I am trying to determine if it is acceptable to bond a gas line to the water pipes in a home. Most discussions about this seem to state the ground from the gas pipe has to go to a grounding rod system or the supply system grounded conductor. Just not sure what this means. So water pipes can never be used–correct? Can someone clarify this for me. Thanks
Depends… need more info about the systems.
Start with… “What material is the water service piping made out of, and is it a public water service or private?”
"This American Gas Association fact sheet provides an overview of the requirements for the electrical bonding of fuel gas piping ".
7.13.1 Pipe and Tubing other than CSST. Each aboveground
portion of a gas piping system other than CSST that is likely to
become energized shall be electrically continuous and bonded to
an effective ground-fault current path. Gas piping other than
CSST shall be considered to be bonded when it is connected to
appliances that are connected to the appliance grounding
conductor of the circuit supplying that appliance…
1… your link is no good… member only.
2… care to finish what your copy&paste left off?
3… bonding to a water system where the service entrance pipe is plastic, is useless and does not constitute a ‘bond’.
4… if any part of a copper water supply system has been replaced with plastic components, a once bonded system may now be compromised, and should be deferred to a sparky for testing and correcting.
Try this link.
If that don’t work see attached.
I guess I’m a member because it works for me.
The home would have copper water lines and is a municipal system. I just want to make sure bonding from a gas line to a copper water line is acceptable. Sometimes the code does speak in simplistic terms. Thanks so much for your input…it’s really appreciated
How about this
FACT SHEET
ELECTRICAL BONDING OF GAS PIPING SYSTEMSrev.1-7-15
This American Gas Association fact sheet provides an overview of the requirements for the electrical bonding of fuel gas piping systems to the electrical grounding system based on ANSI Z223.1/NFPA 54, National Fuel Gas Code - 2015 (NFGC). The bonding requirements in previous code editions, in local jurisdictions or in specific situations, may differ.
This fact sheet is not intended to replace knowledge of applicable local and national codes or address specific situations. The user should consult a competent professional and be thoroughly familiar with all applicable local codes, specific manufacturer’s installation instructions and the National Electrical Code (NEC®)1 before attempting to bond any fuel-gas installation.
WHAT IS AN ELECTRICAL BOND
An electrical bond is an intentionally installed electrically conductive and continuous path from the gas piping to the grounding electrode system.
WHY BOND GAS PIPING?
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 a resulting high electrical potential difference. That potential can cause an electrical arc between the gas piping and another nearby metallic system such as the copper water piping or electric wiring or structural steel. The arc may cause damage to certain gas tubing systems.
NFGC REQUIREMENTS2
The NFGC requires bonding to help reduce possible electric shock hazard and potential tubing damage. The specific requirements in the 2015 NFGC are contained in Section 7.13 as follows:
7.13 Electrical Bonding and Grounding.3
7.13.1 Pipe and Tubing other than CSST. Each aboveground portion of a gas piping system other than CSST that is likely to become energized shall be electrically continuous and bonded to an effective ground-fault current path. Gas piping other than CSST shall be considered to be bonded when it is connected to
1NEC and National Electrical Code are registered trademarks of the National Fire Protection Association.
2 The 2015 Editions of the International Fuel Gas Code contain extracts of the same bonding requirements.
3 © 2015 NFPA/AGA
appliances that are connected to the appliance grounding conductor of the circuit supplying that appliance.
7.13.2 * CSST. CSST gas piping systems and gas piping systems containing one or more segments of CSST, shall be bonded to the electrical service grounding electrode system or where provided, lightning protection grounding electrode system.
7.13.2.1 The bonding jumper shall connect to a metallic pipe, pipe fitting, or CSST fitting.
7.13.2.2 The bonding jumper shall not be smaller than 6 AWG copper wire or equivalent.
7.13.2.3 The length of the jumper between the connection to the gas piping system and the grounding electrode system shall not exceed 75 ft (22 m). Any additional electrodes shall be bonded to the electrical service grounding electrode system or where provided, lightning protection grounding electrode system.
7.13.2.4 Bonding connections shall be in accordance with NFPA 70, National Electrical Code®.
7.13.2.5 Devices used for the bonding connection shall be listed for the application in accordance with UL 467, Grounding and Bonding Equipment.
7.13.3* Prohibited Use. Gas piping shall not be used as a grounding conductor or electrode.
7.13.4* Lighting Protection System. Where a lightning protection system is installed, the bonding of the gas piping shall be in accordance with NFPA 780, Standard for the Installation of Lightning Protection Systems, 2008.
GAS PIPING BONDING METHODS
The NFGC bonding methods can utilize the appliance grounding conductor (the third or grounding wire) of any connected appliance, or it can be made using a direct bond. A direct bond consists of a listed grounding clamp and separate conductor run from the gas piping to the grounding electrode system. The 2015 NFGC requires a direct bond whenever Corrugated Stainless Steel Tubing (CSST) gas piping is installed.
Appliance Grounding Conductor for Other Than CSST: NFGCsection 7.13.1 specifies when and how the bonding of gas piping other than CSST is to undertaken. When a gas appliance has an electrical connection, that appliance may energize the gas piping system, and a bond is required. The NFGC does not require gas piping other than CSST to be bonded where there are no electrically connected appliances on the system.
