Xantrex Technology GT3.0 - Manual (Page 36)

Installation
2–8 975-0131-01-01
Grounding Requirements
AC Grounding
North America The GT Inverter must be connected to a grounded, permanent wiring system.
The negative PV conductor must be bonded to the grounding system at only one
point in the system, through the internal Ground Fault Detection circuit.
See Figure 2-2 for the location of the GT Inverter ground bar.
Elsewhere In other locations, AC grounding is governed by local codes. Consult with the
local utility for specific grounding requirements.
PV Grounding
In North America, PV arrays are required to be connected to earth ground; in
Europe they are not. PV Ground Fault Protection (PVGFP) is required in North
America for roof-mounted PV arrays.
The GT Inverter is designed to have all PV positive, negative, and ground
conductors connected inside its wiring box. The PV equipment ground should be
connected to the GT Inverter ground bar. This ground bar must also be connected
to the main utility breaker panel ground bar and to the house grounding rod
according to NEC requirements (see Figure 2-2).
The size for the conductor is usually based on the size of the largest conductor in
the DC system.
Long Distance Grounding
If the PV array is more than 30 m (100 feet) from the inverter, then there must also
be a direct connection from the array frame to an earth ground next to the array. A
connection between this ground and the building ground connection via a buried
wire between the two points is also necessary (see Figure 2-3).
Lightning Protection
Reduce the risk of lightning damage by using a single-point grounding system. In
this system, all ground lines terminate at the same point. This point normally is the
main utility ground installed by the utility company to provide a ground for the
house wiring (see Figure 2-4). This ground usually consists of a copper rod driven
1.5 to 2.5 meters (6 to 8 feet) into the earth.
WARNING: Shock hazard
The GT Inverter must be grounded by connection to a grounded permanent wiring system.