Troubleshooting and Maintenance Guide for Solar Inverters

With the widespread adoption of photovoltaic (PV) power plants, the performance and reliability of solar inverters are critical to the overall efficiency and profitability of the system. Understanding how to handle common inverter issues and performing routine maintenance is essential for ensuring stable operations. This guide covers typical faults, their causes, solutions, and best practices for regular maintenance.

Common Solar Inverter Faults and Solutions

1. DC Overvoltage or Undervoltage

• Symptoms: The inverter displays a DC voltage error.
• Causes: Damaged components, faulty DC breakers, or abnormal panel output.
• Solutions: Replace damaged capacitors or inductors, repair or replace the DC breaker, and inspect panel connections to ensure proper output.

2. AC Side Faults

• Symptoms: Grid voltage errors, AC side short circuit, phase loss, or blown fuses.
• Causes: Grid voltage fluctuations, short circuits, or internal inverter damage.
• Solutions: Verify grid voltage is within the inverter's limits, isolate fault points, and repair or replace damaged components.

3. Low Insulation Resistance

• Symptoms: The inverter reports insulation resistance below the set threshold.
• Causes: Water intrusion in DC connectors, burned panel hotspots, or aging insulation materials.
• Solutions: Inspect and replace damaged connectors, replace leaking panels, and update aging insulation materials.

4. Low Bus Voltage

• Symptoms: The inverter displays low bus voltage.
• Causes: Insufficient panel generation or voltage regulator failure.
• Solutions: Ensure panels receive adequate sunlight without obstructions and repair or replace the voltage regulator.

5. Leakage Current Issues

• Symptoms: The inverter reports excessive leakage current.
• Causes: Poor-quality DC connectors or leakage in panels or grid equipment.
• Solutions: Replace low-quality connectors and repair or replace faulty panels or grid components.

6. DC Overvoltage Protection

• Symptoms: The inverter activates DC overvoltage protection.
• Causes: Excess panel output or misconfigured inverter settings.
• Solutions: Adjust panel output to within acceptable limits and reconfigure the inverter's overvoltage settings.

7. No Response on Startup

• Symptoms: The inverter fails to start.
• Causes: Incorrect DC wiring, power supply failure, or faulty control boards.
• Solutions: Ensure proper DC wiring polarity, repair or replace the power supply, and inspect and fix control boards.

  Routine Maintenance for Solar Inverters

  1. Diagnose Fault Codes

• Task: Regularly check the inverter's fault codes, record issues, and resolve them promptly.
• Frequency: During every routine power-off maintenance.

• 2. Inspect Power Supply

• Task: Verify the inverter’s power supply lines are intact and free from disconnections or shorts.
• Frequency: During each scheduled power-off maintenance.

• 3. Component Inspection

• Task: Check capacitors, diodes, thyristors, transistors, and other internal components for damage.
• Frequency: At least once a year.

• 4. Connection Check

• Task: Ensure all internal connections are secure and free of looseness.
• Frequency: Every power-off maintenance session.

• 5. Clean the Inverter

• Task: Use a blower or compressed air to remove dust and debris from the inverter.
• Frequency: Quarterly or semi-annually, depending on the operating environment.

• 6. Inspect Cooling Systems

• Task: Ensure cooling fans and airways are functioning correctly and unobstructed.
• Frequency: During routine power-off maintenance.

• 7. Check Surge Protectors

• Task: Verify the functionality of surge protectors to ensure proper operation.
• Frequency: At least once a year.

• 8. Examine Cables and Seals

• Task: Inspect for overheating or aging cables and ensure cable seals are intact.
• Frequency: At least annually.

  Maintenance Tips

• Always disconnect power before maintenance to ensure safety.
• Use appropriate tools and adhere to operational guidelines.
• Avoid opening the inverter in rain or snow to prevent water damage.

Yunfan Factory: Your Trusted Solar Energy Partner

At Yunfan Factory, we understand the importance of maintaining high inverter performance for your PV systems. Our solar inverters are designed for durability and ease of maintenance. We also offer customized battery solutions for various applications, ensuring optimal performance and adaptability.

With Yunfan’s advanced products and dedicated support, you can maximize system efficiency and minimize downtime.

Choose Yunfan for reliable, innovative energy solutions.