250.104 (B)

[ceb58]

Replacing an old 100 amp service on a house with a 200 amp meter combo. I am going to feed the indoor panel, which is now a sub, with a 100 amp breaker in the combo. The house has NG lines ran in 3/4 black pipe and have never been bonded. I want to check to make sure I am right on this 250.104(B) states

The bonding conductor(s) or 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 circuits would be from the 100 amp panel so by that I can use a #8 to bond the gas line. Correct? There is nothing else going to come from the combo to the house. They wanted the combo put in to feed a garage that will be built away from the house soon.

 

[Dennis Alwon]

The black iron pipes don't need any bonding if there is a circuit feeding the appliance that uses the gas. For example the furnace equipment grounding conductor will be sufficient to bond the lines. If there is no gas appliance that is served with electric then you have to bond from the service panel and then you would need to size it to 250.66

 

[ceb58]

The black iron pipes don't need any bonding if there is a circuit feeding the appliance that uses the gas. For example the furnace equipment grounding conductor will be sufficient to bond the lines. If there is no gas appliance that is served with electric then you have to bond from the service panel and then you would need to size it to 250.66

Good, there is a water heater with electronic igniter and a 3 ton gas pack.

 

[Gregg Harris]

250.104(B)
(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 the service equipment enclosure; the grounded conductor at the service; the grounding electrode conductor, if of sufficient size; or to one or more grounding electrodes used. The bonding conductor(s) or 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.

New testing data learned from the independent studies being done for the bonding of CSST shows that the grounding conductor used in #14 and #12 is insufficient for bonding the gas piping attached to the appliance.