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?
I am using a pretty big panel in my garage (SqD 20/40) and it is full with a couple tandems and a sub on for the spa. If you start out with one of those 4 high/2 wide breakers to feed the house the slots start going away fast. I still agree 42 is a lot.
It is one killer garage. He is a "Need for Speed" guy and moving part of his shop to his house. Everything seems to be small 220V and it really ate up my panel spaces. We put anything and everything you could think of this place. I am envious to say the least.