Solar Array Series String Sizing & MPPT Calculator

Compute minimum and maximum modules per series string to satisfy inverter MPPT voltage limits and NEC 690.7 cold-weather maximum voltage constraints.

STC Open-Circuit V_oc (V):

STC MPP Voltage V_mp (V):

Temp Coeff of V_oc β (%/°C):

Temp Coeff of V_mp (%/°C):

Max DC Volts (V): 600V res, 1000V/1500V comm

MPPT Min (V):

MPPT Max (V):

Extreme Low Temp T_min (°C): Record winter minimum (ASHRAE)

Max Summer Ambient T_max (°C):

Optimal Series String Range

Max String Voc (Cold)

Cold Module V_oc

Hot Module V_mp

Inverter Window

NEC 690.7 Compliance & MPPT Tracking

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