LD1
Epic Contributor
I don't think copper and aluminum have the same current carrying characteristics. Usually have to upsize for aluminum.
Let me start by saying I am NOT an electrician so I may be wrong BUT
I do believe you are correct and grsthegreat is wrong here.
When I built by barn, I used what the local COOP uses for their 100 Amp service, which is 1/0 underground. Which has 1/0 AL wire for the conductors and #2 AL forthe neutral. My choices were either this 1/0, 1/0, #2 Aluminum wire OR 2/2/4 copper wire. obviously the copper was ore expensive.
For 200A installs with aluminum wire they use 4/0 with 2/0 for the Neutral.
#2 aluminum xhhw is only rated @ 90A. I personally would not want to use that for 100A service. #2 copper would be okay though.
Again, I am no electrician, but I can read a chart Ampacity Charts