There is no difference between a main breaker in a subpanel and a load breaker in a main panel feeding a MLO subpanel. It's the breaker protecting the busbar of the subpanel in either case.
What is the 60A backfeed number coming from? Is that 125% of your inverter current?
Yes solar backfeed
I’m talking about the 60 amp solar backfeed in subpanel 120% only allows 50 amp back feed.
Just to be clear, if you use 60A of "solar backfeed" for the 120% rule calculation (or any other Article 705 calculation), that means that your maximum inverter output current is 48A.
Or other options may be
Whichever he does, the requirements of 705.12 also apply to the main panel, of course. IIRC he has a 200A panel with a 225A bus, so he has 70A of headroom on the main panel bus.
A 250A buss loadcenter with a 200A main, and bus terminal/tabs located on the end opposite from the main that would accommodate another 100A (main) breaker would also work.
Honestly if they sold the 225A busbars with 175A main breakers that would be enough. That would allow 76A backfeed on a 100A breaker. In my experience very few people really need 200A from their utility. I realize the psychology of selling 175A instead of 200A won't work. It's too bad.
For most inverters I think you are right, and agree that most people don't need 200A main. But Sol-Ark makes the 15K now, and it has Icc as 62.5A x 1.25 = 78.13A, for an 80A breaker. What would be nice is if loadcenter manufacturers would offer field-replaceable busbars with slightly higher capacity and at a fair price. May be another revenue stream for them.
Yeah my suggestion would accommodate that Sol Ark. The 76A is before the 125% factor.
My bad.
Why max it out at one ? my 300a busbar suggestion would accommodate two of them
