EGC sizing

[Leespark57]

Hey, I'm struggling to remember something. If we have a 10 hp, 3-phase, 208-volt motor (FLC 30.8 x 125% = 38.5A) installed on a 70-amp inverse time breaker (250% of FLC) using #8 MC cable with a #10 equipment ground, would it be a violation given that T250.122 requires a minimum #8 equipment ground?
Thanks

 

[jap]

At a glance I'd say yes it's a violation.

JAP>

 

[Leespark57]

Another example would be #6 MC cable (65 amps 75 degree) on a 70 amp breaker. Would that also be a violation? It's just something to keep in mind, I guess.

 

[jap]

If you're dead set on using MC cable, I'd suggest using the type with a full size EGC.
I've never used MC cable for a flexible motor connection.

Jap>

 

[Leespark57]

If you're dead set on using MC cable, I'd suggest using the type with a full size EGC.
I've never used MC cable for a flexible motor connection.

Jap>

Definitely. Thanks