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Joined: Aug 2003
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I don't see the term "likely to become energized" in 250.104(A).
Ryan Jackson,
Salt Lake City
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Abrasion of nonmetallic against the pipes (due to pressure from insulation)?
Rodents? Lightning strikes? Improperly grounded appliance?
It doesn’t seem all that impossible to me.
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Joined: Jul 2001
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Matt, don't forget to bond picture hanging nails also. They may be engergized when the NM is not in the center of the stud.
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Good Point!
: Goes to RadioShack to buy bags of alligator jumpers :
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Joined: Jul 2004
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And remember to properly bond the PEX with an unspliced length of 1/4" Nylon rope running from the ground bus in the service panel to a listed clamp on the PEX.
[This message has been edited by SolarPowered (edited 07-23-2005).]
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Joined: Jun 2005
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Hi Matt, about your concern, it does bear thinking about since the dangers of energized plumbing are many.
I fixed a problem for a camp owner years ago who was getting shocks while taking a shower. The drain had become live due to a chafed piece of old cloth type NM laying on the metal drain piping under the camp, and this was isolated from the shower walls and hot/cold pipes by the stone shower base. There was 110 volts on the drain grate and he got blasted when his foot was touching this and he touched the faucet handles.
I agree with the others that you have to be realistic in assessing the possibilities, however.
JBD, LOL, but you forgot the metal flush handle...if that is energized and you are grounded and you lean back...well, OUCH!
[This message has been edited by poorboy (edited 07-23-2005).]
[This message has been edited by poorboy (edited 07-23-2005).]
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Ryan J,
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.
From the Code CD rom.
The point of my question, was how could a water pipe become energized? I never figured a wire hanging on it, because they all should be strapped up and away from the water pipes.
But what still boggles me is on a well water system, with plastic incoming, and then a change over to metal, why size the bonding jumper for the size of the service? I always wondered how the service conductors could touch the water pipe, if they were no where near it.
I see the answer from poorboys post, I guess the wires could fall somewhere, somehow onto the water pipes.
And I guess the water heater somehow could fail, energizing the pipes.
Dnk....
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dnk, (A) Metal Water Piping. The metal water piping system shall be bonded as required in (1), (2), (3), or (4) of this section. The bonding jumper(s) shall be installed in accordance with 250.64(A), (B), and (E). The points of attachment of the bonding jumper(s) shall be accessible.
(1) General. Metal water piping system(s) installed in or attached to a building or structure shall be bonded to the service equipment enclosure, the grounded conductor at the service, the grounding electrode conductor where of sufficient size, or to the one or more grounding electrodes used. The bonding jumper(s) shall be sized in accordance with Table 250.66 except as permitted in 250.104(A)(2) and (A)(3). Ryan's point is that the code rule requires bonding for all metal water piping systems, not just those that are 'likely to become energized". Note that the words "likely to become energized" do not appear in the section that you cited. They do appear in 250.104(B) and (C) for other metal piping sytems and structural steel, but not in (A) for water piping systems. Don
Don(resqcapt19)
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That was my interpretation of the code, IF each network of copper pipe constitutes a “system”.
I thought it did.
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Don,
The section I posted was just "cut and Pasted" from the 2002 code Cd.
I didn't write it or reword it, it came word for word from the CD Rom, in the "explanation area".
Is the CD Rom wrong for stating this then?
Dnk...
(edited for spelling)
[This message has been edited by Dnkldorf (edited 07-23-2005).]
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Tom
Shinnston, WV USA
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