ECN Forum Forums General Topics of the Trade General Discussion Area to bond or not to bond?

Each state can be different baldelectrician, such as here in California we just adopted the 2002 code, while other states are on the 2005 NEC.

Then each city in California may adopt local changes to the NEC.

Then ofcourse, each inspector has their own ideas of what is needed.

I have never bonded a gas line here in Southern California. I've been told The Gas Company doesn't want it.

AtticRat,
Can you cite a documented source for that? Gas in the pipe is way above UEL (upper explosive limit) and will not burn. Yes, it is very possible to ignite the gas as it escapes from the pipe, but that would not cause an explosion and I would not expect serious injuries...maybe burns, and yes if the gas is not shut off the building may burn down.
How do you isolate the gas line? It will have a connection back to the electrical system from the gas/electric equipment that the gas line feeds.
Don

I have worked on a number of residential furnaces where there was no solid connection between the burner assembly and the furnace itself. The burner assembly just sits in brackets, without screws or other mechanical bonding. In this type of equipment the furnace EGC, does not provide a good bond to the gas piping.
Don

In Germany similar to the Uk bonding on the client's side is mandatory as defective electric equipment connected to the gas pipe anywhere in the building could transport dangerous voltage. If ungrounded this cannot be detected properly.

The incoming gas pipe in front of the meter must now have a piece of electrically isolating plastic. This is to prevent 1. corrosion and 2.import of external voltages from the neighboured house for example. Gas pipes other than old water pipes are usually covered with isolating anti corrosion material and so do not have a low ground resistance. (New water or gas pipes now are always in PE outside of a building anyway)

As plastic pipes within a building would be an important fire risk and prohibited, imho it will be impossible to isolate the electrical part of gas equipment from gas transporting part as lamplighter has proposed.

... No Don, sorry, This was told to me by an instructor at one of my CEU classes... maybe an urban legend,and he wanted to shake us up a bit so we wouldn't do it.???
If it's not true,and that sort of explosion can't happen,I don't want to perpetuate the myth..You'd know better than me..
Russ

Where I'm at... Pre-2001 CEC ( '99 NEC with Changes) we bonded gas at the water heater usually. Hot cold and gas.... It was a typical check list item....

Then the '99 NEC was adopted as the 2001 CEC, and a few things changed... (Oh, can anyone tell me what that "x" is for?)

Then we had to bond gas to the service GEC from just past the meter, without it being between the electrodes...

Now we just started doing it on the new 2004 CEC (2002 NEC with changes)

Now I don't know what to make of it... If you're coming from a sub-panel for the circuits for Furnace or other gas appliances, you would then have to bond the gas to the main? Do we go back to the water-heater method? Bond anywhere to water? (As the cold water is always a GEC here.) Or stick to the real PITA '99 NEC method of back to the Main GEC? (At the gas meter from the service, which can be on opposite sides of the house.)

Only time will tell...
FYI I'm still being asked for the PITA '99 method lately.... Although it seems clear to me that its no longer nessesary.


[This message has been edited by e57 (edited 10-26-2005).]

NORCAL

Mark(E57), that small "x" "...indicates that material has been extracted from other NFPA codes and standards. The source documents are identified in Appendix A."

Edit - Appendix A states A-250-104(b) is from the National Fuel Gas Code, NFPA 54-1996.

steve

[This message has been edited by stamcon (edited 10-26-2005).]

I just finished my code update class today and gas pipes were ofcourse a topic.
According to Art. 250.104(b), as several of you have stated, the gas pipe is required to be bonded, however, the equipment grounding conductor can be used for this purpose.
According to my instructor,(a local AHJ), the gas pipe need not be bonded with any bonding jumpers since the E.G.C. is allowed to act as the bond itself.
According to him, the E.G.C. meets the requirements of the code and no further bond is needed.

I can see both sides of the issue here. It's sorta like fueling an airplane, you touch the clamp from the fuel truck chassis to the airplane metal before you let fuel flow. Electrolysis is an issue with metal pipe in the ground and no sleaving so you might not want it grounded. For safety in the house, it probably makes sense to ground it. All I know for sure is that I wouldn't touch the meter without bonding around it first, to make sure I would get any sparks because of a potential difference.