Bonding Gas(again)

Status
Not open for further replies.

ram11379

Member
I see there are multiple threads about this issue but I am not seeing my questions answered in any of them. My local gas companey is requesting bids to bond around 100 gas systems in trailers in my town. They are using a Pro-flex system and requiring that a bonding clamp is connected to the brass fighting they have installed(I imagine this is the isolation fitting I am hearing about). From there they are requiring a bonding wire the size of the full amperage available through the electrical service(all 100 amp services so #4 copper I assume they mean). But they do not say if the wire needs to go to the panel or if it can bypass the panel and I can split bolt it directly to the main cround coming out of the panel to the ground. In this case since it they are all trailers it would be easier to go directly to the ground wire because the pipe and wire are both under trailer. I contacted them and they said they are leaving it up to the contractors. I want to know if there is any reason I can not just bypass the panel and go straight to wire directly over rod. And also does anyone know the clamp size I will be needing to connect to the pro-flex brass fighting?

P.S. Sorry for huge messy paragraph I'm in a bit of a hurry.
 

ram11379

Member
JohnJ0906 said:
250.104(B)

If by "main ground" you mean the GEC, you should be OK.

Sounds like they want an oversized conductor, but if they want to pay....
Yes I do mean the ground coming from main panel to ground rod. And I believe there theroy on the size of ground wire is lightning protection.
 

charlie tuna

Senior Member
Location
Florida
i have been told a number six copper ground is the standard and it can connect anywhere on the EGC. the gas companies refer to the gas code for their information...
 

Cavie

Senior Member
Location
SW Florida
ram11379 said:
I see there are multiple threads about this issue but I am not seeing my questions answered in any of them. My local gas companey is requesting bids to bond around 100 gas systems in trailers in my town. They are using a Pro-flex system and requiring that a bonding clamp is connected to the brass fighting they have installed(I imagine this is the isolation fitting I am hearing about). From there they are requiring a bonding wire the size of the full amperage available through the electrical service(all 100 amp services so #4 copper I assume they mean). But they do not say if the wire needs to go to the panel or if it can bypass the panel and I can split bolt it directly to the main cround coming out of the panel to the ground. In this case since it they are all trailers it would be easier to go directly to the ground wire because the pipe and wire are both under trailer. I contacted them and they said they are leaving it up to the contractors. I want to know if there is any reason I can not just bypass the panel and go straight to wire directly over rod. And also does anyone know the clamp size I will be needing to connect to the pro-flex brass fighting?

P.S. Sorry for huge messy paragraph I'm in a bit of a hurry.
If you read the install instructions for the flex gas pipe, it will tell you to bond with a #6. You can go to the panel or to the ground rod. Remember,you are bonding, not grounding. A split bolt should be fine. The brass fitting they refer to is at each end of the flex. Standard pipe clamp should fit, The connection must be accessible. I my be wrong, won't be the first time
 

ram11379

Member
Thank you all for your imput. Bid complete. Stilll interested if anyone has anymore input on this though. I like to get as mush knowledge as possible on something I haven't had allot of experience with.
 

Kenosha

Member
Flex gas pipe bonding

Flex gas pipe bonding

Its my understanding the reason this has become an issue is because there was a fire which I believe was the result of a lightning strike which energized the underground gas line and traveled through the flexable coated gas line and through the appliance. The result was tiny pin holes created in the flexable gas line which caused the gas to leak which resulted in an explosion.( Thats what I heard) The confusion exists because no one can answer where to
bond the gas line. Bond at the gas service in to prevent the lightning from entering or bond at the appliance in case lightning strikes the bulding. My opinion is bond at the gas service and bond at the appliance as we did with iron water pipe with unions. This will help prevent any strikes from entering the building and also help strikes which hit the building and follow a path to ground.
 

M. D.

Senior Member
Right now this is a bit confusing this is from document I linked to ,..somwhere on here

Although only four of the six CSST manufacturers were parties to the Class Action suit,
all six have informally agreed to upgrade their bonding requirements for the CSST
system. Generally speaking, the new bonding method requires the attachment of a
bonding clamp to either the CSST fitting or to a piece of steel pipe located near the
service entrance to the building. The bonding jumper shall be no smaller than a 6 AWG
copper wire (for residential applications). Although the final bonding solution is
essentially the same for all six manufacturers, the six technical pronouncements
appear to be quite different.
The 6 AWG copper bonding wire solution can be developed through different
interpretations of the electrical code. One approach uses the water piping as a direct
comparison in terms of sizing of the bonding jumper. In another case, the size of the
bonding jumper is based on the size of the bonding jumper used for a lightning
protection system. If NEC Table 250.122 is used, then the selection of a 200-Amp
service results in a bonding jumper of size 6 for copper wire. There are other similar
bonding jumper sizing approaches used for communications cable and other metallic
systems that also lead to the use of a 6 AWG copper jumper.
What is problematic is the requirement to size the bonding jumper in accordance with
Table 250.66. This table is intended for sizing of the grounding electrode conductor (not
the same as the bonding jumper) which is based on the size of the ungrounded service
conductor at the entrance of the building. This can result in a bonding jumper much
larger than a 6 AWG copper wire especially for large buildings and/or multi-family
structures. Using the exception in Section 250.66(A), if a rod, plate, or pipe is used as
the grounding electrode, the grounding electrode conductor need not be larger than a 6
AWG copper wire. The argument still must be made (to the local electrical inspector)
that the bonding jumper be sized in a similar fashion. However, this exception is open

[FONT=arial,sans-serif][/FONT]
to interpretation and can be misused when sizing the bonding jumper. Therefore,
caution is recommended when referring to this particular section of the NEC.
Until these six sets of installation instructions are written with identical language, there
will be confusion in the field (both installers and inspectors) and the real possibility of
improperly sizing the bonding jumper. Efforts are underway to remedy this situation

 

don_resqcapt19

Moderator
Staff member
Location
Illinois
there was a fire which I believe was the result of a lightning strike which energized the underground gas line and traveled through the flexable coated gas line and through the appliance
There have been multiple fires with lightning as the suspected cause, but not by the current on the underground gas pipe. It was induced current on the CSST gas line that generated enough voltage to cause a "side flash" beteen the gas line and some grounded object. This caused a gas leaks and fires. If the interior gas line is bonded to the service grounding system, it should limit the possibility of side flashes.
Don
 

Curt R

New member
HI I am wondering if bonding is required in all municiplaities. I have yet to see any gas pipes bonded here in Minnesota. I have owned several homes and have had 2 built in recent years and there isn't any bonding on the gas lines. I find it intresting that lightening is mentioned. A summer does not go by where several homes in the city I live in are burned when lightening strikes the gas meters attached to the side of the house. Thanks, Curt
 

George Stolz

Moderator
Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
Curt, welcome to the forum. As I understand it, the bonding of that flexible CSST gas line is now required by the listing of the gas pipe itself - the NEC does not require it to be bonded/grounded. Since gas line is not an electrical installation, it's the plumber's responsibility to have an electrician make whatever electrical connections the gas line's listing requires.
 
Status
Not open for further replies.
Top