The appliance grounding conductor for the circuit that is likely to energize the piping is considered sufficient to meet the bonding requirement for gas piping other than CSST. This type of bond provides an effective, low-impedance, electrically conductive current path to the over-current protective device (typically the circuit breaker), and is designed to protect people from ground faults within the
Copyright© 2015 – American Gas Association - All rights reserved Page 1
electrical system. The bonding conductor is sized based on
the electrical power requirements of the appliance branch
circuit. The NFGC and the appliance manufacturer’s
instructions require that the appliance’s grounding conductor
be installed and sized in accordance with the National
Electric Code and Table 250.122.
Direct Bonding: NFGC Section 7.13.2 requires all CSST to
be directly bonded using a properly sized conductor. A
direct bond may also be used for gas piping other than CSST.
The conductor is to be connected to the grounding electrode
system, options include:
• Electrical service enclosure, or
• Grounded conductor at the electrical service, or
• Grounding electrode conductor, or
• Any installed grounding electrode.
The bond is achieved by attaching a conductor from a
segment of rigid gas pipe or CSST fitting to any one of the
options listed. The conductor length is limited to a
maximum of 75 ft. A clamp listed to UL 467 is required and
can be installed anywhere on the gas piping system. For
CSST systems, this bond is intended to provide a means to
minimize the difference in voltage level between the CSST
and other metallic systems in close proximity caused by a
line surge or imposed by an indirect lightning strike. NEC®
Table 250.66 contains the minimum size for the bonding
conductor which may be larger than the NFGC’s minimum
requirement of 6 AWG. The NEC’s specified bonding
conductor size should be installed; however, the conductor
may not be smaller than a 6 AWG copper wire. NEC®
Section 250.70 describes the various methods for making this
connection.
The option of bonding to any installed electrode is contingent
on the additional electrodes being bonded to the electrical
service grounding electrode system or where provided,
lightning protection grounding electrode system.
Where a lightning protection system is installed the bonding
of gas piping must be in accordance with NFPA 780.
The direct bonding of CSST systems is required regardless of
the type of appliances connected and is in addition to the
bonding that results from the use of the appliance grounding
conductor on electrically powered gas appliances.
OTHER BONDING CONSIDERATIONS
Regardless of the bonding method selected, the gas piping
system must be electrically continuous in order to bond an
entire piping system from a single point. Metal pipe and
tubing joints that are threaded (including those using joint
compounds), flanged, welded and brazed are considered to
provide an electrically continuous connection and do not
require bonding jumpers to maintain this continuity. When
appliances are connected to the gas piping system using a
flexible metal gas appliance connector, the connector has
been found to provide an adequate electrical connection
between the appliance and the gas piping, and are considered
sufficient to meet the NEC® requirements for bonding
connectivity. Additionally, the dielectric isolation fitting
between the underground utility service line and the above
ground customer-owned piping must not be bypassed with a
bonding jumper. The isolation fitting is necessitated by the
NFGC/NEC® requirement that prohibits using the
underground metallic gas piping as a grounding electrode,
and also prevents stray currents from energizing the piping in
the premise.
Under no circumstances is any underground metallic gas
service (utility) piping to be used as a grounding electrode
because grounding electrodes are intended to carry large
currents. This can expose the piping to the possibility of
sparking that can create a hazardous condition if the service
piping is undergoing any type of maintenance.
NEC® REQUIREMENTS
The NFPA 70, National Electrical Code requires all above
ground metallic piping (water, gas, electrical conduits, etc.)
be bonded. Article 250 in the NEC® contains extensive
coverage for the grounding and bonding of electrical and
other metallic systems. The specific types of grounding
electrodes and acceptable methods of bonding gas piping
systems to them are found in Sections 250.52, 250.70 and
250.104(B). The NEC® requires that all separate grounding
electrode systems (including lightning protection systems)
be bonded together to establish an equal potential state
between these systems.
NEC® Section 250.104 (B) requires that any metal piping
including gas piping that is likely to become energized be
bonded to the grounding electrode system. The NEC® also
states that bonding of metallic systems, as a general practice,
will provide additional safety.
DEFINITIONS
The following terms and definitions are commonly used to
describe technical requirements:
Bonded (Bonding): Connected to establish electrical
continuity and conductivity.
Bonding Jumper: A reliable conductor to ensure the
required electrical conductivity between metal parts required
to be electrically connected.
Grounded (Grounding): Connected (connecting) to ground
or to a conductive body that extends the ground connection.
Grounding Electrode Conductor: A conductor used to
connect the system grounded conductor or the appliance to a
grounding electrode or to a point on the grounding electrode
system.
Grounding Electrode System: The NEC® describes the
grounding electrode system and its installation in Sections
250.50 to 250.53. Electrodes can be a metal rod/pipe/plate
driven into the ground; the metal frame of a building; buried
metal water piping; a ground ring of copper wire; or a
concrete encased foundation electrode. Buried metal water
piping can not be used as the sole grounding electrode, but
must be bonded to a second grounding electrode such as a
driven rod (250.53).
Page 2
Let see if it works at Drop Box…
Here is the link.
How about if it is on a well with a steel casing?
Thats a good ground.
No prob. Minnesota has been doing this for as long as I can look back, BUT… always check with your local AHJ for the final word in your area.
Yes, it should be, but… not always!
- unless a very old well system, it will usually have plastic service pipe,
- many systems isolate the casing and or piping with rubber/neoprene seals/gaskets.