Thanks for your reply, GoldDigger.
In the garage, there's a new Murray 150 amp subpanel. On the panel sticker, it says "Back-Fed Breaker Requires Hold-Down Kit MBR2M". Is it safe to assume since I'm putting in a back-fed PV breaker, the installer would need this kit? Or am I misunderstanding something? (I'm a designer, but this a piece of information I'd like to know nonetheless)
The main panel is an MLO being fed by 1/0 copper service entrance conductors. It lacks a sticker that tells me the busbar rating of the panel, but there's a single 125 amp subpanel breaker on the bus (which feeds the subpanel in the garage). For the sake of this conversation, I will assume the busbar rating of the main panel is 125 amps.
From a 120% Rule point-of-view, would this be the correct way to think of the calculations:
Subpanel: (150A * 120%) - 125A = 55A of available PV amperage
Main Panel: Since it's a MLO panel, I can have PV amperage up to the limit of the service entrance conductors
Is my way of reasoning correct?
Thanks in advance.
Kind Regards,
Andy