1. Low insulation impedance: Use exclusion method. Unplug all the strings on the input side of the inverter, and then connect them one by one. Use the function of detecting insulation impedance when the inverter is turned on to detect problem strings. After finding the problem string, focus on checking whether there are water immersed or melted short-circuit brackets in the DC connector. In addition, you can also check whether there are black spots on the edges of the components that have been burned, causing them to leak electricity to the grounding grid through the frame.

2. Low bus voltage: If it occurs during early/late hours, it is a normal problem because the inverter is trying to generate maximum power conditions. If it occurs during normal daytime, the detection method is still the exclusion method, and the detection method is the same as item 1.

3. Leakage current fault: The root cause of such problems is installation quality issues, caused by choosing the wrong installation location and low-quality equipment. There are many fault points: low-quality DC connectors, low-quality components, inadequate installation height of components, low quality of grid connected equipment or water leakage. Once similar problems occur, they can be solved by sprinkling powder to identify the * * point and doing insulation work. If it is a material saving problem, the only solution is to replace the material.

4. DC overvoltage protection: With the pursuit of high-efficiency process improvement in components, power levels are constantly updated and rising. At the same time, the open circuit voltage and operating voltage of components are also increasing. In the design phase, temperature coefficient issues must be considered to avoid overvoltage caused by low temperature conditions leading to equipment damage.

5. Inverter startup unresponsive: Please ensure that the DC input line is not reversed. Generally, DC connectors have anti misoperation effects, but the crimping terminals do not have anti misoperation effects. It is important to carefully read the inverter manual to ensure that the positive and negative poles are connected before crimping. The inverter is equipped with reverse short-circuit protection and can start normally after restoring normal wiring.

6. Power grid faults: Possible faults such as overvoltage, undervoltage, over/under frequency, no voltage, and phase loss may occur in the power grid. Check the grid connected lines and phase loss circuits