I am going to run 3-#3 THHN and a #8 THHN for my grounding wire for a single phase 100a sub-panel in the same structure as the main panel . The supply house thought I should a #6 as did my father-in-law who has been an electrical contractor for 40 yrs. They are probably right but when I read table 250.122 it sure looks like it would be #8. I would appreciate it if someone could clear this up for me.
grounding wire size
- Thread starter df3557
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bphgravity
Senior Member
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- Florida
Based on your description, #8 would be compliant with the NEC. *Keep in mind the note to the table*
- Location
- New Jersey
- Occupation
- Journeyman Electrician
I agree with Bryan, but I'm curious as to why the others thought that a #6 is required?
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