NECA Code question

1. Answer to Previous Code Question of the Day for Tuesday, March 13, 2012
Question:
Subject: Bonding of Gas Piping Systems
The bonding of gas piping systems which contain CSST to the grounding electrode system is
now mandatory in NJ.
The following Informational Notes are contained in the 2011 NEC.
250.104 Bonding of Piping Systems and Exposed Structural Steel
2011 Edition NATIONAL ELECTRICAL CODE 70–119
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- 2009, National Fuel Gas Code
Is Informational Note 1 really true given the possibility of turning the gas piping system in the
street into a neutral conductor as happens with water pipes which are part of the grounding
electrode system?
Thanks,
Tom Rorro
Electrical Inspector
Answer:
Underground gas piping systems are not permitted as grounding electrodes per NEC 250.52(B)
(1). NFPA 54 also prohibits this. Gas utilities typically isolate the underground portion of the
system from the above ground portions (in the buildings) using a dielectric fitting. Many gas
company regulations include this as a mandatory requirement. When an underground gas
piping system is on private property, the NEC requirements still apply, so the isolation must be
accomplished. Section 250.104(B) covers bonding requirements for metal piping systems,
including metal gas piping. Informational Note No. 1 is not a mandatory requirement.
Section: 250.52(B)(1)
AUTHOR: Charlie Trout
ANSWERS: Answers are the author’s opinions and do not represent formal interpretations of

2. the National Electrical Code.
All answers are based on the latest edition of the NEC, unless the question requests a
response based on a specific edition.
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ABOUT THE AUTHOR: Charlie Trout is a nationally-known NEC expert and author. He served
on three different National Electrical Code-Making Panels and is past chairman of CMP-12. He
is also a member of the NECA Codes & Standards Committee. In 2006 Charlie Trout won the
prestigious Coggeshall Award, given to recognize outstanding contributions to the electrical
contracting industry in the technical and training area.
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