Installation and Operation Manual (Rev E)
SGI Series Inverters
DOCR-060371
31
5.0 Commissioning the Inverter PV System
At this point the inverter should be mounted, all connections are made and the inverter is
ready for power to be applied.
NOTE:
Make sure all tools, parts, etc. are removed from the vicinity of the inverter
before turning on.
WARNING:
Make a final check of all AC and DC wiring to the inverter and in the
system before turning on.
NOTE:
With the PV modules connected and inverter disconnects still off, perform a
final check of the PV voltage and polarity once more using a digital volt meter and
probing the positive (+) and negative (-) PV connections. Verify clockwise AC phase
rotation for L1, L2, L3 using a phase rotation meter.
5.1
Turning on the Inverter
Turn on the dedicated three-phase circuit breaker or disconnect at the building service.
Turn on the inverter’s DC disconnect using the handle on the front door.
Turn on the inverter’s three-phase AC breaker using the handle on the front door.
Watch the LED indicators for initialization (green and red LEDs on), then a slow blinking
green LED followed by a faster blinking green LED. Watch the LCD display for prompts
and system status.
Listen for contactor closing (inverter on-line).
Listen for slight 60 Hz hum (transformer on-line).
Following the blinking green LED and high frequency switching sound you should see a
solid green LED. This confirms that the inverter is operating normally. The LCD display
will show the AC Power (PAC), Energy (EAC), current and voltage as well as DC voltage.
5.2
Operation
The control electronics will be active as soon as the DC voltage reaches 300VDC. The inverter
will go on-line with the utility three-phase grid when the DC voltage first exceeds 390VDC
(strike voltage). Next, the inverter will load the array, bringing the DC voltage down from
390VDC to not less than 300VDC, unless the low voltage option has been selected, in which
case the strike voltage will be 370VDC and the minimum MPPT voltage will be 285VDC.
Once there is enough PV power to back feed three-phase AC power, power switching will
automatically feed power to the grid.
5.3
Turning off the Inverter
If possible, use the keypad to temporarily disable the power output.
Turn off the inverter’s DC disconnect using the handle on the front door.
Turn off the inverter’s three-phase AC breaker using the handle on the front door.
Wait at least one minute for the capacitor bank to discharge.