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Sungrow Error Codes

Expert reference guide covering all Sungrow inverter diagnostic codes with comprehensive troubleshooting procedures and professional repair guidance

Quickly identify problems with your Sungrow solar system and learn the correct response procedures

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Sungrow Inverter Models

Sungrow produces an extensive lineup of premium inverter systems for residential and commercial solar installations. The SG series represents single-phase and three-phase inverter technology with high efficiency, while SH series models provide hybrid solutions with battery integration. These diagnostic codes are applicable to the majority of Sungrow inverter systems sold in the United States. Error indicators typically manifest as status codes on the inverter display, LED status indicators, and status messages in the iSolarCloud monitoring portal.

How to Read Error Codes

• Check inverter display for error code numbers or messages
• Review LED status indicators on inverter
• Check iSolarCloud portal for system status messages
• Note error code format and any additional information
• Consult Sungrow documentation for your specific model

Sungrow Product Series

• SG Series - Single-phase and three-phase inverters
• SH Series - Hybrid inverters with battery integration
• ST Series - String inverters for commercial systems
• Data Logger - System monitoring and communication
• iSolarCloud - Cloud-based monitoring platform

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Understanding Diagnostic Codes

Sungrow inverter systems incorporate sophisticated diagnostic capabilities that automatically detect operational issues. When a problem is identified, the system communicates through error codes displayed on the inverter, LED status indicators, and status messages in the iSolarCloud monitoring portal. This intelligent diagnostic framework enables rapid problem identification and helps determine the appropriate response. All Sungrow inverter series (SG, SH, ST) utilize continuous performance monitoring with real-time error detection. Error codes may be displayed as numeric codes, text messages, or status indicators depending on the model. Always reference your specific model's installation manual for precise code definitions.

Grid Connection Errors

Problems with AC grid voltage, frequency, and connection.

Code	Meaning	Possible Causes	Solutions
Grid Overvoltage	Grid voltage exceeds maximum limit - System shutdown for safety	•Utility grid voltage too high •Grid voltage fluctuations •Transformer tap settings •Grid instability •Voltage regulation issue	Do not attempt to override safety shutdown Check utility grid voltage with multimeter Contact utility company to report voltage issues Wait for grid voltage to return to normal range System will automatically reconnect when voltage stabilizes Contact certified installer if voltage issues persist
Grid Undervoltage	Grid voltage below minimum limit - System shutdown for safety	•Utility grid voltage too low •Grid voltage fluctuations •Transformer issues •Grid instability •Voltage drop in distribution	Do not attempt to override safety shutdown Check utility grid voltage with multimeter Contact utility company to report voltage issues Wait for grid voltage to return to normal range System will automatically reconnect when voltage stabilizes Contact certified installer if voltage issues persist
Grid Frequency Out of Range	Grid frequency deviation from allowable range - System shutdown	•Grid frequency too high •Grid frequency too low •Grid instability •Frequency fluctuations •Grid synchronization issue	Check grid frequency (should be 50Hz or 60Hz depending on region) Verify frequency is within allowable limits Inverter will automatically attempt to reconnect when frequency returns to normal Wait for grid frequency to stabilize Contact utility company if frequency is consistently out of range Contact installer if problem persists
Grid Disconnected	System has lost connection to utility grid	•Grid power outage •Main breaker tripped •Utility disconnect •Grid failure •Anti-islanding protection	Verify grid power is actually lost Check main breaker for system This is normal safety behavior during grid outage Wait for grid power to be restored System will automatically reconnect when grid is restored If grid is normal, contact installer to check grid connection

DC Voltage and Isolation Errors

Problems with DC input voltage and electrical isolation.

Code	Meaning	Possible Causes	Solutions
DC Overvoltage	DC input voltage exceeds maximum limit	•Too many modules per string •String voltage exceeds maximum •Cold weather voltage rise •Incorrect string configuration •Module mismatch	Check string voltage with multimeter Verify number of modules per string matches inverter specifications Review string configuration in installation manual Account for cold weather voltage rise in calculations Verify module specifications match system design Contact certified installer to verify string configuration
DC Undervoltage	DC input voltage below minimum operating threshold	•Too few modules per string •Shading on panels •Faulty modules •DC wiring losses •String configuration error	Check string voltage with multimeter Verify minimum number of modules per string Inspect panels for shading Check for faulty modules in string Verify DC wiring connections Review string configuration Contact certified installer if voltage remains low
Isolation Fault	Isolation error detected between PV system and ground	•Damaged PV module insulation •Water ingress in junction boxes •Damaged DC wiring insulation •Ground fault in PV array •Faulty inverter isolation monitoring	Immediately shut down the system Do not attempt to restart until fault is resolved Inspect all PV module connections and junction boxes Check DC wiring for damage or water ingress Test isolation resistance with megohmmeter Contact certified Sungrow installer immediately This is a serious safety condition requiring professional diagnosis

Temperature and Overheating Errors

Problems with inverter temperature and thermal protection.

