Why does code note require gfci breakers on electric water heaters? - Contractor Talk - Professional Construction and Remodeling Forum

bob_cntrctr · 09-27-2009, 03:21 PM

Riddle me this:

We require gfci outlets when electricity is available within 3-feet of water, so why don't electric water heaters, where an electric element is permanently and fully immersed in water, require gfci breakers?

bwalley · 09-27-2009, 03:23 PM

Quote:

Originally Posted by bob_cntrctr

Riddle me this:

We require gfci outlets when electricity is available within 3-feet of water, so why don't electric water heaters, where an electric element is permanently and fully immersed in water, require gfci breakers?

I have never heard of a case where an electric water heater failing has electrocuted anyone, but you do have a good point.

480sparky · 09-27-2009, 03:42 PM

How often does someone complete an electrical circuit between a water heater and ground?

The difference between the electricity available in your kitchen or bathroom is that you are plugging something into a receptacle. And what you plug in may or may not have a fault in it. If it does, the GFI will detect that fault and disconnect power.

If the heating elements are in direct contact with the water, then would not that create a ground fault and trip the breaker? Then you would only have a large water storage tank.

I think you're trying to apply the old-wives' tale of "Electricity and water don't mix" to an appliance that contains water and has electricity suplied tot it. But what about the ice maker in your fridge? Your garbage disposal in the sink? Your washing machine? Dishwasher? Aren't all these items connected to both water and electricity? Do you GFI them?

bob_cntrctr · 09-27-2009, 05:30 PM

Sparky,

I'm just sayin' I'm not sure I see the difference between a blown insulator on a water heater element and a hair dryer in the bathtub.

As for the rest of those appliance, you're generally not standing in the water of your dishwasher to be the link that completes the circuit, no?

480sparky · 09-27-2009, 06:00 PM

Quote:

Originally Posted by bob_cntrctr

Sparky,

I'm just sayin' I'm not sure I see the difference between a blown insulator on a water heater element and a hair dryer in the bathtub.

As for the rest of those appliance, you're generally not standing in the water of your dishwasher to be the link that completes the circuit, no?

The difference between the water heater element and the hairdryer in the bathtub is with the hairdryer, it is easily to become part of the circuit between it and ground. How often does a person, under ordinary, every-day circumstances, get near anything electrical that's sealed inside a water heater when it is energized? Just as often as all the other appliances I listed.

If you're not standing in water when you're operating your dishwasher, garbage disposal, fridge or washing machine, then you're probably not the type that will be standing in water when you're operating your water heater.

Speedy Petey · 09-27-2009, 06:22 PM

Quote:

Originally Posted by bob_cntrctr

We require gfci outlets when electricity is available within 3-feet of water,...

Who requires this?

bob_cntrctr · 09-27-2009, 06:33 PM

Quote:

Originally Posted by 480sparky

How often does a person, under ordinary, every-day circumstances, get near anything electrical that's sealed inside a water heater when it is energized?

Everytime you wash your hands under running warm water or take a shower, there's a direct line of water between you and the heating element.

Think of it like this - would you do this? : put a hair dryer in a plastic bag and plug it in and turn it on. Now put it and your hands under the water running out of the bathroom sink tap. Same thing. You're depending on the platsic bag, or the heater element jacket, to keep the electrical part out of the water your hands are in. No?

480sparky · 09-27-2009, 06:50 PM

Quote:

Originally Posted by bob_cntrctr

Everytime you wash your hands under running warm water or take a shower, there's a direct line of water between you and the heating element.

Think of it like this - would you do this? : put a hair dryer in a plastic bag and plug it in and turn it on. Now put it and your hands under the water running out of the bathroom sink tap. Same thing. You're depending on the platsic bag, or the heater element jacket, to keep the electrical part out of the water your hands are in. No?

So you're saying it's possible for electricity to travel fom your water heater, through the pipes, out the faucet, down the stream of water, through you, then.......... where?

The difference between the hair dryer and your water heater is that the hair dryer is SEPERATED from a potential ground source (usually the pipes that carry the water). And if the hair dryer has a fault in it, YOU become a potential circuit. But a water heater has both the source of electricity and a ground within the same enclosure, so electricity isn't going to travel up the pipes and into your bathroom and to the faucet and through the water, then through you, and then back to the water heater through the pipe. A single pipe cannot be the supply and return path for the electricity any more than a single conductor can supply the hair dryer and provide a return path.

