Add another string Enphase M215 to a separate subpanel?

Re: Add another string Enphase M215 to a separate subpanel?

vsheetz wrote: »

Scenario: two existing strings of Enphase M215 microinverters connected to the main breaker panel via a combiner box - this at one end of long rectangular house. Future room addition at other end of house, which will have a breaker subpanel there. If mounting another string of Enphase M215's on the room addition, can the additional string be connected to the subpanel rather than wiring all the way back to the combiner box?

Assuming that all of the requirements for DC and AC disconnects are met, the main thing you will have to look at are the current ratings of the sub panel bus and the main breaker of the sub panel. (Called the 120% rule.)
The AHJ may have a concern about requiring two disconnect at opposite ends of the house to totally shut down the PV. You may be able to use a switch and contactor (relay) to disconnect the new string from the subpanel.

You may find it easier and cheaper in the end to run new conduit to the combiner.