21
Islanding Protection
The inverter will shut down when the power from the grid becomes abnormal or fails. This will provide safety to the
people working on the power lines and protect the home circuits and solar power inverter.
The solar power inverter continually monitors the voltage and frequency of the grid through an internal control circuit. It
will detect an abnormal condition or failure of the grid. Abnormal conditions include AC overvoltage, AC undervoltage,
AC overfrequency, and AC underfrequency. The solar power inverter shuts down and disconnects from the grid should
any of the above conditions occur.
Per AS 4777, the solar power inverter will stop within 2 seconds should the grid voltage be lower than 210 V
AC
or higher
than 255 V
AC
. The solar power inverter will stop within 1 second should the frequency of the grid be lower than 47 Hz or
higher than 53 Hz.
The solar power inverter incorporates two functions to detect and prevent islanding operation. This is important when
the output of the inverter and the power consumption of the home are well balanced and the voltage or the frequency of
the grid does not change during a power failure, resulting in the power failure not detected. If this occurs, a passive
system that detects a jumping voltage phase and an active system that detects frequency shift that stops the inverter
operation within 2 seconds.
The solar power inverter display indicates utility abnormal to indicate a power failure.
Error / Fault Code List
Type
Code
Items
Utility abnormal
F-00
Utility over-voltage
F-01
Utility under-voltage
F-02
Utility frequency over
F-03
Utility frequency under
F-06
Anti-islanding (frequency over)
F-07
Anti-islanding (frequency under)
F-08
Miss utility synchronal lock signal
F-09
Freq. abnormal (50<->60 Hz)
PV array abnormal
PV array under voltage (<60 V)
P-11
PV array over voltage (>320 V)
Inverter abnormal
E15
d-15
Relay sticking
E16
d-16
Communication
error
E17
d-17
Aux-power abnormal
E18
Ground fault
d-20
Temperature sensor broken
E21
d-21
Output over current
E22
d-22
DC offset over rating
E23
d-23
Fin high temperature
E26
d-26
DC/DC converter abnormal
E27
d-27
Relay open
E28
DC bus voltage abnormal
EEPROM
d-40
EEPROM abnormal
