CSST Bonding / Grounding

O

olly

Senior Member
Location
Berthoud, Colorado
Occupation
Master Electrician
I have never bonded or grounded a CSST gas pipe. It came up on an inspection report. From my research I believe you try to find where it connects to solid pipe, and then you install a normal water pipe style grounding lug. The inspector told the realitor, oh its easy you clamp a bond from the CSST to the hard pipe. I dont think you are suppost to put the clamp on the CSST....?? Or are you. If so where do you run the ground wire?
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No the clamp does not go on the CSST it goes on the black pipe with a bonding jumper to the building GES. Also this is not in the electrical code and is part of the listing of the gas pipe. Some brands of CSST do not require additional bonding jumpers.
 
tthh said:
Last one I did just happened to have a CSST brass connector fitting about 6 inches away from the GEC so just used the clamp on the CSST brass
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Is that clamp listed for attachment to the actual CSST connector or is it listed for connection to a metal pipe?
 
You just run a #6 wire from a ground at a panel or from a grounding electrode and connect it to a solid piece of steel pipe that is connected to the CSST, or find a fitting that bonds to a CSST fitting.

It appears that this one might be listed for both by the installation instructions. Did not dig in to the listing past the HD website. I always see it bonded to a steel pipe connected to the CSST. - https://www.homedepot.com/p/HOME-FL...-System-Brass-Bonding-Clamp-11-05BC/205699930

In my opinion, the yellow non-arc resistant CSST should just be illegal. There is no way the #6 bond wire truly prevents the pinhole issue from the induced lightning voltage. In fact, I have seen at least one case locally where it didn't and a fire started in a floor cavity.
 
tthh said:
Last one I did just happened to have a CSST brass connector fitting about 6 inches away from the GEC so just used the clamp on the CSST brass connector without using any power tools so as not to possibly deform the connector.

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Thank you for that cheat sheet.

Would you agree plans should prohibit CSST, since this bonding is excluded from the NEC, perhaps other trade books, and rarely found in compliance?
 
ramsy said:
Thank you for that cheat sheet.

Would you agree plans should prohibit CSST, since this bonding is excluded from the NEC, perhaps other trade books, and rarely found in compliance?
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The black CSST is arc-resistant and does not require a separate ground wire, so I would not exclude all CSST. But I would certainly prohibit "non arc-resistant CSST" on any plans I would draw or have influence on. I think TracPipe Counterstrike and Gastite Flash Shield are good products. The yellow stuff you get from the big box store, not so much.

For those interested, the requirement for this bond is laid out in the International Fuel Gas Code (or NFPA 54 if your jurisdiction is weird), and the manufacturer's instructions for non arc-resistant CSST gas pipe that a #6 copper wire bond less than 75' in length is required.
 
I was also a Master Gas Fitter before I retired in addition to electrical. IMHO CSST should be outlawed. This product was pushed through as a cheaper, easier to install gas pipe and everyone swallowed what the MFGs were selling.

It is a very weak product IMHO. The core is less robust than a gas appliance connector and is less robust that LMFC and you wouldn't run gas through that.

If you find a scrap to look it the inside is like tinfoil.


I did install it 3 times and it has its place, but I don't like it. Once was a temp line for a roof top unit,. we used it while the gas piping was being reworked.

The second job was an existing police station that had heat pumps AHUs in the attic and they wanted them replaced with gas furnaces and we had to get a gas line from the basement to the attic in a finished building.

The third job was installing a furnace in a garage in an existing house with the gas meter at the other end. The entire basement was a drop ceiling wit 2' square tiles so the whole ceiling would have to come down to use hard pipe.

After the issues with lighting strikes Massachusetts banned its installation for a while. Then due to pressure from the MFGs they let it back in. I was hoping they wouldn't.

Gas is dangerous and needs better protection than CSST can provide IMHO
 
infinity said:
No the clamp does not go on the CSST it goes on the black pipe with a bonding jumper to the building GES. Also this is not in the electrical code and is part of the listing of the gas pipe. Some brands of CSST do not require additional bonding jumpers.
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image001.png

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 any of the following:” there are 5 bonding methods ( not going to list all here but #2).
(2) Service equipment enclosure and sized by Table 250.122.
In Texas we are bonding gas piping to the service equipment enclosure.
 
Rjryan said:
View attachment 2578812

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 any of the following:” there are 5 bonding methods ( not going to list all here but #2).
(2) Service equipment enclosure and sized by Table 250.122.
In Texas we are bonding gas piping to the service equipment enclosure.
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The EGC run with the circuit that is likely to energize the gas piping is all that is required. No additional bonding needed. CSST which is not part of the electrical code may have additional requirements.
 
infinity said:
The EGC run with the circuit that is likely to energize the gas piping is all that is required. No additional bonding needed. CSST which is not part of the electrical code may have additional requirements.
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Based on the NEC 2023 250.104 (B) there are 5 different way of grounding metal piping systems, including gas piping.
There are types of CSST that require grounding, by the manufactures specification. In the NEC all 5 ways, are valid to ground gas piping.
While your method is one way, it does not exclude the other four. I am just stating what inspectors are requiring in my area.
 
infinity said:
Is that clamp listed for attachment to the actual CSST connector or is it listed for connection to a metal pipe?
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Just like this in the attachment. The connector came from big orange over in the CSST area and is made for whatever CSST they are selling. It says it can be used on the black steel pipe or one of the CSST connectors.
1753736906661.png
 
Rjryan said:
Based on the NEC 2023 250.104 (B) there are 5 different way of grounding metal piping
While your method is one way, it does not exclude the other four. I am just stating what inspectors are requiring in my area.
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My point was that according to the NEC you cannot require one method over the other.
 
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