Requirements start adding up fast in big houses with 5 ton A/C units, electric kitchens, spas and electric water heaters, even tank style. I had to use the optional calculation to get in under 200a when I put on my addition. The reality is I doubt I use much more than 100 at any given time but I suppose there are peaks. It is better to have it and not need it than to need it and not have it. I just didn't want to go through the hassle of a 320a upgrade.
The PoCo was probably going to leave my 2ga drop up there anyway even if I had to snake in a 350 MCM SE conductor set.
