Bonding

[Admin]

Is bonding required even when you replace a conventional vented water heater, with no electrical connections?

The answer according to the ESA is YES.  Even though there are no electrical connections between the appliance and the building, the gas piping needs to be bonded.

Clause 4.7.1 of the CAN/CSA-B149.1-05 Natural gas and propane installation code states;

4.7.1 - Electrical connections between an appliance and building wiring shall comply with the local electrical code or, in the absence of such, with the Canadian Electrical Code, Part I.

2012 UPDATE:

Clause 4.7.3 - All interior metal gas piping that may become energized shall be made electrically continuous and shall be bonded in accordance with the requirements mandated by the Electrical Safety Authority.
Note: Refer to ESA Bulletin 10-14-2 and subsequent amendments.

The following is information provided by the Ontario Electrical Safety Authority;

The Electrical Safety Authority is mandated by the Ontario Government to interpret and enforce the Ontario Electrical Safety Code (OESC) 23rd Edition/2002 (as amended by O. Reg. 62/07).

The OESC requires that the gas piping be bonded to the electrical system bonding conductor by a #6 AWG copper wire. The code also requires that a metal water piping system be bonded to the electrical system grounding conductor from the nearest cold water pipe to the electrical system grounding conductor with a #6 AWG copper wire.

Common practice is to bond the cold water piping to the electrical system ground and to then bond the gas pipe to the cold water pipe at the water heater because the pipes are always close together here and it can be done with a short #6 jumper. (Rule 10-406 and ESA Bulletin 10-14-2)

You can read the ESA Bulletin 10-14-2 - Here

Please note ESA Bulletin 10-14-2 has been replaced with ESA Bulletin 10-14-6.

I can agree with the ESA if my non-powered water heater shares a gas piping system with a powered furnace.  However, if there is only a non-powered appliance, such as a water heater or fireplace log, no bonding is required as per the NEC.

See page page 10 of the NAHB report Here

It is important to note that the NEC does not require any bonding of a gas piping system that is only connected to non-powered appliances such as a water heater or fireplace log.

I suspect this is likely to change given that CSST has been approved for use in gas piping systems.

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[Admin]

Thank you for providing this information

From the information that you have provided and the example shown in the ESA Bulletin 10-14-2 it would appear that the code from the ESA does not discriminate between appliance types, rather it indicates that the piping must be bonded.   

Therefore I would suggest that the piping should be bonded regardless of the appliance type.


Regards
David LeVasseur
Technical Service Advisor
TSSA, Fuels Safety Program, Technical Services
tel. 416 734-3351  |  fax. 416 231-7366  |  fuels_technical_services@tssa.org  |  www.tssa.org

[HVACJOE]

I was also told that on new water meters we are required to not only bond gas to water, but another bond from water to water around the water meter, the only reason I could figure out was because of the digital display on the new meters that a bond around them would prevent shorting out during an electrical short... ?? any other opinions??

[Admin]

Yeah that's right...not only does the gas piping have to be bonded to the cold supply piping, but the cold supply piping itself requires bonding to the electrical system.

The code also requires that a metal water piping system be bonded to the electrical system grounding conductor from the nearest cold water pipe to the electrical system grounding conductor with a #6 AWG copper wire.

[dmfv]

a newbie with a dumb question.

can someone clarify the differnece between Bonding and Grounding? the code book says no gas pipe can be used for grounding. From what i can see the water pipe is connected to the panels ground so am i right to assume that the #6 wire from gas to water is the bonding connection?



thanks

[Admin]

Clause 6.14.6 - Piping or tubing shall not be used as a electrical ground. An electric circuit shall not utilize piping or tubing in lieu of wiring, except for a low voltage control circuit, ignition circuit, or electronic flame detection device circuit incorporated as part of an appliance.

It is a bonding connection.  I thought the same thing when they started enforcing it.  The code book does say gas piping cannot be used for grounding, but bonding is not grounding.

Currently the NEC in Article 100 defines the terms "ground" or "grounded" as "connected to the earth or to some conducting body that serves in place of the earth." Yet, the NEC often uses the term "ground" when it really means "bond" (connected to an effective ground-fault path to clear a fault) [250.2 and 250.4(A)(5)].

Grounding: The process of making an electrical connection to the general mass of the earth. This is most often accomplished with ground rods, ground mats or some other grounding system. Low resistance grounding is critical to the operation of lightning protection techniques.

Bonding: The process of making an electrical connection between the grounding electrode and any equipment, appliance, or metal conductor: pipes, plumbing, flues, etc. Equipment bonding serves to protect people and equipment in the event of an electrical fault.

Equipotential Bonding: The process of making an electrical connection between the grounding electrode and any metal conductor: pipes, plumbing, flues, etc., which may be exposed to a lightning strike and can be a conductive path for lightning energy towards or away from the grounding electrode.