How many strings of modules can I install?

SolarAPP does not restrict the total number of strings per project. All DC circuits must have the same construction, per the checklist, regardless of the number of connected modules.  Each DC pair of conductors must land on their own input port per the manufacturer's instructions.

For Microinverters and AC modules, SolarAPP does not restrict the number of branch circuits.  The total inverter output is used to determine applicable ratings for combiner panels, combined overcurrent protective device, and interconnection calculations.  All branch circuits must have the same construction, per the checklist, regardless of the number of connected modules.  

Contractors may only combine up to (2) DC series-connected strings of modules, in parallel, on the roof, and use a single pair of conductors from the rooftop array to a central inverter. SolarAPP uses this question to reference the appropriate wire size table, taking into account the parallel current of DC series strings.  

The code requires that if (3) or more DC series-connected strings are combined in parallel, that fusing is included for each string. SolarAPP cannot verify code compliance relative to DC fusing requirements and these systems are not eligible to use SolarAPP+.  Projects configured in this manner must be permitted through the traditional permitting process.