Wire size for sub-panels

#1 copper 75c column of 310-16

#2 is "hold your nose" legal.

But, why 3 panels? Why don't you just install your first sub on the other side of the basement and feed the garage from that? Run it in 1 1/2" PVC for four #1s or even 1/0 and it is just pasting pipe.

Thanks very much for the response, Greg.

OK, that's easy enough. What size conduit should I use for that? And even though I'm connecting the two panels with metal conduit, I assume I need a separate ground wire? If so, what size?

By "hold your nose" do you mean barely legal, i.e., almost smoking?!? Is it safe?

The new garage and basement panels are in opposite directions from the main panel, 100+ feet apart. Since the main panel is full and I have to pull something out of it to make room, the extra panel right there was the best idea I could come up with. Plus, that adds a little more flexibility if I ever need to add any more circuits in that vicinity.

Thanks again, Mark

It is an excellent idea even if the code allowed the raceway to be used. You need #6 copper or bigger ground wire for 100-200a in table 250.122

Romex is supposed to be used at it's 60c column rating. #2,( the largest Romex they make) is 95a in the 60c collumn but the code says you can use it at the next higher standard breaker size (they don't make 95a breakers). It is the type of things inspectors may or may not 90-4 you on (the inspector's opinion rule) I don't think it is really particularly dangerous since romex uses a 90c conductor. The practical limit is really the temp rating of the terminals in the breaker which is 75c in the big sizes (set screw and hole lug) and 60c in smaller sizes (screw and washer terminal lug).

Great! That should be all I need - thanks again.

By the way, is table 3-16 available on-line anywhere?

Mark