Bonding metal water pipe

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soccerdude

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250.104 (A) Metal Water Piping, says the metal water piping system shall
be bonded as required. My question, is the hot water heater considered part of the "metal pipe system"? Or do I need to bond both the cold water pipe and the hot water pipe? Any help would be great> Thank you
 
Hot water heater(HWH) typically have a di-electric fitting as the nipple enters the tank. This di-electric is an (electrically) insulating material. The bond between hot and cold has been interuppted.

If has been debated - and probably will be again - that today's modern sinks, faucets, shower diverters, et al maintain that bond internally through their own construction.

I am of the opinion that a bonding jumper IS required at the HWH between the hot/cold pipes.

The commentary (uneforceable) following 250.104(A) in the 2005 NECH states:
Bonding the interior metal water piping system is not the same as using the metal water piping system as a grounding electrode. Bonding to the grounding electrode system places the bonded components at the same voltage level. For example, a current of 2000 amperes across 25 ft of 6 AWG copper conductor produces a voltage differential of approximately 26 volts. Section 250.104(A)(1) requires the interior metal water piping system and any other metal piping systems likely to become energized to be bonded to the service equipment or grounding electrode conductor.
If it cannot reasonably be concluded that the hot and cold water pipes are reliably interconnected, an electrical bonding jumper is required to ensure that this connection is made. Some judgment must be exercised for each installation. The special installation requirements provided in 250.64(A), (B), and (E) also apply to the water piping bonding jumper.
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Dennis Alwon said:
What about when the water pipe is used as a grounding electrode. 250.53 (D)(1)
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(1) Continuity. Continuity of the grounding path or the bonding connection to interior piping shall not rely on water meters or filtering devices and similar equipment.

If I am allowed I will rephrase this section;

Continuity of the path to the part of the metal water pipe that is underground up to five feet inside the structure or the connection to the bonding required in 250.104 can not depend on a DEVICE.
A water heater is an appliance and not a device.

What is the definition of grounding?
Grounding is the connection to earth.

The Grounding Electrode conductor can land on the first five feet of the water pipe and then all other electrode bonding jumpers can land on the water pipe. What is being said in (D)(1) is that the path to earth can not rely on devices such as meters or filters or other devices such as these.
It is also saying that the bonding requirement found in 250.104 can not depend on these types of devices either.

Somewhere around the nineties the requirement to make a metal water pipe electrically continuous was removed from Article 250. From then on the only requirement was to bond the metal water pipe at some accessible location.

This bonding around a water heater myth has lived on due to the old requirement to make the water pipe continuous in earlier editions of the NEC. There is no requirement to make a metal water piping electrically continuous to be found anywhere in today?s NEC.

 
Take a look at this thread.
Don
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Don thank you for the link I just read the whole thing, a great read.

Mike ,thank you for the understanable way you debate.

George(if your reading) , I thank you as well ,but I must say after all the reading and a bit of looking elsewhere ,I think Mike has the stronger argument , but I think your last post says it all .

I must say I have a love hate relation with this sight I love it the wife hates it :grin: :D

Now , enough of this arse kissing.
 
M.D., I appreciate you considering my opinion; even though you came to the same conclusion as Mike W. As long as I made myself understood, I'm happy. :)

For those that don't care to look at the other thread, I feel it's an interpretation call at this point, the wording is weak, IMO.
 
George , I did not say that I am in conclusion with Mike , I said his is the stronger position in the debate. The back up information of what was in the code and no longer is, the removal of the water pipe being used as the equipment ground along with the advent of plastic piping,& then the panel statements showing that they are aware of the question of isolated metal water piping ,and yet time and time again they point to 250.104(b). Purty stong stuff!
The debate will and ought to continue. Again, I thank you for giving me your views.
Marc.
 
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