String sizing per US NEC 690.7.A.3

[solar_chris]

For PV systems in the US, this is now the standard way of computing max string length for large systems. However, I have been unable to use PVsyst for this and am therefore using SAM.

The method requires computing the Voc of the system throughout the year based on the applicable weather file. Thus it assumes that the inverter never turns on, and takes the worst 30 (or 60) minute string voltage based on the combination of irradiance and temperature. This voltage must be less that the listed max voltage of the modules and inverter.

Can this be done in PVsyst? Either directly or by somehow creating an OND file that would never turn on, and therefore UArray would be Voc. SAM will give me the Voc in the 8760 data and therefore allows use of this method.

Thanks in advance for any help.