8-AWG in PVC Conduit

[jeff48356]

Suppose I'm running 40A service out to a detached garage about 25 feet away from the house. I run #8-3 NM-B cable through the basement to a junction box where it will connect to wires going into a PVC conduit out to a service panel in the garage. Since the three conductors (black, white, red) would need to be #8, would it be OK to use #10 for the ground (green wire)? Or would that need to be #8 as well? The ground wire in the 8-3 cable is #10.

 

[infinity]

Since you're using #8 at 40 amps, IMO the size EGC listed in 250.122 (#10) would be sufficent.

 

[jeff48356]

OK, thanks!

 

[fmtjfw]

Can't use NM

Can't use NM

If it is an underground feed or exposed conduit, you can not use NM cable. NM is not rated for wet conditions and conduit installed underground or conduit installed in a wet location (outside) is considered a wet location. You must use wire rated for a wet location.

 

[stickboy1375]

If it is an underground feed or exposed conduit, you can not use NM cable. NM is not rated for wet conditions and conduit installed underground or conduit installed in a wet location (outside) is considered a wet location. You must use wire rated for a wet location.

That's not what was posted, nor question at hand...