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user should stop the device and check the specific insulation resistance via the LCD
screen “Function/Run-information/Real time data”.
•
If the insulation resistance recovers to be normal, the fault loop is on the AC side.
•
If the insulation resistance is still low, the fault loop is on the DC side.
•
Whether the fault is on the DC side or AC side, switch off the system and perform a
thorough checking and troubleshooting.
11.10 Protection Function
The inverter has complete protection functions to protect itself when input voltage or
grid is abnormal. After the anomaly is removed, the inverter can operate normally.
11.10.1 DC Over-voltage Protection
When the DC voltage of the PV array exceeds the max. DC voltage, the inverter will stop
operating, send warning signal, and display the fault type on the LCD screen.
The inverter can detect the abnormal voltage and respond quickly.
11.10.2 AC Over/under-voltage Protection
When the inverter AC output voltage exceeds the permissible range, the inverter will
stop feeding the grid, send warning signal, and display the fault type on the LCD screen.
The inverter can detect the abnormal voltage and respond quickly.
11.10.3 Frequency Anomaly Protection
When the grid frequency exceeds the permissible range, the inverter will stop feeding
the grid, send warning signal, and display the fault type on the LCD screen.
The inverter can detect the abnormal frequency and respond quickly.
11.10.4 Islanding Protection
Islanding is a case that can occur if the utility grid is disconnected while the inverter is
operating and the local load of the inverter is similar to the present output power.
“Islanding” is a potential threaten to devices and operators.
•
In the event of grid outage, if the inverter still feeds power to the public grid, death or
injury may occur to the maintainers during maintenance.
•
In the event of grid fault, if the inverter still feeds power to the public grid, a surge
current may occur and damage devices once the grid resumes.
The inverter is equipped with anti-islanding protection function.
In anti-islanding protection state, high voltage is still present. Disconnect the
main switch and wait the device to discharge completely before testing or
maintenance.
System Manual
Summary of Contents for SG3125HV-20
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