For this reason bonding by means of the equipment grounding conductor run to the appliance does not meet the requirement of bonding metal gas piping “to the grounding electrode system.” Removal of the appliance would eliminate the bonding of the entire gas piping system. The gas piping system is undoubtedly grounded by means of the equipment grounding conductor connected to the gas appliance, but how can we say the requirements of Section 250-104(b) are satisfied? This section clearly requires that the metal gas piping be “electrically continuous and bonded to the grounding electrode system.” Relying on an appliance to ensure electrical continuity is incorrect. QUESTION: When I connect the gas piping to my clothes dryer or to any other grounded gas-fired appliance with electrical components, isn’t the metal gas piping system in the building automatically grounded and the requirements of Section 250-104(b) satisfied?ĪNSWER: Many people believe that, but I am not one of them. It may be difficult to pinpoint which circuit(s) have the potential to energize a metal gas pipe run through a building. It may be run on the outside as well as the inside of the building, and its exposure to lightning would require it to be sized according to Section 250-66. My opinion is that metal gas piping is not included in Section 250-104(c) for other reasons. There is some argument regarding the use of Section 250-104(c), which requires other interior metal piping to be bonded in accordance with Table 250-122, based on the rating of the circuit that may accidentally energize the piping. Section 250-104(b) requires that the bonding be to the grounding electrode system, which I consider also to mean in accordance with Section 250-66. I understand that as meaning that the sizing should be done according to Section 250-66. QUESTION: How do I size the bonding jumper used to bond metal gas piping?ĪNSWER: Section 250-2(c) requires the bonding to be to the supply system grounded conductor. The following questions and answers should clarify what many readers are asking. Judging by the responses to NECA’s online “Code Question of the Day (CQD),” gas piping and its use in bonding and grounding sure generated controversy and explosive comentary.

Outside gas line code