[Richo]

My house is in the process of being sold and an inspection was done. One of the things that needs attention is the CSST used for natural gas. It needs to be bonded to ground. I looked this up and it seems pretty straightforward.

I do have 2 CSST lines branching off the steel pipe. Do each of these need to grounded separately, or is one bonding clamp on the steel pipe near the intersection (red arrow) sufficient?

Is it just a matter of running a 6 ga ground wire from the clamp to the grounding bar inside the service panel?


Thanks

 

[Datawise]

The rules in the NEC may be different, but you should be able to pick up that gas line anywhere. When we do services (in Canada), the gas meter is usually pretty close to the panel and we pick it up right there or at the water tank (bond the gas to the cold water line).

It is important to check your local rules, because an improper connection on or near a CSST line can be hazardous.

Cheers
John

Cheers
John

 

[Richo]

This is from the website of the energy company that supplies gas to the house.

https://www.we-energies.com/outages_safety/using_energy_safely/CSST_policyreq.pdf

It says to connect to the piping as close to the gas meter as possible, but the CSST connections are on the exact opposite side of the house from the meter, as is the service panel. Everywhere else I look, it says to bond to the steel pipe as close to the CSST connection as possible, or even to the CSST fitting.

 

[Datawise]

I am not aware of any CSST "ground connectors" available in Canada; there maybe (as it appears) to be some approved in the USA.

All I can offer is what we do in Canada that is acceptable. In Canada we use the main copper water line as a grounding electrode. This allows us to "jump" to the gas line at the water tank (gas line to cold water copper line).

If that option is not available or is impracticable, we might pick up the gas line on the way to the water line or the ground rod / plate if the main water line is plastic.

Or we may just may jump the gas and cold water line in a easier location that is accessible. Our code requires us to connect the copper water lines, iron gas pipe, ducting and any other metal parts to the ground rod / plate or the main water line at the meter if copper.

The appliance(s) that the CSST are connected (usually furnace and on demand water tank) to are "grounded" through he 120v / 240v cable that is powering them; there is not an "electrical connection" from the appliance to the iron pipe through the CSST that is why they need to have the separate connections.

From an electrical perspective, that #6 bare wire can be attached to the iron pipe (gas line) anywhere and you will get the same result (as long as it is a all iron pipe back to the gas meter).

Hope that makes sense.

Cheers
John

 

[Richo]

I kinda figured that was the case where it shouldn't really matter where you bond to the pipe, just as long as it's a solid connection.

 

[Datawise]

I did a quick search for a couple of pics to explain...

Cheers
John

 

[Jim Port]

The bond goes on the black iron pipe. AFAIK there are no clamps listed for use on the CSST fittings.

The NEC considers the gas line to be bonded by the egc. The additional rules are from the manufacturer's instructions and the fuel gas code.

 

[chandler48]

Wondering, too, why CSST would need a separate ground. It is a continuous metal connection from the iron pipe.

 

[AllanJ]

(U.S. rules)

Specifically, bonding one end of CSST to ground technically does not adequately ground what is at the other end.

The gas appliance, if it uses AC power and is properly grounded, will bond one end of the CSST to ground . Bonding rigid metal gas plumbing to a grounding electrode conductor (or panel ground or grounding electrode itself) will bond the other end of the CSST.

Bonding gas plumbing to a water pipe technically does not qualify either, unless to the five foot or shorter length of pipe between the clamp for the GEC and where the pipe exits underground.

Clamping to CSST is rarely if ever permitted because there are obscure circumstances where a hole could be made in the CSST.

 

[Jim Port]

Wondering, too, why CSST would need a separate ground. It is a continuous metal connection from the iron pipe.

The trouble is it pinholes if it carries any voltage like during a lighting strike. Newer products do not have the same issue ie Counterstrike.

 

[Jim Port]

Specifically, bonding one end of CSST to ground does not adequately ground what is at the other end.

The gas appliance, if it uses AC power and is properly grounded, will bond one end of the CSST to ground . Bonding rigid metal gas plumbing to a grounding electrode conductor will bond the other end of the CSST.

The Fuel Gas code only calls for a bond on one end.

 

[Datawise]

Wondering, too, why CSST would need a separate ground. It is a continuous metal connection from the iron pipe.

Not a separate ground per se, just a continuation of the existing one.

My understanding is that there are gaskets on the CSST connectors that prevent the continuity of the bonding of the gas line to the appliance and the iron pipe.

Very much the same idea as having a piece of copper water line with a section of plastic PEX in it; the electrical code requires you to "jump" the section of PEX to ensure continuity of the water pipe.

Cheers
John

 

[Jim Port]

Seems strange that the bond is on the black iron if there are gaskets or washers in the fittings potentially isolating the CSST.

 

[Datawise]

I agree... what we were told in our code update class that the CSST essentially is like PEX; an ungrounded portion of the pipe because of the gaskets in the fitting. The appliance is "bonded" through the power wiring. So my understanding is that the CSST is "floating" in the middle of the two. Because both sections are at the same potential, there is little to no risk of the CSST seeing the any difference.

