Bonding with platic water pipe coming in

[binney]

Platic water lines coming in, majority of the house run in plastic. According to my boss we should bond the fisrt piece of copper we see, THE FIRST PIECE OF COPPER WE SEE . Even if it's just a 3" piece of copper that's completely isolated from the rest of the system, by plastic.

He feels as long as it's bonded in one spot the entire house is bonded. I disagree, I think that you need to bond each piece of copper, if necessary put in bonding jumpers. I am unable to find a code that's gives you a min. amout of copper that needs to be bonded, so i just go with my gut, if there a significant amount of copper I bond it (such as a manifold), if it's a little bit (an elbow or a stub out) I leave it.

Is there a right or wrong answer, if so what is it.

Thank you
Steve

 

[tom baker]

Re: Bonding with platic water pipe coming in

Its not clear that isolated copper stubs (for faucets, etc) need to be bonded per 250.104, in washington state we don't have to, unless the AHJ wants it. Its really up to the AHJ, check with them. There is not a big hazard if the pipe is isolated.

 

[iwire]

Re: Bonding with platic water pipe coming in

250.104 Bonding of Piping Systems and Exposed Structural Steel.

(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.

A piece of copper pipe here and there, even a manifold IMO can not be considered a metal water piping system

System: a regularly interacting or interdependent group of items forming a unified whole.

I also do not see the point of bonding an isolated section of metal pipe, after all the point of bonding the water piping system in the first place is to cause a short circuit if the system became energized, how is a small isolated piece of pipe going to become energized?

JMO, Bob

[ March 27, 2004, 12:22 PM: Message edited by: iwire ]

 

[sbe]

Re: Bonding with platic water pipe coming in

Gentlemen, Our local utility LIPA RED BOOK states the following: 7.1.7 Where a plastic water piping system is installed from the street line to the interior of the building, grounding shall be accomplished by (a)Installing two separate grounding conductors from the neutral block of the main switch to a supplemental ground, namely 2 driven ground rods. 7.1.4(b) Not less than two driven ground rods placed a minimum of 6 feet apart when a non-metallic water piping system exists or is to be installed. A separate grounding conductor to each ground rod shall be utilized. Of course it is advisable to consult with the AHJ and your local utility as to what they would accept. Hope this helps.

 

[hurk27]

Re: Bonding with platic water pipe coming in

By sbe: A separate grounding conductor to each ground rod shall be utilized.

Why separate conductor's? when the NEC only require's a #6.
And at 25 ohm's the highest current that could be drawen on this wire @ 120 volts is 4.8 amp's

And this came from you POCO.

 

[charlie]

Re: Bonding with platic water pipe coming in

I agree Wayne. The first thing I did when I became the secretary of our Electric Service and Meter Manual (Goldbook) Committee was to search through the book for situations where we were requiring the customer to violate the Code in order to get service. Remember that most of the people on these committees across the nation know the NESC but not the NEC. They are writing rules that are correct for the NESC and violate the NEC.

I recommend that you work with them to see if they will change the wording where the electric utility requires something that the NEC does not.

 

[sbe]

Re: Bonding with platic water pipe coming in

Gentlemen,
Please read 250.50. Lets apply a little common sense here, normally you would provide (x1) ground rod (the first grounding electrode) & (x1) metallic water pipe bond (the second grounding electrode), bond the service enclosure and in a commercial building you would also provide a third bond to the structural steel. If no metallic water pipe exists, then install the second ground rod as required. This will also provide some redundancy. We are all aware that the ground rods/electrodes only purpose in life is to shunt a lighting strike and to stabilize the voltage. The metallic water pipe, structural steel, etc. bonding requirements purpose is to provide an alternate fault current path that would be common through the house or building.
See 250.4(B)(4) & 250.53(B)(2).

 

[charlie]

Re: Bonding with platic water pipe coming in

It sounds like you are getting confused. The water piping system is always bonded to if it is a grounding electrode (it is required to bonded even if it is not an electrode). The water piping system is to be supplemented by one additional electrode. If the only electrode in the building was a concrete encased electrode, it would not have to be supplemented. The water pipe electrode is required to be supplemented by one additional electrode because of the possibility of loosing it with the use of plastic some time in the future.

The ground rod is the poorest and last you would go to. It is normally used in homes since they are of frame construction and another electrode is not available to use.

Bottom line, use the water pipe and supplement it with one additional electrode. If water is not available, install one electrode. This electrode is not required to be supplemented.

If I am not mistaken, in the lightning of the world (FL), a Ufer (concrete encased electrode) ground is required to be installed and used.