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CSST bonding

Jells
Jells Member Posts: 456
I just ran across the CSST bonding issue while reading up on something else. Most of the posts about it here are old so I though I'd ask fresh.

I have a couple of lengths of CSST installed by pros before 2009 when apparently this became codified. No bonding anywhere on the black pipe. My 150A panel is bonded to the cold water pipe where it enters the basement, the gas enters just a few feet away. Can I just use bonding clamps on both pipes and run a wire there? Or is even the cold water panel bond obsolete and I should have ground stakes through the slab? This is a 120 year old building so all the piping to the street is metallic.

Comments

  • PC7060
    PC7060 Member Posts: 739
    Around here the bonding is to the ground in the CB panel with 6 GA copper and the CB panel ground is tied to two 8' rods installed with 4GA copper driven into ground outside the house.

    I have seen older Gas systems ties to a dedicated ground round just prior to the meter.
  • pecmsg
    pecmsg Member Posts: 2,950
    Jells said:
    I just ran across the CSST bonding issue while reading up on something else. Most of the posts about it here are old so I though I'd ask fresh. I have a couple of lengths of CSST installed by pros before 2009 when apparently this became codified. No bonding anywhere on the black pipe. My 150A panel is bonded to the cold water pipe where it enters the basement, the gas enters just a few feet away. Can I just use bonding clamps on both pipes and run a wire there? Or is even the cold water panel bond obsolete and I should have ground stakes through the slab? This is a 120 year old building so all the piping to the street is metallic.
    That depends on the jurisdiction having authority. 
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 12,134
    edited May 20
    You're confusing two different things.

    The "grounding electrode systems" must be connected to your panel and to the metal cold water pipe (if one exists) on the street side of the water meter with a "bonding jumper" to the house side of the water meter using one continuous wire. Size depends on Main breaker size in the panel #8 or larger for 100 amp, #4 or larger for 200 amp (those are the copper sized, Aluminum can be used in some circumstances)

    As far as ground rods go, if an older service (without ground rods) is updated 1 ground rod must be added. If it tests less than 25 ohms to ground it needs to be connected to the GEC system with #6 copper minimum.

    If the ground rod is not tested (and most are not, because few have the equipment) then a second ground rod 6' away from the first (minimum distance) is added.


    The gas pipe is not ever to be used as a ground or to be part of the GEC system but should be connected by a ground wire to the panel. This is done by the circuit that feeds the boiler, or gas range or gas dryer or furnace where the circuit wiring has a #14 or #12, 10 etc. bare or green equipment grounding conductor. BX, AC cable conduit etc could also be the equipment ground

    So the gas pipe is "bonded" to other non current carrying metal parts but is not part of the GEC.

    CSST (unless it is the newer type like "counter strike) should have a bonding jumper run across end to end to bond around the CSST.

    In some cases the older CSST was hit by lightening and couldn't carry the fault current to ground resulting in building fires.

    Some locations will have the GEC run from the meter socket (but not many) this is a POCO issue.

    Many gas meters in addition have rubber washers or gaskets to prevent the underground gas pipe from being a good ground and most of the new pipe is plastic as are the water lines.

    The method with new building is to put copper wire on the ground before the footings are poured.....makes the best ground. Ground rods although required are very poor grounds
    ChrisJ