Clarification on bonding of interior water piping

[Steelhead]

I have a situation where there was a large section of metallic water piping removed about ten feet from the water line point of entrance to the dwelling and replaced with CPVC. There are two grounding electrodes installed outside. I plan to bond to the metallic water line where it enters the dwelling, but what about the sections of metallic piping that are isolated by the CPVC piping? Can I/should I bond to each isolated section of metallic water piping and then to the bonding conductor that runs to the incoming water line? That way I would only have to run one bonding conductor to the panel instead of multiple conductors. Could I have a code reference? Can't seem to find where this is permissible or not.

 

[Little Bill]

I have a situation where there was a large section of metallic water piping removed about ten feet from the water line point of entrance to the dwelling and replaced with CPVC. There are two grounding electrodes installed outside. I plan to bond to the metallic water line where it enters the dwelling, but what about the sections of metallic piping that are isolated by the CPVC piping? Can I/should I bond to each isolated section of metallic water piping and then to the bonding conductor that runs to the incoming water line? That way I would only have to run one bonding conductor to the panel instead of multiple conductors. Could I have a code reference? Can't seem to find where this is permissible or not.

If I understand you right, the CPVC was installed before it entered the building. If you have 10' still in contact with the earth, then it is still considered an electrode and would need to be connected to the other electrodes. If less than 10' then you could just bond to that if the rest of the interior pipes are metal, but the outside portion is not an electrode if less than 10'.
250.52 and also look at 250.53(D)

 

[Steelhead]

All the water lines in the dwelling are metallic except a medium sized chunk of CPVC in the middle. The water line entering the dwelling is metallic, I plan to bond to that. Then there is the CPVC chunk that isolates or separates the rest of the metallic piping. Do I also have to bond the isolated section of piping?

The other question I had is can I connect bonding jumpers (I will need about three jumpers) from the isolated sections of metallic piping together to one bonding conductor and then to the panel? If I can by code do it this way the result will be one bonding jumper connected to the metallic portions (of which there are several) of water piping and one GEC connected to the two GEs outside. These of course would terminate to the neutral bus in the service panel. Otherwise I would have to run a separate bonding jumper to each section of isolated water line. That would be a lot of extra wire and terminals needed in the panel of which there may not be enough.

 

[Gregg Harris]

All the water lines in the dwelling are metallic except a medium sized chunk of CPVC in the middle. The water line entering the dwelling is metallic, I plan to bond to that. Then there is the CPVC chunk that isolates or separates the rest of the metallic piping. Do I also have to bond the isolated section of piping?

The other question I had is can I connect bonding jumpers (I will need about three jumpers) from the isolated sections of metallic piping together to one bonding conductor and then to the panel? If I can by code do it this way the result will be one bonding jumper connected to the metallic portions (of which there are several) of water piping and one GEC connected to the two GEs outside. These of course would terminate to the neutral bus in the service panel. Otherwise I would have to run a separate bonding jumper to each section of isolated water line. That would be a lot of extra wire and terminals needed in the panel of which there may not be enough.

Bond it at the entrance where it is copper within 5' of where it enters "required" Then you can bond across the isolated section back to options;

250.52 Grounding Electrodes. (A) Electrodes Permitted for Grounding.


(1) Metal Underground Water Pipe. A metal underground water pipe in direct contact with the earth for 3.0 m (10 ft) or more (including any metal well casing bonded to the pipe) and electrically continuous (or made electrically continuous by bonding around insulating joints or insulating pipe) to the points of connection of the grounding electrode conductor and the bonding conductor(s) or jumper(s), if installed.

(2) Supplemental Electrode Required. A metal underground water pipe shall be supplemented by an additional electrode of a type specified in 250.52(A)(2) through (A)(8). If the supplemental electrode is of the rod, pipe, or plate type, it shall comply with 250.53(A). The supplemental electrode shall be bonded to one of the following: (1)

Grounding electrode conductor


(2)

Grounded service-entrance conductor


(3)

Nonflexible grounded service raceway


4)

Any grounded service enclosure


(5)

As provided by 250.32(B)


Exception: The supplemental electrode shall be permitted to be bonded to the interior metal water piping at any convenient point as specified in 250.68(C)(1), Exception.



250.104 Bonding of Piping Systems and Exposed Structural Steel. See related (A) Metal Water Piping. The metal water piping system shall be bonded as required in (A)(1), (A)(2), or (A)(3) 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).