Installation manual

Safety
153396 Revision D xi
This manual is for use by qualified installers only
Wiring Requirements
1. All wiring methods and materials shall be in accordance with the
National Electrical Code ANSI/NFPA 70, as well as all state and local
code requirements.
• Use copper conductors with an insulation rating of 90°C.
2. The Xantrex GT250 has a three-phase, four-wire output.
3. The Xantrex GT250 is interfaced with the AC utility grid at TB1 (TB1-A, TB1-B,
TB1-C and TB1-N), located in the lower left side of the enclosure. These
terminals require the use of a UL-approved crimp-on type ring terminal or a
UL-approved compression-type lug certified for use with the chosen
interface cables. Keep these cables together as much as possible and
ensure that all cables pass through the same knockout and conduit fittings,
allowing any inductive currents to cancel.
For torque values, see Table A-6 on page A–6. See Figure 1-3 on page 1–5
for the location of these terminals.
4. The AC neutral terminals (H0 and X0), shall be left floating (not connected)
on both the utility and inverter sides of the isolation transformer. See “Inverter
Isolation Transformer” on page 2–4 for details.
5. The Xantrex GT250 is interfaced with the DC photovoltaic array at TB3, as
well as TB4 and TB5 (PV GND), located in the lower right side of the
enclosure. Do not connect the grounded power conductor from the PV array
directly to TB5 (PV GND); doing so will bypass the ground fault detector and
violate the NEC.
6. The TB3, TB4, and TB5 terminals require the use of a UL-approved crimp-on
type ring lug or a UL-approved compression-type lug certified for use with
the chosen interface cables. Keep these cables together as much as
possible and ensure that all cables pass through the same knockout and
conduit fittings, allowing any inductive currents to cancel. For acceptable
torque values for the box style connectors and the TB3, TB4, and TB5
terminals, see Table A-7 on page A–6. See Figure 1-5 on page 1–8 and
Table 1-1 on page 1–8 for the location and polarity of these terminals.
7. This product is intended to be installed as part of a permanently grounded
electrical system as per the National Electrical Code ANSI/NFPA 70, as well
as all state and local code requirements. A copper clad earth grounding
electrode must be installed within 3 ft. (1 m) of the Xantrex GT250 enclosure.
The AC ground bus bar (TB2), located in the lower left side of the Xantrex
GT250 enclosure, must be used as the single point connection to the earth
grounding electrode for the inverter system.
8. The equipment grounds on the Xantrex GT250 are marked with
9. AC overcurrent protection for the utility interconnect (Grid-tie) must be
provided by the installers as part of the Xantrex GT250 installation.