Code	Meaning	Possible Causes	Solutions
Overtemperature	Inverter temperature exceeds maximum limit	•Insufficient ventilation •Direct sunlight on inverter •High ambient temperature •Blocked air vents •Faulty cooling fan	Improve ventilation around inverter Ensure inverter is not in direct sunlight Check that air vents are not blocked Verify adequate clearance around inverter Check cooling fan operation Allow inverter to cool down before restart Contact installer if temperature remains high after improving ventilation
Temperature Sensor Error	Temperature sensor fault or communication error	•Faulty temperature sensor •Sensor wiring issue •Internal sensor failure •Communication error	Check temperature sensor connections Verify sensor is functioning Contact Sungrow support for sensor diagnostics May require inverter service

DC Current and Power Errors

Problems with DC current and power generation.

Code	Meaning	Possible Causes	Solutions
DC Overcurrent	DC input current exceeds maximum limit	•Too many modules per string •Short circuit in string •Faulty modules •DC wiring issue •Current exceeds maximum	Check DC current Verify string configuration Inspect for short circuits in string Check for faulty modules Verify DC wiring connections Contact certified installer for diagnosis Do not attempt to repair yourself
No DC Power	Inverter not receiving DC power from solar panels	•DC disconnect open •String breakers off •Faulty DC connections •No solar irradiance •Panel failure	Check DC disconnect switches Verify string breakers are ON Inspect DC connections Check for solar irradiance (daytime) Verify panels are generating DC voltage Check for panel or string failures Contact installer if DC power should be available
Low Power Generation	Energy production significantly below expected levels	•Shading on panels •Dirty or soiled panels •Panel degradation •Inverter derating •DC wiring losses •Mismatched panels	Clean solar panels to remove dirt, dust, or debris Check for shading throughout the day Inspect panels for physical damage or hot spots Verify all strings are operating Compare production to expected values for current conditions Check DC wiring for loose connections or damage Review panel specifications and inverter compatibility Contact certified installer for production analysis

Communication and Monitoring Errors

Problems with communication and monitoring systems.

Code	Meaning	Possible Causes	Solutions
No Communication with Data Logger	Inverter cannot communicate with Sungrow Data Logger	•Communication wire break •Data Logger offline •Network issue •Communication protocol error	Check communication wiring between inverter and Data Logger Verify Data Logger is powered and online Check network connection Restart Data Logger if needed Verify communication settings Contact installer if communication cannot be restored
iSolarCloud Not Accessible	iSolarCloud monitoring portal not accessible or showing errors	•Internet connection issue •Data Logger offline •Server connectivity problem •Account access issue	Check internet connection Verify Data Logger is online Check iSolarCloud server status Verify account credentials Restart Data Logger if needed Contact Sungrow support if portal remains inaccessible
Modbus Communication Error	Modbus communication failure with external devices	•Modbus wiring issue •Device not responding •Communication protocol error •Address conflict	Check Modbus wiring connections Verify device addresses are correct Test Modbus communication Check for address conflicts Review Modbus configuration Contact installer for Modbus troubleshooting

Arc Fault and Safety Errors

Critical safety errors related to arc detection.

Code	Meaning	Possible Causes	Solutions
Arc Fault Detected	Arc fault detected in system - potential fire hazard	•Loose DC connections •Damaged DC wiring •Corroded connections •Faulty connectors •Arc in PV array	Immediately shut down the system Do not attempt to restart Contact certified installer immediately This is a critical safety condition Inspect all DC connections for looseness Check DC wiring for damage Professional inspection required before restart
Ground Fault Detected	Ground fault protection activated - System shutdown for safety	•DC ground fault •AC ground fault •Wiring issue •Equipment failure	Do not attempt to restart system This is a serious safety condition Immediately contact certified installer Do not touch any system components Professional diagnosis required System must be inspected before restart

Internal Inverter Errors

Problems with inverter internal systems and hardware.

Code	Meaning	Possible Causes	Solutions
Internal Inverter Error	Internal inverter fault or hardware error	•Internal inverter fault •Control board issue •Hardware failure •Component malfunction	Attempt inverter restart If error persists, contact Sungrow support Do not repeatedly restart if error continues Note error code and contact certified installer May require inverter replacement or repair
Power Stage Error	Inverter power stage fault	•Power stage failure •IGBT failure •DC/AC conversion issue •Hardware malfunction	Contact Sungrow support immediately This requires professional diagnosis Inverter may need repair or replacement Do not attempt to repair yourself
Control Board Error	Inverter control board fault	•Control board failure •Firmware error •Memory error •Internal communication error	Contact Sungrow support May require firmware update Professional service may be needed Do not attempt to repair yourself

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Critical Safety Notice

Do not attempt DIY repairs on your Sungrow solar system. The majority of diagnostic codes relate to high-voltage DC and AC electrical systems, grid connection safety mechanisms, or critical safety features. Specific codes requiring immediate professional intervention include: Isolation Fault, Arc Fault Detected, and Ground Fault Detected. Upon encountering these codes, immediately shut down the system if safe to do so and contact a certified Sungrow installer without delay.

