Planning the Installation

Guidelines for Matching PV Array Size to Xantrex Grid Tie Solar Inverter Input

For determining the number of panels required in the PV string (panels connected in series), you must ensure that the following three requirements are met:

1.To avoid damage to the inverter, ensure that the PV array output will never exceed 600 Vdc under any conditions.

2.Do not exceed the maximum array short circuit-current rating marked on the inverter.

3.To achieve maximum energy harvest from your array, ensure that the VMP (voltage at maximum power) does not drop below 195 Vdc or increase above 550 Vdc under most conditions.

Guidelines to help you meet these requirements:

•Consider the expected VOC of the string under all possible conditions. The panel manufacturer provides a VOC rating per panel, but it is usually rated at 25 °C (77 °F). Ensure that the VOC rating at the coldest ambient temperature does not exceed 600 VOC. Panel voltage increases in cold temperatures—the panel manufacturer should be able to provide a coefficient of voltage increase per degree.

•Panel voltage decreases in high temperatures. This will affect the panels’ VMP. Again, the manufacturer’s coefficient must be used with the highest expected temperature to determine the minimum VMP.

Once you know the specifications of your panels, all these factors will help determine the maximum and minimum number of panels that can be used.

Visit the Support page at www.xantrex.com to use an online PV array sizing tool.

Grounding Requirements

WARNING: Shock hazard

The GT Inverter must be grounded by connection to a grounded permanent wiring system.

AC Grounding

AC grounding is governed by local codes. Consult the local utility for specific grounding requirements.

DC Grounding

The GT Inverter is designed to work with ungrounded PV arrays.

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