Installation
Voltage and MPPT Requirements
MPPT operational | The MPPT software maximizes the output energy of solar arrays as long as the | ||||
window | operating voltage is within the MPPT operational window. Ensure that the PV | ||||
| array used in the system operates within the MPPT operational window. | ||||
| Effects of array voltages outside of the MPPT operational window are shown in | ||||
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| Table |
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| Voltage |
| Effect of Array Voltage |
| Inverter Mode |
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| < 195 Vdc |
| Operating voltage will be shifted to 195 Vdc; |
| Low power |
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| the array will not be at its maximum power |
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| 195 to 550 Vdc |
| Maximum harvest of solar energy |
| MPPT window |
| 550 to 600 Vdc |
| Will not allow maximum harvest of solar |
| Power derating |
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| energy |
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| > 600 |
| Will shut down and may cause damage to the |
| Shutdown |
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| inverter; stops selling surplus energy |
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Voltage | The maximum power point voltage of a string connected to the GT Inverter should | ||||
requirements | be a minimum of 195 Vdc. If it is less than 195 Vdc, the inverter will continue to | ||||
| operate, but it will regulate the PV voltage to 195 V. Because the array will not be | ||||
| operating at its maximum power point, this may result in lower than expected | ||||
| energy harvest. |
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Maximum PV | The solar array should be sized such that its maximum power output does not | ||||
Power | 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 | ||||
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The array voltage should never exceed 600 VOC (open circuit voltage) under any thermal condition.
Likewise, ensure that the Isc (short circuit current) rating of the array at any temperature does not exceed the short circuit current rating of the inverter.