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Here is my scenario: I installed a 27kw generator with automatic transfer switch at a 12 year old house. I called to have it inspected and the inspector fails the job because the existing gas lines in the house were not bonded to the panels. He says that because the plumber used CSST gas lines(the yellow flexible corrugated lines)to connect from the apliances to the galvanized piping that the system must be bonded at the point where the gas service enters the building. Has anyone else ever come across this?
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Joined: Jul 2004
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It gets back to "are they likely to be energized" and that is an AHJ call. What size wire does he want you to use and will he just let you use the EGC of the circuit that is likely to energize the pipe? (usually the appliance on the end of the pipe). That was my take on 250.104(B) (B) Other Metal Piping. Where 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 the service equipment enclosure, the grounded conductor at the service, the grounding electrode conductor where of sufficient size, or the one or more grounding electrodes used. The bonding jumper(s) shall be sized in accordance with 250.122, using the rating of the circuit that is likely to energize the piping system(s). The equipment grounding conductor for the circuit that is likely to energize the piping shall be permitted to serve as the bonding means. The points of attachment of the bonding jumper(s) shall be accessible.
Greg Fretwell
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Hayes: Welcome to ECNForums... Here is the info over on the 'Jersey side', taken from the DCA Code Communicator back in '07, opinion of DCA Code Specialist. You can access this on line at NJDCA website.
"CSST Bonding – What is Required? There is confusion on what is going on with CSST, flexible gas piping, since the manufacturers have been sending out revised installation instructions with their material. The revisions were a result of a lawsuit in which the court stated that the manufacturers must provide a means to protect the CSST from lightning. The revised instructions are requiring that the CSST be bonded to the grounding electrode conductor. The installation instruction requirements are not in compliance with the currently adopted codes. The code requires that CSST be bonded, not grounded or used as a grounding electrode. Section 250.104(B) of the 2005 National Electrical Code (NEC) states that the equipment grounding conductor is permitted to serve as the bonding means for the gas piping. Otherwise, bonding is required to be from the CSST connector coupling to the water piping. The size of the bonding conductor is based on the rating of the circuit likely to energize the piping system. Table 250.122 in the 2005 NEC provides the conductor size based on the ampacity of the circuit. For example, if there is a gas heater with no electric at all to it and the service to the dwelling is 200 amperes, Table 250.122 states that 6 AWG copper or 4 AWG aluminum is required for the bonding conductor. The clamps installed on the water and CSST pipes must be listed and labeled in accordance with Section 250.8 of the 2005 NEC. The clamps may be a dissimilar metal, provided they are approved and listed for the use. In conclusion, no additional bonding is required where there is electric to any gas appliance, since Section 250.104(B) of the 2005 NEC permits the equipment grounding conductor to serve as the bonding means for a"(gas piping system.
John
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had an inspector in NH insist that the gas guys do the bonding
i asked 'why, i've bond wire with me in my truck'?
to which he replied that i didn't know which unions were dielectric or not
of course a VT inspector recently insisted that i DO bond the gas lines
sometimes i wish they'd all do lunch together once in a while
~S~
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~s! We had a similar issue with replacement water heaters.... Existing units (gas fired) that were installed prior to the bonding of hot & cold pipes...who installs the required 'bond'? Is an EC required? or can the plumber install the bond?
The argument was that an EC had to make a trip & install bond, and it was an 'extra' cost!
Kind of a 'don't ask-don't tell' situation!
John
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John,
Years ago when we had to bond the gas pipes, I would run a jumper from the hot water to the cold water pipe to the gas pipe. This way everything was bonded together.
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Bonding of CSST is for protection from lightning strikes in the area of the building and NOT anything to do with the wiring in the building. This has caused much confusion. To reduce incidents of failure the manufacturer of CSST requires the gas piping be bonded where it enters the building with a bond wire, based on the size of the service or as specified by an electrical engineer. This was all decided by lawyers NOT electricians. As a disclaimer they also specify that in areas prone to lightning strike the building should have a lightning protection system. Lawyers again. In Indiana CSST is not allowed to be mounted within 2 inches of any metal including duct work, water heaters and furnaces. On one job the electrician explained the bond wire would be an extra. The service was 3,000 amp and the gas pipe was on the other side of the building. The mechanical contractor replaced the CSST with black iron. Pipe is a lot cheaper than copper wire. Failure to bond puts the liability on the contractor instead of on the manufacturer of the CSST. There is one pipe clamp UL listed for use on the hex fitting of the CSST connector, but it should be the last choice for the bond connection. Best point of connection is on the iron pipe where it enters the building.
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~s! We had a similar issue with replacement water heaters.... Existing units (gas fired) that were installed prior to the bonding of hot & cold pipes...who installs the required 'bond'? Is an EC required? or can the plumber install the bond?
The argument was that an EC had to make a trip & install bond, and it was an 'extra' cost!
Kind of a 'don't ask-don't tell' situation!
maybe we need new company shirts Hotone? ~S~
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Joined: Apr 2002
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AlanN: Welcome to ECN forums!!
Yes, there is conflict with the CSST mfg instructions, and areas of the respective codes. I posted an article from the NJ DCA (State) regarding CSST above in this thread.
Within your comments above, the 'iron pipe that enters the building' is the natural gas service? Is it all iron into the ground, or just iron for the metering equipment and point of entry? Reason I ask is most here is plastic in the streets, with metal for metering and distribution on the premise.
John
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This was all decided by lawyers NOT electricians. isn't it time our trade decides something for them Al? like they should all ride pogo sticks into court UL approved of course.... ~S~
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