Professional service is mandatory—contact a licensed solar installer or reach out to Sungrow technical support for expert assistance.

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Maintenance Guidelines

Scheduled Service Requirements

✓Professional inspection and service annually by certified Sungrow installer
✓Monthly visual inspection of solar panels for damage or soiling
✓Clean panels quarterly or as needed based on local conditions
✓Monitor system performance daily through iSolarCloud portal
✓Check inverter status and LED indicators monthly
✓Verify Data Logger is online and communicating

Proactive Maintenance Strategies

✓Keep panels clean to maximize energy production
✓Trim trees and vegetation to prevent shading
✓Ensure adequate ventilation around inverter
✓Monitor production trends for early problem detection
✓Keep firmware updated for latest features and fixes
✓Review system alerts and error codes promptly

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Frequently Asked Questions

What should I do if I see "Grid Overvoltage" error?

Grid Overvoltage indicates that the grid voltage exceeds the maximum limit. Do not attempt to override the safety shutdown. Check utility grid voltage with a multimeter and contact the utility company to report voltage issues. Wait for grid voltage to return to normal range. The system will automatically reconnect when voltage stabilizes. Contact a certified installer if voltage issues persist.

What does "Isolation Fault" mean?

Isolation Fault indicates an isolation error detected between the PV system and ground. Immediately shut down the system and do not attempt to restart until the fault is resolved. Inspect all PV module connections and junction boxes, check DC wiring for damage or water ingress, and test isolation resistance. This is a serious safety condition requiring professional diagnosis. Contact a certified Sungrow installer immediately.

What should I do if my inverter shows "Overtemperature"?

Overtemperature indicates that the inverter temperature exceeds the maximum limit. Improve ventilation around the inverter, ensure it is not in direct sunlight, check that air vents are not blocked, verify adequate clearance around the inverter, and check cooling fan operation. Allow the inverter to cool down before restart. Contact an installer if temperature remains high after improving ventilation.

What does "Arc Fault Detected" mean?

Arc Fault Detected indicates that an arc fault has been detected in the system, which is a potential fire hazard. Immediately shut down the system and do not attempt to restart. Contact a certified installer immediately. This is a critical safety condition. Inspect all DC connections for looseness and check DC wiring for damage. Professional inspection is required before restart.

Can I repair my Sungrow system myself?

High-voltage DC and AC electrical work must exclusively be performed by licensed professionals to ensure safety compliance. Homeowners can safely perform basic tasks like cleaning panels and monitoring the iSolarCloud portal, but all technical repairs require certified Sungrow installers. Unauthorized work on electrical systems poses extreme danger and violates building codes.

How do I check if my Data Logger is working?

Check Data Logger status in the iSolarCloud portal. Verify the Data Logger is powered and online, check the network connection, and verify communication settings. If the Data Logger is offline, check communication wiring between the inverter and Data Logger, restart the Data Logger if needed, and contact an installer if communication cannot be restored.

What should I do if I see "Low Power Generation"?

Low Power Generation indicates that energy production is significantly below expected levels. Clean solar panels to remove dirt, dust, or debris, check for shading throughout the day, inspect panels for physical damage or hot spots, verify all strings are operating, compare production to expected values for current conditions, check DC wiring for loose connections or damage, and review panel specifications and inverter compatibility. Contact a certified installer for production analysis.

How often should I clean my solar panels?

Solar panels should be cleaned quarterly or as needed based on local conditions. Panels in dusty areas or areas with heavy pollen may need more frequent cleaning. Keep panels clean to maximize energy production. Inspect panels monthly for damage or excessive soiling that may require immediate cleaning.

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Summary

Proper interpretation of diagnostic codes is essential for effective Sungrow solar system troubleshooting. This comprehensive reference enables quick problem identification and guides appropriate response actions. Sungrow systems utilize error codes displayed on inverter displays, LED status indicators, and status messages in the iSolarCloud monitoring portal to indicate specific sensor and system malfunctions. SG, SH, and ST series inverters provide diagnostic information through error codes and monitoring systems for convenient diagnosis.

⚠️Complex diagnostic situations, especially those involving high-voltage DC and AC electrical systems and grid connection safety, require immediate professional evaluation. Critical codes demanding urgent response include: Isolation Fault, Arc Fault Detected, and Ground Fault Detected. These indicators represent serious safety hazards requiring certified Sungrow installer response. Adherence to scheduled maintenance protocols and immediate attention to diagnostic codes extends equipment service life and minimizes long-term operational costs. Note that error code formats may vary by model and firmware version—always consult your specific unit's installation and service manual for precise interpretations.