hhsting
Senior Member
- Location
- Glen bunie, md, us
- Occupation
- Junior plan reviewer
Attached sketch shows 75kva transformer two secondary conductors:
1. Is 4#3/0
2. Is 4#4/0
The two panelboards are 200 MCB and 225 MCB 208/120V three phase
Question:
1. Its confusing NEC 2017 section 250.66 how does one size the grounding electrode conductor sum of 3/0 and 4/0 or based on largest which is 4/0 or something else? What code section as well?
1. Is 4#3/0
2. Is 4#4/0
The two panelboards are 200 MCB and 225 MCB 208/120V three phase
Question:
1. Its confusing NEC 2017 section 250.66 how does one size the grounding electrode conductor sum of 3/0 and 4/0 or based on largest which is 4/0 or something else? What code section as well?