Bonding gas line question.

[skeletonizer]

So I changed out the mother-in-law's oil furnace to a 95% propane unit. The inspector dinged me for not grounding the gas line into the house electric system. I'm fine with that and happy to make it right.

The problem is the gas line comes into the Southeast corner of the basement and the electric service is on the Northwest corner in the garage.

I called "the man" and asked if I could drive a grounding rod by the gas regulator and ground the pipe there instead of buying 100' of #6 bonding wire and crawling all over hell installing it.

His answer was of course, "No." He did say I could ground it to the water pipes if they were metallic and themselves bonded. They aren't.

My question is why? Would grounding the gas pipes on their own rod not be just as effective as running 100' of wire to do it in the panel?

What will that much of that wire cost?

 

[mrb]

the gas pipe needs to be at the same potential as the rest of the electrical system and bonded components. Sticking a metal rod in the soil doesnt accomplish this -the gas line needs to be bonded to the electrical system's ground.

 

[MrMark]

You can't do what you wanted to do. Those are two different things going on. The bonding of the gas line is so that a short to the metalic gas line (the gas line becomes accidentally energized by a hot line hitting it) will trip a breaker and the fault can be found and cleared. The basic rule is that anything metal that electrical can hit needs to be bonded to the service neutral.

Now, you can achieve this bonding right at the water heater by jumpering cold water to gas line.

 

[mrb]

Now, you can achieve this bonding right at the water heater by jumpering cold water to gas line.

only if the water line is an uninterrupted metallic path back to wherever its bonded to the electrical service, which here i think he said its not.

 

[Speedy Petey]

If the gas line is metallic all the way with no breaks, like can happen with CSST fittings, the ground of the circuit feeding the furnace IS your bond.

250.104(B) Other Metal Piping. If installed in, or attached to, a building or structure, a metal piping system(s), including gas piping, that is likely to become energized shall be bonded to the service equipment enclosure; the grounded conductor at the service; the grounding electrode conductor, if of sufficient size; or to one or more grounding electrodes used. The bonding conductor(s) or jumper(s) shall be sized in accordance with 250.122, using the rating of the circuit that is likely to energize the piping system(s). The equipment grounding conductor for the circuit that is likely to energize the piping shall be permitted to serve as the bonding means. The points of attachment of the bonding jumper(s) shall be accessible.

 

[mrb]

CSST has some pretty specific bonding requirements and the circuit ground to a furnace doesnt meet it.

 

[Speedy Petey]

CSST has some pretty specific bonding requirements and the circuit ground to a furnace doesnt meet it.

How 'bouts you fill us in on these requirements?

 

[mrb]

How 'bouts you fill us in on these requirements?

heres a small snippet http://www.gastite.com/include/languages/english/downloads/pdfs/TB2010-01.pdf

 

[VHF]

If the gas line is metallic all the way with no breaks...the ground of the circuit feeding the furnace IS your bond.

I agree. The ground wire in the banch circuit feeding the furnace provides the grounding bond to the gas piping. I think that most inspectors accept the furnace itself as the bonding connection, but I suppose some might require a jumper to the gas pipe to keep the gas piping bonded in case it is disconnected from the furnace.

We are only bonding the metalic gas piping to keep it at the same ground potential, not grounding to it (such as using an incoming metalic water pipe instead of a ground rod), so no need for a #6 wire!

 

[Speedy Petey]

I agree. The ground wire in the banch circuit feeding the furnace provides the grounding bond to the gas piping. I think that most inspectors accept the furnace itself as the bonding connection, but I suppose some might require a jumper to the gas pipe to keep the gas piping bonded in case it is disconnected from the furnace.

They can ask, but it is NOT code required or necessary.

We are only bonding the metalic gas piping to keep it at the same ground potential, not grounding to it (such as using an incoming metalic water pipe instead of a ground rod), so no need for a #6 wire!

True!

 

[Speedy Petey]

heres a small snippet http://www.gastite.com/include/languages/english/downloads/pdfs/TB2010-01.pdf

So who's requirement is this? It is contrary to what the NEC says, so someone of authority has to be behind it for it to be valid.
Is it simply this manufacturer's requirement?

 

[brewchief]

I believe it is a manufacturers requirement but there is something in the mechanical code that requires CSST to be installed to the manufacturers directions and that includes bonding if required.

 

[cowboyjosh]

New Counterstrike CSST and FlashShield (black sheathing instead of yellow supposedly more lighting resistant then the yellow ****) requires no additional bonding.

 

[ishiboo]

So who's requirement is this? It is contrary to what the NEC says, so someone of authority has to be behind it for it to be valid.
Is it simply this manufacturer's requirement?

NEC guidelines were written when black iron pipe was the standard. I believe that the NEC requires the bonding so that there is a return path for current to flow and trip a breaker if a gas line becomes energized. This requires only a moderately-sized conductor.

CSST manufacturers also have to worry, due to the construction and thin nature of CSST (being flexible) to maintaining integrity during a lightning strike, so the manufacturer requires bonding in excess of the NEC and most local code. (6AWG)

Of course manufacturer installation requirements have to be followed in addition to any and all code that applies.

 

[acer66]

If the gas line is metallic all the way with no breaks, like can happen with CSST fittings, the ground of the circuit feeding the furnace IS your bond.

This is how it was done at our place and it passed inspection.
But he also used a ground clamp on the pipe and connected it to the furnace ground.

 

[sberry]

As I recall there is language to the effect that the bond needs to be sized so anything that has the potential to energize it can be cleared, about the biggest thing in a house anymore other than a range is 30A water heater circuits, maybe an air cond? Most places a 12 would likely be suffecient, agreed in some cases this could come from the furnace if it was on 20A circuit.

 

[PRH44]

7.13.2 CSST. CSST gas piping systems shall be bonded to the electrical service
grounding electrode system at the point where the gas service enters the building.
The bonding jumper shall not be smaller than 6 AWG copper wire or equivalent.

 

[Speedy Petey]

7.13.2 CSST.

Who's code is this?

Other than 110.3(B) nothing in the NEC specifically applies to CSST.

 

[Speedy Petey]

Got it. NFPA 54: National Fuel Gas Code

 

[acer66]

Good point about the size of the wire, I am not sure what size it is at our furnace but it is thicker than 10g.