Of course, this is assuming a metal plumbing system such as copper or galvanized pipe. Pex systems are basically plastic, and therefore are insulators. And water isn't really a good conductor either.

Speedy Petey · 09-27-2009, 06:51 PM

Quote:

Originally Posted by bob_cntrctr

Everytime you wash your hands under running warm water or take a shower, there's a direct line of water between you and the heating element.

I truly hope you are not implying that the water will conduct electricity that far.

Speedy Petey · 09-27-2009, 06:52 PM

Quote:

Originally Posted by bob_cntrctr

Think of it like this - would you do this? : put a hair dryer in a plastic bag and plug it in and turn it on. Now put it and your hands under the water running out of the bathroom sink tap. Same thing. You're depending on the platsic bag, or the heater element jacket, to keep the electrical part out of the water your hands are in. No?

I am really not sure why, but you are looking for a problem where NONE exists.

protechplumbing · 09-27-2009, 07:31 PM

I have.

Quote:

Originally Posted by bwalley

I have never heard of a case where an electric water heater failing has electrocuted anyone, but you do have a good point.

480sparky · 09-27-2009, 07:35 PM

Quote:

Originally Posted by protechplumbing

I have.

"Details, Bob..... details!"
------George Malley (John Travolta) to Dr. Bob Neidorf (Brent Spiner), Phenomenon, 1996

protechplumbing · 09-27-2009, 07:40 PM

Top element was shorted out. Neither the heater nor the water distribution system was grounded. Guy touched the shower valve and got juiced with 120v. He was ok though.

480sparky · 09-27-2009, 07:41 PM

Quote:

Originally Posted by protechplumbing

Top element was shorted out. Neither the heater nor the water distribution system was grounded. Guy touched the shower valve and got juiced with 120v. He was ok though.

Then he was not electrocuted.

protechplumbing · 09-27-2009, 07:53 PM

Well, he felt electricity flowing thru his body and there was in fact voltage present at the valve. How do you figure that he wasn't?

Celtic · 09-27-2009, 07:57 PM

Quote:

Originally Posted by protechplumbing

Well, he felt electricity flowing thru his body and there was in fact voltage present at the valve. How do you figure that he wasn't?

When a person is "electrocuted" - they are dead.

protechplumbing · 09-27-2009, 08:05 PM

I was always under then impression that electrocution is when someone has electricity from flowing threw their body at a sufficient voltage and current to cause discomfort. If your definition is the correct one then when it is stated on the news that "a man died from electrocution" it is somewhat of a redundant statement no?

protechplumbing · 09-27-2009, 08:08 PM

I just looked it up and you are correct.

Let me correct my former statement: He was shocked when he grabbed the shower valve, he was ok though.

480sparky · 09-27-2009, 08:10 PM

Quote:

Originally Posted by protechplumbing

I was always under then impression that electrocution is when someone has electricity from flowing threw their body at a sufficient voltage and current to cause discomfort. If your definition is the correct one then when it is stated on the news that "a man died from electrocution" it is somewhat of a redundant statement no?

If you have electric current flowing through your body, you are experiencing electrical shock. If it is powerful enough, it kills you and the medical examiner puts electrocution on your death certificate.

I don't recall anyone on death row being put in the chair and 'shocked' to death.

Celtic · 09-27-2009, 08:16 PM

Quote:

Originally Posted by protechplumbing

I was always under then impression that electrocution is when someone has electricity from flowing threw their body at a sufficient voltage and current to cause discomfort. If your definition is the correct one then when it is stated on the news that "a man died from electrocution" it is somewhat of a redundant statement no?

Do you see the flaw in your post?

The "media" are not the experts.....what's tom'row's weather gonna be

Do you see my point?

Here is quickee definition from wiki [feel free to check other sources if you wish]:
http://en.wikipedia.org/wiki/Electric_shock

Quote:

An electric shock can occur upon contact of a human body with any source of voltage high enough to cause sufficient current through the muscles or hair. The minimum current a human can feel is thought to be about 1 milliampere (mA). The current may cause tissue damage or fibrillation if it is sufficiently high. Death caused by an electric shock is referred to as electrocution. Generally, currents approaching 100 mA are lethal if they pass through sensitive portions of the body.

This little graphic also helps to illustrate the point [and common misconception]:

http://engineering.dartmouth.edu/msh...afetelec.shtml

In the graphic, you will notice the word "electrocution" has been omitted - by error or design I do not know. You will see the words:
Severe Shock
Death

Clearly, there is measurable difference between these words.

Clearer?