 pretty well gives my reading of the situation.

There are _two_ different types of prohibited spaces; over a 'tub' or inside a 'shower stall'. In some bathrooms you only have tubs, in some bathrooms you only have shower stalls, but in many you have a tub with a shower head above. To my mind, if you have a shower head present, then the tub, along with the walls contiguous with the space above the tub, and any shelves, alcoves, or counters that contiguous with the space above the tub form a 'shower stall'.

Thus my opinion is that the receptacle in question is not in the tub space, but _might_ be in the 'shower stall' space, depending upon unknown mechanical details (is there a shower head, is there a divider?).

For what its worth, we've had discussions in the past about how to safely install a television nook above a tub. Approaches included having the TV behind glass, controlled by a remote.

IMHO an inspector should be able to say when they feel something is a bad idea, as long as it is clear that their _opinion_ has as much legal weight as an FPN. As long as it is about mutually respectful learning, and not power trips.....

-Jon
 
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