Let's try to stay focused on the question. Yes it is for a single family home of 8000 square feet and they have alot going on like hot tubs and steamers and....... Load calc would be around 335 but the owner wants more. The big question is whether 4/0 AL XHHW 75 dgree C in 4 runs through a CT, bonded together in the CT as required by the local electic company is sized appropriately?