Xantrex Technology GT3.0 - Manual (Page 34)

Installation
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Voltage and MPPT Requirements
MPPT operational
window Ensure that the PV array used in the system operates within the MPPT operational
window (Table 2-1).
Voltage
requirements The maximum power point voltage of a string connected to the GT Inverter should
be a minimum of 195 Vdc. If it is less than 195 Vdc, then the power point is
shifted and the PV voltage is regulated to 195 Vdc.
By regulating the operating voltage of the solar modules, the MPPT software
maximizes their output energy.
Effects of array voltages outside of the MPPT operational window are shown in
Table 2-1.
Maximum PV
Power The solar array should be sized such that its maximum power output does not
exceed the limits of the MPPT operational window (195 to 550 Vdc). See
“Guidelines for Matching PV Array Size to Xantrex Grid Tie Solar Inverter
Input”.
Under no conditions should the array voltage exceed 600 V
OC
(open circuit
voltage).
Table 2-1 MPPT Operational Window
Voltage Effect of Array Voltage Inverter Mode
< 195 Vdc Operating voltage will be shifted to 195 Vdc;
the array will not be at its maximum power
point Low power
195 to 550 Vdc Maximum harvest of solar energy MPPT window
550 to 600 Vdc Will not allow maximum harvest of solar
energy Power derating
> 600 Will shut down and may cause damage to the
inverter; stops selling surplus energy Shutdown