.66.
.67.
8. Troubleshooting
Alarms
Cause
Solution
• Inverter detects grid
instability, internal fault
current high
GRID-INTF:
Grid unstable
Test – With DC Switch OFF
• Measure AC voltage
• Test AC line for THD
• Test – With DC Switch ON
Test AC line for THD
• Multiple inverters/turn one off
• Impedance matching adjustment or box
• Internal damage
• Wire came loose in shipping
INI-FAULT:
Initialization
Protection
• Master and Slave DSP
have different values
Reset Inverter
• DC switch OFF
• Wait until all lights/LCD turn off
• DC switch ON
• Replace inverter
OV-TEM:
Temperature
Protection
• Inverter detects high
ambient temperature >60C
Inspect installation
• Check heatsink for obstructions/ventilation
• Is inverter in direct sunshine
• Measure ambient temperature near inverter
• If temp is in range replace inverter
PV ISO-PRO
01/02:
Ground
Protection
• Inverter detects low DC
insulation resistance
Inspect installation
• Reset inverter
• Note weather conditions when alarm occurs
• Measure insulation resistance
• If normal, measure in SAME weather as alarm
• Physically check cables
• Replace inverter
ARC-FAULT
• Inverter detects arc
in DC circuit
Inspect installation
• Check cable with string tester
• Physically check cables
• Inspect panel junction boxes
• Inspect cable connections
• Reset inverter
• Replace inverter
Table 8.1 Fault messages and descriptions
Screen OFF
with DC applied
• Inverter internally
damaged
• Do not turn off the DC switches as it may
damage the inverter.
Please wait for sunset and confirm the string
•
current is less than 0.5A with a clip-on ammeter
and then turn off the DC switch. String current
above 0.5A is under load.
• Note: Damage due to wrong connections or fire
caused by removing string wires or opening
fuse holders under load is not covered in the
device warranty.
Alarms
Cause
Solution
• Inverter detects grid
Frequency as too high
OV-G-F: Over
Grid Frequency
Test – DC switch OFF
• Check frequency at the inverter test points
• If Frequency measures high, adjust upper
limit with permission from utility
• Check LCD reading, may be a bad
measurement circuit
Test – DC Switch ON
• Check grid standard
• Replace inverter
NO-GRID
• Inverter does not
detect the grid
Test – DC switch OFF
• Check AC at the inverter test points
• L-L, L-GND
• Check LCD reading, may be a bad
measurement circuit
Test – DC Switch ON
• Check grid standard
• Replace inverter
OV-DC: DC
voltage is too
high
• Inverter detects High DCV
Test – DC switch OFF
• Check DC at the inverter test points
• If DCV is high, too many panels in the string
Test – DC Switch ON
• Check LCD reading, may be a bad
measurement circuit
• Replace inverter
OV-BUS: DC
BUS voltage is
too high
• Inverter detects High
DCV on internal bus
Test
• Measure DC and AC voltages
• Compare with LCD
• Replace Inverter
• Internal damage
• Wire came loose during shipping
UN-BUS: DC
BUS voltage is
too low
• Inverter detects low DCV
on internal bus
Test
• Measure DC and AC voltages
• Compare with LCD
• Replace Inverter
• Internal damage
• Wire came loose during shipping
8. Troubleshooting
