GECs at Separate Structures Fed Verification

[tryinghard]

In my scenario below structures 1-2 include #8cu GEC/bonding jumpers based on feeder size; these aren?t required to be larger are they (I don?t see it if so)?

Electrodes at structure 1 = 1600A service disconnect (SWG) with GEC/bonding jumper:
1- CEE, 3/0 cu
2- Metal frame, 3/0 cu
3- Rods, 6 cu
Electrodes at structure 2 = 125A feeder (#2's) with GEC/bonding jumper:
1- CEE, 8 cu
2- Metal frame, 8 cu
Electrodes at structure 3 = 80A feeder (#4's) with GEC/bonding jumper:
1- CEE, 8 cu
2- Metal frame, 8 cu

In keeping with:
250.32.B (sized per 250.122 for grounding or bonding of equipment, structures, frames?required)
250.50 (related electrodes connected that are served ? not fed)
250.53.C
250.66

 

[tryinghard]

In my scenario below structures 2-3 include #8cu GEC/bonding jumpers based on feeder size; these aren?t required to be larger are they (I don?t see it if so)?

Electrodes at structure 1 = 1600A service disconnect (SWG) with GEC/bonding jumper:
1- CEE, 3/0 cu
2- Metal frame, 3/0 cu
3- Rods, 6 cu
Electrodes at structure 2 = 125A feeder (#2's) with GEC/bonding jumper:
1- CEE, 8 cu
2- Metal frame, 8 cu
Electrodes at structure 3 = 80A feeder (#4's) with GEC/bonding jumper:
1- CEE, 8 cu
2- Metal frame, 8 cu

In keeping with:
250.32.B (sized per 250.122 for grounding or bonding of equipment, structures, frames?required)
250.50 (related electrodes connected that are served ? not fed)
250.53.C
250.66

 

[petersonra]

I would point out that CEEs never require more then a #4 GEC.

 

[tryinghard]

Bob,

Got it, they can be smaller though base on feeder or service size. I was really trying to varify this scenario is three differant grounding electrode systems that interconnect only via EGC

 

[petersonra]

Bob,

Got it, they can be smaller though base on feeder or service size. I was really trying to varify this scenario is three differant grounding electrode systems that interconnect only via EGC

However, it might well be more cost effective to run a larger wire and avoid having to run some kind of physical protection like EMT which would require bonding bushings. I think #4 and larger can be run without extra protection, but smaller GECs require physical protection of some sort.

 

[tryinghard]

True and these are stubs so there's not quite as much but this is worth considering. To me 250.64.B is strangely worded but looks like #8 and smaller need protection.