250.64(C), Another Electrode & GEC

[tryinghard]

Is the size of the bus bar ever an issue when terminating in the distribution/panel/switchgear to additional electrodes?

We have an existing concrete building with a CEE, a metal building was added later on top with no record of bonding its frame. Now a transformer is added and the building frame would normally be the electrode. There is no simple route to the building frame for its bond to the CEE but it can terminate at the same location as the existing GEC on the service disconnects bus, would you say this is this compatible with 250.52(A)(2) & 250.64(C)?

 

[bphgravity]

Yes..........

 

[tryinghard]

I believe I just figured out my issue. The fact is we are adding another grounding electrode, metal frame of building type, and this must bond to the existing. Here is the trail I took to find this.

250.52, Electrodes
1 – Existing is CEE, 250.52(A)(3)
2 – New is Metal Frame of Building, 250.52(A)(2) & 2

250.50 & 250.58, Common grounding electrode system because two electrodes will be used.

250.53(C), Grounding electrode, bonding jumper, “shall be installed in accordance with 250.64(A), (B), & (E), no mention of (C) – I just noticed this so I now understand the bus size does not matter.

In this light electrodes can be added later (past initial installation) and be effectively bonded together via through the GEC’s destination termination rather than at the actual original electrode.

The new grounding electrode bonding jumper does not even have to be continuous like a GEC, it can route to ground buses in switchgear and panelboards.