6 Commissioning
31
6
Commissioning
All NTX inverters require that PV array normally
operates in an ungrounded configuration. As
required by UL 1741 update, the GFCI protection
is active whenever there is sufficient DC voltage to
feed PV power into the utility grid in the NTX.
DANGER
Deviating from the procedure described in this
chapter could expose you to lethal voltages. Death
or serious injury will result.
Commission the NTX in the order described in the
following procedure.
1. Make sure any covering placed over the PV array
is removed.
2. Connect the grid voltage to the NTX by turning
on the main AC circuit breaker/disconnect in the
main utility panel.
3. Turn the external DC disconnect to position
“ON”.
Or
Turn the NTX internal DC disconnect to the “ON”
position.
4. If there is sufficient sunlight available, the NTX
will enter the “Waiting” mode and the green
LED will stay on steady during the system check
routine.
5. If no AC fault is detected, the NTX will enter the
“Checking” mode, and the NTX will begin to
run normally. At the same time the green LED
will keep flashing and the LCD enter the default
menu. If an AC fault was detected, the NTX will
wait five minutes prior to starting.
WARNING
If there is a ground fault in the array, the message
“GFCI Fault” will be displayed. If this messege is
encountered, turn off the DC and AC disconnects to
the inverter and trouleshoot the array.
The NTX will automatically begin to feed power to
the utility grid if there is adequate solar irradiation
and the resulting PV input voltage is greater than
150 V DC.
If the NTX is not operating as expected after com-
missioning has been completed, refer to section “7
Display and messages”, see page 32 and to section
“8 Troubleshooting”, see page 40.
WARNING
· Anytime the AC power is disconnected from
the inverter either manually or as a result of an
AC disturbance, the inverter will wait 5 min-
utes after the AC power has been restored to
reconnect.
· When servicing the inverter, always disconnect
the AC first, then the DC.