Can the outputs of two or more SB2500 inverters be combined in a junction box into a single set of conductors that then terminate on a single circuit breaker in the panelboard. Or must separate conductors be run from each inverter output to dedicated separate circuit breakers in the panelboard.

NEC 690-64 addresses connection of photovoltaic power sources; NEC 690-64(B)(1) (which deals with load side connections) says "Each source interconnection shall be made at a dedicated circuit breaker or fusible disconnecting means."

I would read this as requiring a separate circuit breaker for each SB 2500, but I also think that a sub-panel with breakers for each SB could be used, if you really had to have a single 230v circuit run. Of course, the NEC also says that "... circuit breakers, if backfed, shall be identified for such operation" so you would need to think about this at both the main and sub-panels.

Sounds like you might have a long run planned, make sure you keep in mind the importance of a low grid impedance to the Sunny Boys & factor that into your choice of wire sizes.

-Roger [img]images/smiles/icon_biggrin.gif[/img] [img]images/smiles/icon_biggrin.gif[/img]

On my drawing, I put a sub panel as Roger suggested, and the boys behind the counter at city hall approved it. I think it's sensible. I hope the field inspector doesn't squawk about it.

Do you feel the price of the sub-panel and three(?) breakers was less than the cost of a second run of wires?