Gas piping "likely to become energized"

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Trowbridge - Martin

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A prefab gas ventless fireplace is being installed with a battery operated starter. The metal gas pipe 2 ft long, from outside connects to/thru fireplace. Does gas pipe need to be bonded ? What is forums definition of "likely to become energized"?
Thank you, Tom


310.1 Gas pipe bonding. Each above-ground portion of a gas piping system that is likely to become energized shall be electrically continuous and bonded to an effective ground-fault current path. Gas piping shall be considered to be bonded where it is connected to appliances that are connected to the equipment grounding conductor of the circuit supplying that appliance.
 
Unfortunately likely to be energized has never been defined. IMO, no it would not need bonding. Art. 250.104(B) specifically states the egc of the circuit that is likely to energize the piping shall be permitted to serve as the bonding means. This, IMO, means that we never have to bond the gas pipe unless it is the CSST-- corrugated stainless steel tubing- AKA- the yellow stuff, or the circuit that supplies the gas equipment does not have an egc.
 
I don't believe that the NEC requirement was ever intended to require a specific bonding conductor to be attached to the pipe and run to the panel.

To put things into 'practical English,' what I think they really meant to say was 'gas pipe is not likely to become energized unless electricity is present. If electricity is present - say, in the form of a blower on the appliance- then we expect that everything will be bonded to the ground wire of the incoming circuit. If the power is 'low voltage' - examples include the generated power of a piezeo-electric igniter or a small battery- you don't need to worry about bonding either.'

Bonding of gas lines has always inspired a lively debate, simply because of the different safety issues that can arise. You don't want a blower to fault to the pipe, and not have it grounded - but you also don't want every stray current in the house running through it either, as this will cause a spark when the lines are worked on. Remember, the NEC allows current to flow over the ground path, as long as it's not an "objectionable" amount. Naturally, the advent of CSST has introduced an entirely different set of issues to the question.

As for your situation- I would not consider an ordinary battery to be reason enough to say that anything is 'likely' to become energized.
 
One of the worst phrases in the NEC.

If it is likely to be energized, somebody is doing something wrong!

I think the code writers get lazy some times. They couldn't come up with the right description so they gave up, threw that in and moved on.
 
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