2

If I have two sections of copper pipe (water or gas) connected by a push-to-connect fitting (e.g. Shark Bite brand's push-to-connect pipe fittings), is electrical continuity preserved, or do I need to do something extra such as bonding jumpers over every tee or union to maintain electrical continuity for the purposes of grounding/bonding?

For clarity, I am not referring to using either water or gas piping systems as a grounding electrode, but rather NEC 250.104 (quoted below from the 2014 NEC):

250.104 Bonding of Piping Systems and Exposed Structural Metal.

(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).

(2) Buildings of Multiple Occupancy. In buildings of multiple occupancy where the metal water piping system(s) installed in or attached to a building or structure for the individual occupancies is metallically isolated from all other occupancies by use of nonmetallic water piping, the metal water piping system(s) for each occupancy shall be permitted to be bonded to the equipment grounding terminal of the switchgear, switchboard, or panelboard enclosure (other than service equipment) supplying that occupancy. The bonding jumper shall be sized in accordance with Table 250.122, based on the rating of the overcurrent protective device for the circuit supplying the occupancy.

(3) Multiple Buildings or Structures Supplied by a Feeder(s) or Branch Circuit(s). The metal water piping system(s) installed in or attached to a building or structure shall be bonded to the building or structure disconnecting means enclosure where located at the building or structure, to the equipment grounding conductor run with the supply conductors, or to the one or more grounding electrodes used. The bonding jumper(s) shall be sized in accordance with 250.66, based on the size of the feeder or branchcircuit conductors that supply the building or structure. The bonding jumper shall not be required to be larger than the largest ungrounded feeder or branch-circuit conductor supplying the building or structure.

(B) Other Metal Piping. If installed in, or attached to, a building or structure, a metal piping system(s), including gas piping, that is likely to become energized shall be bonded to any of the following:

(1) Equipment grounding conductor for the circuit that is likely to energize the piping system

(2) Service equipment enclosure

(3) Grounded conductor at the service

(4) Grounding electrode conductor, if of sufficient size

(5) One or more grounding electrodes used

The bonding conductor(s) or jumper(s) shall be sized in accordance with 250.122, using the rating of the circuit that is likely to energize the piping system(s). The points of attachment of the bonding jumper(s) shall be accessible. Informational Note No. 1: Bonding all piping and metal air ducts within the premises will provide additional safety. Informational Note No. 2: Additional information for gas piping systems can be found in Section 7.13 of NFPA 54- 2012, National Fuel Gas Code.

(C) Structural Metal. Exposed structural metal that is interconnected to form a metal building frame and is not intentionally grounded or bonded and is likely to become energized shall be bonded to the service equipment enclosure; the grounded conductor at the service; the disconnecting means for buildings or structures supplied by a feeder or branch circuit; the grounding electrode conductor, if of sufficient size; or to one or more grounding electrodes used. The bonding jumper(s) shall be sized in accordance with Table 250.66 and installed in accordance with 250.64(A), (B), and (E). The points of attachment of the bonding jumper( s) shall be accessible unless installed in compliance with 250.68(A), Exception No. 2.

(D) Separately Derived Systems. Metal water piping systems and structural metal that is interconnected to form a building frame shall be bonded to separately derived systems in accordance with (D)(1) through (D)(3).

(1) Metal Water Piping System(s). The grounded conductor of each separately derived system shall be bonded to the nearest available point of the metal water piping system(s) in the area served by each separately derived system. This connection shall be made at the same point on the separately derived system where the grounding electrode conductor is connected. Each bonding jumper shall be sized in accordance with Table 250.66 based on the largest ungrounded conductor of the separately derived system.

Exception No. 1: A separate bonding jumper to the metal water piping system shall not be required where the metal water piping system is used as the grounding electrode for the separately derived system and the water piping system is in the area served.

Exception No. 2: A separate water piping bonding jumper shall not be required where the metal frame of a building or structure is used as the grounding electrode for a separately derived system and is bonded to the metal water piping in the area served by the separately derived system.

(3) Common Grounding Electrode Conductor. Where a common grounding electrode conductor is installed for multiple separately derived systems as permitted by 250.30(A)(6), and exposed structural metal that is interconnected to form the building frame or interior metal piping exists in the area served by the separately derived system, the metal piping and the structural metal member shall be bonded to the common grounding electrode conductor in the area served by the separately derived system.

Exception: A separate bonding jumper from each derived system to metal water piping and to structural metal members shall not be required where the metal water piping and the structural metal members in the area served by the separately derived system are bonded to the common grounding electrode conductor.

2

According to the SharkBite® Installation Instructions (PDF), you have to install a jumper to "ensure proper grounding".

enter image description here

  • Does the water not count for electrical continuity for grounding and bonding purposes? – Hari Ganti Feb 7 '18 at 0:28
  • 1
    @HariGanti No, it does not. – Tester101 Feb 7 '18 at 14:18
0

Your question starts with NEC 250.52 Grounding electrodes (A) (1) Metal underground water pipe. It states that this can be used for water pipes in direct contact with the earth for 10 feet and must be electrically continuous. I personally do not like push fitting to be used in this situation and would like to see a bonding jumper, but remember this only has to be for 10'. On another personal note, I never liked the idea of grounding to a gas pipe period. Never have never will.

  • You might offer some reasoning for your final statement. I'm not sure how gas pipe is relevant, but it doesn't mean much without an explanation. – isherwood Jun 1 '17 at 14:01
  • I apologize, I am not asking about using the water piping as a grounding electrode, but rather the requirement to bond metal piping systems (refer to the reference in my updated question). Also, not sure why keeping all of your pipes at the same voltage grounded potential is more hazardous than potentially allowing your gas pipe to become energized and not give them a path to dissipate. – statueuphemism Jun 1 '17 at 14:27
  • @statueuphemism - On the first part of your comment, you do need to bond the push in connections, but code minimum says it only has to be for 10'. If you want to make it longer for a better quality ground that's even better. – Retired Master Electrician Jun 1 '17 at 18:37
  • 1
    To all - I knew when I posted the gas line comment I might get this question. My answer is simple, but there is more than one reason from an engineering aspect why I don't like it and I am not going to go into that right now. The simple answer is, when I was in apprenticeship training in the late 1960's. Grounding to a gas pipe was a "grounding method of last resort". It appears electricity, volatile gas, arcing and heat were not a good idea. I was taught that way and no one has ever convinced me otherwise. – Retired Master Electrician Jun 1 '17 at 18:50
  • @RetiredMasterElectrician That's precisely the point, per the American Gas Association: "Bonding is provided primarily to prevent a possible electric shock hazard for persons coming into contact with the gas piping and other metal objects that are connected to the grounding system, but which may be energized at a different level of electrical potential. Gas piping can become energized by an electrical fault in the branch circuit of a gas appliance connected to the piping system. Nearby lightning strikes can also result in an unbalanced voltage build-up and " (continued in next comment) – statueuphemism Jun 2 '17 at 3:41

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.