quick question

[SpArKs12]

A 200A feeder for an outbuilding uses 500 kcmil USE ungrounded aluminum conductors. The min size copper equipment grounding conductor run w/ the feeder is:

#2
#3
#4
#6

Now my question is since they didn't state any temp requirements I would go to the 60 degree column in 310.16, and find that a 200 A feeder in aluminum would require only a 350 kcmil. So maybe they had to increase size for VD, does that mean I need to increase my copper ground 2 sizes as well making it a #2?

 

[augie47]

My thoughts would be a 200 amp feeder, without calculated load, would require a 200 amp conductor. With 200 amp normally being a 75 deg. termination, that would be a 250 AL. Since they ran a 500 kcmil that 2X the norm. A normal 200 amp EGC in Cu would be a #6 at 26.240 cmil x 2 would require 52480 or a #3 Cu.