250.52(3)

[Buck Parrish]

If I use a ufer ground (concrete encased rebar 20ft or more).
Do I need to use grd. rods?
And is #4 cu good for a 400 amp service?

This is residential sfd

 

[raider1]

No, you would not need to use ground rods unless the ground rods are present.

Chris

 

[eprice]

If I use a ufer ground (concrete encased rebar 20ft or more).
Do I need to use grd. rods?

no

And is #4 cu good for a 400 amp service?

This is residential sfd

yes

Note: these are NEC answers. An engineer may spec something in excess of the NEC requirement.

Edit: Actually, I guess there aren't many electrical engineers designing single family dwellings

 

[raider1]

If I use a ufer ground (concrete encased rebar 20ft or more).

And is #4 cu good for a 400 amp service?

This is residential sfd

Where the grounding electrode system consists of just a CEE then you need not run anything larger than a #4 to the CEE regardless of the service size. (See 250.66(B))

Chris

 

[Buck Parrish]

Thanks, that's what I thought...