Bonding Jumper for Gas Line

[Cap]

The City Building Inspector came by to inspect the gas line installation to my 16K generator. I had a licensed plumber / gas line installer do this gas installation. While the inspector approved the "rough gas pipe installation", he refused to sign off on the final gas line installation. He said that the gas line need to be electrically bonded and the galvanized gas line need to be painted with oil based paint.

I've gone through the Guardian installation manual and don't see any instructions regarding bonding of the gas line. Can anyone provide information on how this is to be done. I wasn't home when the inspector came by, but my assumption is that he is concerned about a potential lightning strike.

Cap

[Kelly Myers]

Please remember that the guardian installation manual says to follow all applicable local codes. Here in Michigan, we must bond all flex gas pipe, as well as paint all outside black pipe.

[NYS SitePower Corp.]

I love to see this topic because now we get into 'bonding' & 'grounding' which is too much of a complex topic for this board.

In NY, there is to be absolutely no interconnection between gas & electrical systems.

Now, I can see BONDING the gas line, whether steel or CSST it makes sense for a variety of reasons. However, lets consider most residential applications - how well of a ground does the customers home have? Some may be legit, while others fall short of ideal. Now lets take it to the next step, the customers ground falls short of a real ground, or worse yet it fails all togehter, where does fault current go (or a lightning strike)? The path of least resistance which may or may not be the gas system - not a good situation.

This is a complex topic on many fronts from the NEC to the electrical inspectors enforcing it and the building inspectors that may or may not have enough understanding to apply the theory.

Just my $0.02!:cool:

[NYS SitePower Corp.]

One more thought....

If you have a furnace, your gas line is already 'bonded' through the appliance's equipment ground.

Ever seen a gas appliance where the gas inlet, gas valve and associated fuel delivery system is isolated from the sheet metal of the appliance??

This is true unless of course you use a flexible rubber connection hose for your furnace, but even in that case, most flexible hoses pass continuity through the internal SS braid anyway.

....and we go on and on!

[SkipD]

The contractor who installed the underground gas line (most of which is 1" plastic pipe designed for gas service) installed a wire alongside (but not touching) the plastic pipe and tied off (but not connected to) the black pipe that is at both ends and accessible above the ground. The purpose is not to "ground" any of the gas piping but to provide the ability for someone to "trace" the path of the gas pipe using sensors above the ground.

I was told that all of the plastic piping in the gas distribution system also has parallel wiring for this purpose, as the sensors cannot actually detect the plastic pipe itself.

[M Miller]

I agree that this is a complex subject. I had CSST installed for my generator installation and after discovering that CSST had the potential for damage should lightning get into it, I did a lot of research on the subject. I also had some long discussions with my generator dealer/electrician and building inspector.
You may want to have a look at this article. http://www.toolbase.org/pdf/techinv/csst_lightningconcerns.pdf
While the article is about CSST, it also has background information about the bonding of all metallic building systems including iron pipe and the theory with all of these systems having the same "potential" to lessen the chances of lightning arcing between these systems. In theory, having all systems with the same potential means none of the systems offer the path of least resistance. The article also mentions that the bonding of gas distribution systems is required under the National Fuel Gas Code. While less likely due to the thickness of iron pipe, lightning still can burn a whole in iron pipe should it arc to/from other building systems.

[NYS SitePower Corp.]

Exactly. I see the benefits of an equipotential across the entire installation at any given site - this practice is more commonly used in the broadcast & cellular tower industry. As long as the entire installation is well grounded & bonded to ensure no difference in potential, a radio tower can take a lightning hit often without damage to any radio transmitters or electronic equipment. These are some serious grounding systems that have to be at less than 5 ohms resistance to pass!

I would just really hate for a situation where a good ground is non-existent, or has an easy potential for damage and an unknowing installer simply 'bonds' the CSST to anything he can find (kinda like the cable TV guys & phone guys do) thereby making that the building 'ground'!

I agree that this is a complex subject. I had CSST installed for my generator installation and after discovering that CSST had the potential for damage should lightning get into it, I did a lot of research on the subject. I also had some long discussions with my generator dealer/electrician and building inspector.
You may want to have a look at this article. http://www.toolbase.org/pdf/techinv/csst_lightningconcerns.pdf
While the article is about CSST, it also has background information about the bonding of all metallic building systems including iron pipe and the theory with all of these systems having the same "potential" to lessen the chances of lightning arcing between these systems. In theory, having all systems with the same potential means none of the systems offer the path of least resistance. The article also mentions that the bonding of gas distribution systems is required under the National Fuel Gas Code. While less likely due to the thickness of iron pipe, lightning still can burn a whole in iron pipe should it arc to/from other building systems.

[Cap]

It turns out that what the City Inspector meant, was that there needed to be a jumper around the rubber vibration hose, to bond the metal gas line at the generator to the rest of the gas line system. His view is that the metal parts of the gas line system need to be interconnected, irregardless of the grounding of the generator itself. So - two clamps and some #6 copper wire were what my inspector wanted.

[Kelly Myers]

Anybody questioning the bonding of flex gas pipe should read about the CSST settlement here:
http://www.pddocs.com/csst/faq.aspx

Due to the cheap cost of CSST, and the ease of installation, it is extremely common in generator installations in the midwest.



I try to avoid bonding/grounding questions on this site because they vary so much from jurisdiction to jurisdiction. I would hate to give somebody some advice that would satisfy Michigan code, but fail in your local municipality.