200 amp underground service wire
Electrical experts, For 200 amp service my electrician recommended 4/0 Urd cable. I noticed the cable is made up of 4/0 4/0 and 2/0 for the neutral vs all wires being 4/0. Then I asked about 250 kcmil. Even this urd cable has 250, 250, 3/0 for neutral. Why is neutral always 2 sizes lower. Is this ok by code for neutral to be undersized? Thank you
similarly for an aluminum ser cable , that I am using for a 100 amp sub panel from 200 amp main is sized 1,1,1,3.. 3 for ground. Why is ground sized lower? In Romex, generally all wires seem to be of same gauge. Thanks for you insights.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part