repost

[hhsting]

Sorry for reposting already closed thread but that sketch previous post maybe not clear and just want to make sure.


Attached sketch shows main service disconnect with grounding electrode conductor to external bus. The external bus has bonding jumper to steel, bonding jumper to water pipe, bonding jumper to underground metallic gas pipe and other metal pipe.


Is the underground metallic gas pipe used as grounding electrode?

 

[tom baker]

I see why you are confused. The drawing uses incorrrect terminology.
Bonding jumpers are called Equipment Grounding conductors. There should be a GEC.
I would send the dwgs back and have corrected.
3/0 to rebar, largest required is #4.... its ok , just a lot of additional cost. With all that 3/0 maybe the copper development association consulted on this.
But hey, no ground rods!

 

[LarryFine]

Is the underground metallic gas pipe used as grounding electrode?

No. The intention is to make sure the supply side of any internal piping is at the same potential as the gas appliances.

This bonding is usually done to make sure nearby lightning strikes don't cause voltage across lengths of CSST tubing.

 

[Fred B]

This print is not showing the "gas pipe and other metal piping systems" as a grounding electrode. The prints are showing an ufer ground and maybe an auxiliary of the main water pipe, the other connections are mearly bonding connections. All within code stipulations.
Print Notation is of gas pipe and other metal piping systems "in and on structure". There is no reference of underground gas pipe on print.
Side note: around here the POCO's are using a high pressure PE plastic pipe for gas supply and elbow up with metal to meter. No potential as a grounding electrode possible. Mine was installled using a horizontal boring machines, neet process.

........
3/0 to rebar, largest required is #4.... its ok , just a lot of additional cost. With all that 3/0 maybe the copper development association consulted on this.
..........

With print's reference to using 3/0 this design seems to be for a larger installation (higher voltages) it would appear you are dealing with a service of at least, backing it out using table 250.122, is up to 1200 amps and using table 250.66 service conductors of larger than 1100 kcmil, in order to require a 3/0 for EGC, don't know if this is the case only based on what is there but it would be a way that a requirement for such a large EGC.

I see why you are confused. The drawing uses incorrrect terminology.
Bonding jumpers are called Equipment Grounding conductors. There should be a GEC.
I would send the dwgs back and have corrected.
...............

Connections between (2 and 5) and between (5 and 6,4) should be marked as GEC the others are EGC. This is a common misidentification see Article 100 definitions. Only recognizing as I just got hung up on it recently.

 

[mwm1752]

Looks like an electrode/bonding system but why do you need to bond steel gas piping with 3/0? the gas steel piping is bonded through the branch circuits based upon the OCPD serving the appliance. Does this project have CSST used as branch piping? If so then the manufacture & fuel gas code would require additional bonding. Since the gas piping is not in series with the electrode path I do not believe it is considered as an electrode in this system. Yes the terminology is incorrect for the conductors.