Bonding Jumper Size

[Neal Lewis]

Is the minimum size for the bonding jumper #6 copper for a 100 amp service?

The solid aluminum jumper in the photo looks to be about #10.

Thanks

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[Bill Kibbel]

I think it's a minimum of #8 copper if protected, #6 if not and a minimum of #6 aluminum.

[Richard Moore]

If I'm reading my "bible" correctly, the size is from table 250.66 and is actually dependant on the size of the largest SEC's, rather than final service size. Assuming you have "normal" SECs for a 100-amp service the bonding conductor should be the minimum size from the table...#8 copper or #6 aluminum.

I have a hard time judging size from photos, but that looks a bit bigger than a #10.