The following question is not for the squeamish.
High Resistance Ground System and the application of ground conductors in pvc conduit from transformer to power distribution center
High Resistance Ground System and the application of ground conductors in pvc conduit from transformer to power distribution center
We have a separately derived 480 wye connected secondary feeding the load side of a power distribution center (PDC) 4000A main disconnect. The system is using a Post Glover HRG installed remote from the PDC. The HRG will restrict current at 277V to <10A.
The HRG is connected with the "Grounding Electrode Conductor" at one end - and the X0 bushing "grounded system conductor" run isolated and connected at the opposite resistor end.
An Equipment Bonding Jumper connects the GEC resistor end to the PDC ground bus.
There is a 4/0 ground loop connection that bonds the transformer tank to the PDC ground bus.
We have 10 parallel feeders or "derived phase conductors" routed n buried PVC conduits.
I am having trouble justifying what ground related conductor is required to be in the conduit with the derived phase conductors and how to size them. I maintain that this conductor is considered a supply side jumper.
Can these derived phase conductors be run without a ground conductor in each conduit?
Does 250.122 apply as I have heard suggested? are these truly an equipment grounding conductors? (solution 500kcmil?)
Does 250.66 apply as per 250.36 (G)? The conductor in question are technically not an "Equipment Bonding Jumper". The (EBJ) is the link from the grounded resistor end to the PDC ground bus. (solution 1/0 or greater?)
Does 250.102 apply? this may seem to be the proper NECpath. (solution 1/0?)
Can anyone describe the condition where more than 5-10A will flow in this conductor?
Any help understanding this animal would be greatly appreciated!
Thanks!
The HRG is connected with the "Grounding Electrode Conductor" at one end - and the X0 bushing "grounded system conductor" run isolated and connected at the opposite resistor end.
An Equipment Bonding Jumper connects the GEC resistor end to the PDC ground bus.
There is a 4/0 ground loop connection that bonds the transformer tank to the PDC ground bus.
We have 10 parallel feeders or "derived phase conductors" routed n buried PVC conduits.
I am having trouble justifying what ground related conductor is required to be in the conduit with the derived phase conductors and how to size them. I maintain that this conductor is considered a supply side jumper.
Can these derived phase conductors be run without a ground conductor in each conduit?
Does 250.122 apply as I have heard suggested? are these truly an equipment grounding conductors? (solution 500kcmil?)
Does 250.66 apply as per 250.36 (G)? The conductor in question are technically not an "Equipment Bonding Jumper". The (EBJ) is the link from the grounded resistor end to the PDC ground bus. (solution 1/0 or greater?)
Does 250.102 apply? this may seem to be the proper NECpath. (solution 1/0?)
Can anyone describe the condition where more than 5-10A will flow in this conductor?
Any help understanding this animal would be greatly appreciated!
Thanks!