Cheers
John

 

[bfrabel]

Wow, lots of mis-information here. There are no "gaskets on the CSST connectors that prevent the continuity of the bonding of the gas line".

The gasket is in the connection to the gas meter, where a dielectric union is. Most gas piping that's made out of black iron pipe isn't technically grounded, except for places where it might be in contact with the building structure (or, as has been mentioned the equipment ground, but I guess this isn't good enough for CSST).

The lack of gas piping ground didn't used to be much of a problem, since black iron pipe is thick and strong enough to withstand a little voltage spike caused by lightning, so the code has left it alone.

CSST in comparison, is thin and weak. If lightning hits a CSST piping system and causes an arc to jump from the CSST to a nearby ground source, it will burn a hole right through the CSST. That's why a better source to ground is important with this stuff.

My understanding is that the code was changed a few years ago that pertains to this. It used to be that the 6 guage bonding jumper needed to go from the CSST fitting or steel gas pipe directly to a ground rod or a ground lug inside of the breaker panel. This has recently been changed to allow metal water piping or building structure to take the place of that. Also, as has been mentioned, there is a type of CSST available that is supposedly made better so that it doesn't require the bonding jumper. This kind is usually black instead of yellow. As always, check with your AHJ with any questions.

There really isn't anything special about the clamps. They look like this and if you go to a Home Depot-like place they can be found in either the plumbing section near the CSST stuff, or in the electrical section. The generic ones in the electrical section are usually cheaper than the ones in the plumbing section, but for all intents and purposes they are the same thing.

 

[chandler48]

The gasket in CSST doesn't isolate the CSST from the iron pipe. The female fitting goes hard against the brass clamp ring and connects to the male iron pipe. The gasket just keeps seepage from going outside the ID. Corrections, please. Curious as the OP was.

 

[Oldmaster]

Inspection here requires bonding to the CSST pipe, usually at a fitting. Reasoning is the fitting on CSST may contain a non conductive bushing which could compromise the bonding integrity.

 

[bfrabel]

Inspection here requires bonding to the CSST pipe, usually at a fitting. Reasoning is the fitting on CSST may contain a non conductive bushing which could compromise the bonding integrity.

Nope. I don't doubt that's their reasoning, but it's wrong. I'm guessing most electrical inspectors have never installed CSST or seen the inside of the fittings. Inspectors sometimes make up stuff to explain things that they don't understand, and then everyone believes them since they are the inspector so they must know what they're talking about.

The CSST is stainless. The fitting is brass or stainless. The fitting and the tubing are in direct contact with each other. There is no rubber or paper or plastic or any other type of "non conductive bushing" anywhere in this process.

The "non conductive bushing" is at the gas meter. Actually 2 of them. One on the inlet to the gas meter, one on the outlet. Walk outside of your house right now and go look at it and you will see.

Then go back a page and read my long rambling post #15 that I made.

 

[Oldmaster]

I am gastite certified and just finished one of the training sessions. I would agree with you it's probably not an issue but from an inspectors standpoint it's not UL listed as bonding fitting and due to dissimilar metals a problem could arise. There is a committee looking at this but at this point as far as I know it's still required. I don't make the rules, just enforce them.

 

[bfrabel]

I am gastite certified and just finished one of the training sessions. I would agree with you it's probably not an issue but from an inspectors standpoint it's not UL listed as bonding fitting and due to dissimilar metals a problem could arise. There is a committee looking at this but at this point as far as I know it's still required. I don't make the rules, just enforce them.

Maybe I'm missing something, but the CSST is UL listed, and so is the clamp. The clamp that I suggest is made out of bronze, which should be fine to have in contact with the with brass or stainless CSST fitting and the copper wire. There shouldn't be any issue with electrolysis or corrosion caused by it.

Here's a link to a clamp from Home Depot that says it's UL certified...
https://www.homedepot.com/p/Bronze-Ground-Clamp-1-1-4-2-in-J2BB-B1-5/202907607

Oh crap. I just tried searching google for "gastite ul listed" and didn't come up with anything. Gastite does have a few other certifications and listings, but UL seems to be missing. Very interesting...

The instructions for Gastite does say it's ok to bond to either the fitting or the pipe, but perhaps you are correct and it's better to just clamp onto the steel pipe. Easy enough. Hey, wait a second, the steel gas pipe isn't UL listed either...

Were you actually talking about the black CSST not needing to be bonded? My local inspectors have gone back and forth on this issue. From what I was originally told, they still wanted it bonded, even though the instructions said you don't need to. I was also originally told that the yellow kind wasn't even allowed anymore. Then about a month ago I asked one of them again and was told that the yellow kind is still OK to use and the black kind doesn't need the bonding jumper.

Sometimes I guess it's up to whatever your inspector wants.

Note... I am Gastite certified also, but I (thankfully) don't have to deal with the stuff very often. Maybe once every couple of years we get a job where we end up using it. It's kind of a last resort type of deal. I'm a HVAC guy. I just lurk in this forum to give all of the electricians a hard time