GEC's On EGC Bars - Not Service Neutral Bar

[dtontarski]

My understanding is that the grounding electrode conductors should be connected on the same bus which the grounded service conductor (service neutral) is connected to. The GEC's in this panel are terminated on this panel's 2-bonded equipment ground bars.

(one GEC is clamped to the copper municipal supply line, and the other to a driven rod)

I just want to make certain that I am correct in calling this out, and of course to have this discussed here so that others can benefit.

Click to Enlarge

69.63?KB

[Jim Katen]

I believe that the applicable article is 250.24(A)(4). As I read it, you're not supposed to rely on the screw as a bonding jumper in this case. You'd need a properly sized wire between the neutral terminal bar and the equipment grounding bar.

Alternatively, you could run the GEC right to the neutral bar with an appropriate accessory lug.

[dtontarski]

Thanks Jim.

Would it suffice to have just one of these GEC's connected to the neutral terminal bar on an appropriate lug (one is present) or with an appropriate sized wire, or would both of these be required to be terminated on this bar?

[Jim Katen]

Thanks Jim.

Would it suffice to have just one of these GEC's connected to the neutral terminal bar on an appropriate lug (one is present) or with an appropriate sized wire, or would both of these be required to be terminated on this bar?

If they go to different parts of the grounding electrode system - for instance one goes to a set of driven rods and the other goes to a water supply pipe - then they should both be connected to the neutral conductor with a terminal bar or a wire - not a screw.

[brric]

The GECs should have been terminated next to the grounded service conductor at the top center of the load center. Lug screws are provided there.