For one reason or another Section 230 has always given me trouble. I have never fully understood it and am looking for some clarification. I am wiring a detached garage and upgrading an existing 200A service to a 400A all-in-one. One main 200A breaker will supply the main house with the other 200A main supplying a 200A 40/42 space 3R subpanel at the detached garage. The problem I am having is that 42 spaces is not enough. With all the circuits in the garage I am still under on the load calcs but over on the breaker spaces. Can I feed an additional subpanel from my 200A subpanel?