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A flashing fault code on your Sungrow inverter can halt your solar system—but with the right guide, you’ll be back online in minutes. Sungrow inverters are highly reliable, but like any technology, they require maintenance and occasional troubleshooting. This guide is designed to help homeowners, electricians and solar installers diagnose and resolve errors quickly and effectively.
Whether you’re dealing with a simple connection issue or a more complex hardware fault, understanding Sungrow’s fault codes can save time, protect warranties, and minimise downtime. Keep reading to learn why these codes appear and how to troubleshoot them efficiently.
Initial Troubleshooting Checklist
When a fault code appears, follow these initial steps to assess the situation:
1. Safety First
Always prioritise safety. Turn off the inverter using the DC and AC switches, and wait at least five minutes before inspecting the unit to avoid electrical hazards.
2. Perform Basic Checks
Connections:
Ensure that all grid and PV connections are securely in place. Loose or corroded connections can trigger fault codes.
Wifi Connection:
If you run into the issue of the inverter not having a wifi connection, follow the steps in this video:
Error code 010:
Error code 010 indicates a loss of connection to the electrical grid. This can occur due to a local power outage or a tripped circuit breaker in your switchboard. If there’s a power outage, the inverter will automatically reconnect once power is restored. If there’s no outage, inspect your switchboard for a tripped circuit labeled “Main Switch Inverter Supply.” To reset it, flip the switch to the “off” position and then back to “on.”
iSolarCloud app:
Regarding iSolarCloud app login issues, ensure that the server region is set to “AU – Australia” in the app settings. If you’re still unable to log in, try resetting your password. If problems continue, consider reaching out to Sungrow’s service department for support.
Physical Condition
Inspect the inverter for visible damage, debris, or blockages in ventilation that could cause overheating.
Soft Reset
Turn off the inverter completely, wait two minutes, and restart it. A soft reset can often resolve minor issues.
3. Pro Tip: Document Error Patterns
Take note of when the fault occurs, such as specific times of day or weather conditions. This information can help in diagnosing recurring issues and identifying patterns that may point to root causes.
Sungrow Inverter Fault Codes: Reference Table
| Code | Description | Solutions | Category |
|---|---|---|---|
| 002 | Grid Overvoltage | Check grid voltage; contact utility provider if unstable | Grid-Related |
| 010 | Islanding (grid disconnection) | Verify AC circuit breaker and cables; ensure grid is operational | Grid-Related |
| 014 | 10-Minute Grid Overvoltage | Confirm correct country code setting; monitor grid stability | Grid-Related |
| 021 | PV1 Input Overcurrent | Inspect PV1 wiring/panel layout; reduce string size if necessary | PV System |
| 036 | Radiator Overheating | Clean vents, check fans, ensure proper ventilation | Temperature |
| 037 | Internal Overheating | Relocate inverter to shaded area; replace faulty fans | Temperature |
| 038 | Relay Fault (grid side) | Test phase-to-ground voltage; replace inverter if voltage is normal | Hardware |
| 039 | Low Insulation Resistance (ISO-flt) | Test PV strings for ground faults using a multimeter | PV System |
| 070 | Fan Defect | Clean/replace fans; ensure unobstructed airflow | Hardware |
| 085 | Software Version Mismatch | Update firmware via Sungrow support | Software |
| 100 | AC Output Overcurrent | Reduce connected loads; check for short circuits | Overcurrent |
| 203 | PV Input Voltage Exceeds Bus Voltage | Verify PV string configuration matches inverter specs | PV System |
In-Depth Solutions for Critical Fault Codes
Even with proper maintenance, Sungrow inverters may occasionally display critical fault codes. Here are step-by-step solutions to resolve some of the most common and significant errors:
Code 039: Low Insulation Resistance
This fault indicates a potential safety issue related to insulation.
- Step 1: Disconnect all PV strings from the inverter to isolate the issue.
- Step 2: Use a megohmmeter to test the insulation resistance. The value should be greater than 1 MΩ to ensure proper insulation.
- Step 3: Inspect rooftop isolators for signs of moisture damage or wear. If damaged, replace them immediately to restore safe operation.
Code 037: Internal Overheating
Internal overheating is typically caused by environmental conditions or cooling system issues.
- Step 1: Check the location of the inverter and, if necessary, relocate it to a shaded, well-ventilated area to reduce heat exposure.
- Step 2: Inspect the inverter’s cooling fans. If you notice abnormal noise or blockages, clean or replace the fans to ensure proper airflow.
Prevention Tips to Avoid Common Errors
Preventative maintenance and mindful installation practices can significantly reduce the occurrence of Sungrow inverter errors.
Regular Maintenance
- Clean air filters to maintain proper airflow and prevent overheating.
- Update the inverter firmware to stay aligned with the latest performance improvements and error fixes.
- Inspect wiring for signs of wear or loose connections.
Environmental Best Practices
- Install inverters in shaded, well-ventilated areas to minimise overheating risks.
- Avoid installing inverters in locations prone to moisture or extreme weather conditions.
Professional Monitoring
- Schedule bi-annual inspections with a licensed electrician to ensure your system complies with grid standards and operates at peak efficiency.
When to Call a Professional Electrician
While many Sungrow inverter issues can be resolved with basic troubleshooting, some situations require the expertise of a certified professional.
Complex Hardware Failures
Codes such as 038 (relay failure) or 040 (hardware overvoltage) indicate internal hardware issues that often require replacement parts or advanced diagnostics.
Persistent Grid Errors
If codes like 002 (grid undervoltage) or 014 (grid overfrequency) occur repeatedly, it could point to deeper instability in the grid. A professional electrician can assess and rectify these issues.
Safety Risks
Errors such as 039 (low insulation resistance) or 011 (DC injection overcurrent) involve potential safety hazards. Professional intervention is essential to resolve these issues safely and effectively.
Need Professional Help?
If your Sungrow inverter is displaying fault codes that you can’t resolve, don’t wait—safety and efficiency are too important to risk. Tenmen Electrical offers certified Sungrow inverter repairs and troubleshooting in the Sunshine Coast area. Contact us to get your system back online and running smoothly!
