Problem 1: Screen No displayed.
Fault Analysis: Without DC input,
1)PV lower voltage
2) PV terminal reversed
3) The DC switch turn off
4) PV in series disconnected.
5) PV short circuit
Solution: Multimeter test DC voltage input.
Problem 2: Inverter can not connected Grid.
1) The AC switch is off
2) The inverter AC output disconnected.
Solution: Multimeter test AC voltage output. the output should have 220V or 380V voltage.
3, PV Overvoltage
Fault analysis: DC overvoltage alarm
Reasons: Connect in series too more,Overvoltage
Solution: The temperature lower, the voltage higher . The input voltage range of single-phase 100-500V. The recommended voltage between 350-400V. The input voltage range of three-phase string inverter is 250-800V. The recommended voltage is 600- 650V.
4, the system output power too small:
Reasons: There are many factors affecting the output power, including solar radiation, the angle of the solar pv, dust and shadow, temperature.
Improper installation of the system configuration, solutions are as follow:
1) Check the power of PV is sufficient before installation.
2) Adjust the mounting angle and orientation
3) Check the shadows and dust.
4) Check the voltage range connected in series. If the voltage too low, system efficiency will decrease.
6) The inverter has dual MPPT . Each input power is only 50% of the total power. the power of each design should be equal. If only one MPPT connect, the output power will be halved.