ECN Forum Forums General Topics of the Trade General Discussion Area checking gas bond

If the OP is running to the main that is a ground not a bond. He has now created a supplimental ground, same a cold water ground. The metal (AL) has been proven to not be adaquate to clear a fault landing gas pipe. it attempts to travel through the yellow pipe and burns a hole through it leading to bad things. The ground of the appliance is its return path to ground. I have just gone through this with one of our local AHJ and my research said the same thing how ever he insisted that I run the wire back to the panel. A meeting and a very rough quick drawing straightened him out.
Remember bonding is not grounding, but some bonds are grounding. Think swimming pool bond.

To my mind a supplemental ground is like another ground rod and such.

Bonding the black pipe provides no additional path to the earth worth mention.

The local gas company delivers the gas via buried plastic. Then it is connected to an extremely short stub of black pipe on the way to the gas SERVICE.

With our dry soils and climate... No one would consider that short path any kind of supplemental.

Every additional element brought into the GEC System does so by being bonded to it to create/extend an equipotential plane.

Connecting the neutral jumper causes the grounded conductor to be --- grounded.

All bonding connections are for fault conditions only/maintaining an equipotential plane.

Grounded conductors and their path down into the bowels of the GEC are expected to carry the return current/unbalanced current.

That's my frame of reference...

SERVICE bonding is typically 3/0 Copper -- by specification.

However, from time to time Aluminum has been used for some bonding connections when the ENTIRE run is above ground and conditions are suitable. ( Would never install near the sea coast, etc.)

Again, I only work commercial so some of my practices may not line up with residential practices. I do normally get inspected by the 'top dog' in the area. For example in downtown Oakland all of the high rises are inspected only by the City's Chief Inspector. He doesn't miss a thing.

I must say that in residential settings our AHJ just won't allow aluminum, period, in field wiring/bonding. The Poco loves it though. If your SERVICE is so huge that Copper is required ( over 3,000 Amps 208V or 480V ) you're tapped big time and the stuff is brought out just for you. It is NOT stocked. Normally SERVICES of that size move to bus duct and put the Poco Xfmr immediately outside the building.

And in my area the Poco is the Gasco.

man, this thread needs a 780 druid dude, kinda hard to find up my way, they've an interesting take on equipotential planes.

according to thier theory (or what i understand of it) , a 1,000,000 volts on one side of any given 'plane', and 500,000 volts on the other does the more damage in a split second than 1,000,000 volts evenly distributed


everything's supposed to blow up evenly....


~S~

This area is somewhat problematic, if for no other reason than that you can't see which way the electricity is flowing.

A grounding elecgtrode is supplsed to always carry a wee bit of current. This is problematic with gas lines, as we don't want to make a spark when they're working on the gas main.

This is countered by the guy at the last "Soares seminar," who stressed the need to bond the gas line to clear faults if it should somehow become energized. As others have mentioned, this is best done at the appliance.

Yet, you still have the OP's basic question of "how do I know it's a good bond?" As best I can tell, the only way to do know is to test it the same way we test other bonds and ground rods: disconnect the wire at the source, and use one of those fancy impedance testers to induce a charge on the line- and actually measure how quickly that charge dissipates. Unlike a simple resistance test, this test gives you some idea as to the ampacity the 'electrode' can carry.

If your bond 'fails,' then you'll have to do a second test, with another bond made between the panel and the pipe. This is because there remains the possibility that the pipe is isolated from the earth, and there is no 'ground path' once you disconnect the one you're testing.