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Photovoltaic Inverter Repair & Diagnostics

  • In-depth diagnostics of inverter failures — including internal explosions, burnt PCBs, and severe hardware faults
  • Root-cause analysis using oscilloscopes, logic analyzers, and load simulations
  • Detection and elimination of software-related faults: EEPROM corruption, firmware bugs, and error code resolution
  • Repair of MPPT modules, power stages, gate drivers, and signal path anomalies
  • Troubleshooting of grid synchronization, DC link stability, and AC waveform distortion
  • Detailed failure reports, waveform captures, and high-resolution photos of defective areas

Inverter Component Restoration & Upgrades

  • Replacement of IGBTs, MOSFETs, optocouplers, control ICs, and passive components
  • Micro-soldering and trace repair for severely damaged circuit boards
  • Custom replacement of rare or obsolete components using 3D-printed or CNC-machined parts
  • Rebuilding of cooling systems: fan units, thermal paste, and heat sink realignment
  • Reinforcement against future failures: conformal coating, transient suppression modules, and enhanced insulation paths
  • Optional firmware optimization for extended inverter lifespan and better grid behavior
  • Includes post-repair testing, load simulation, and full technical documentation with results

Advanced Inverter Diagnostics

  • Complete diagnostics using professional Fluke and Tektronix equipment
  • Electrical parameter analysis with 0.1% precision accuracy
  • Thermal imaging diagnostics to detect hidden defects
  • Insulation and grounding testing according to VDE standards
  • Detailed report with photographic documentation of all problem areas

Control Board Reprogramming

  • Factory firmware restoration for all inverter brands
  • EEPROM and Flash memory programming
  • Software adaptation for specific operating conditions
  • Firmware updates to latest versions
  • Original settings backup and recovery

PCB Board Restoration

  • Circuit trace restoration using micro-soldering techniques
  • BGA component replacement on professional rework stations
  • CPU and microchip reballing services
  • Contact pad restoration and repair
  • Protective coating application against corrosion

Final Quality Testing

  • Complete safety function verification
  • Overload condition testing
  • Calibration of all measurement circuits
  • Quality certificate with comprehensive test protocols

List of errors on the inverter Sunways


By Erik Zaikin
3 min read


Troubleshooting Guide for Solar Inverter Faults

Fault 101: U-CCmax (DC Voltage Too High)

  • Description: The Solar Inverter is certified for a maximum open-circuit voltage of 680V. Components are designed with a sufficient safety factor. If exceeded, it stops feeding into the grid.
  • Remedy:
    • Check the sizing of your PV generator. Too many modules may be connected in series.
    • Reduce the number of modules and re-commission the system.

Fault 102: Isolation (Isolation Fault)

  • Description: Before each start-up, the Solar Inverter checks for ground leaks or insulation errors. If detected, feeding into the grid is stopped.
  • Remedy:
    • Check the PV system for possible insulation faults (e.g., crushed DC cables).

Fault 103: AFI>30mA (Differential Current Jump)

  • Description: Equipped with an AFI device sensitive to all currents, a differential current jump of >30 mA has been detected.
  • Remedy:
    • Inspect the PV system for potential insulation errors.

Fault 104: AFI>0.3A (Absolute Differential Current Jump)

  • Description: A differential current jump greater than 300mA was detected during operation.
  • Remedy:
    • Check the PV installation for possible insulation issues.

Fault 201: Overvoltage Error

  • Description: Constantly monitors AC network quality. High voltage peaks during grid feed-in will cause the inverter to stop and attempt to restart.
  • Remedy:
    • The inverter will restart automatically after the fault is cleared. If the error occurs often, consult your electricity provider.

Fault 203: UCA1>15% (AC Voltage Too High)

  • Description: Monitors the voltage level of the feeding phase. If it exceeds the maximum allowable value, it stops feeding into the grid.
  • Remedy:
    • Verify the configuration of the grid connection (energy meter) and discuss with your electricity provider about network stability.

Fault 204: UCA1<min (AC Voltage Too Low)

  • Description: If the minimum allowable voltage is exceeded, the inverter stops feeding into the grid.
  • Remedy:
    • Consult with your electricity provider about network stability and configuration.

Fault 210: Frq1>max (Frequency Too High)

  • Description: Constantly monitors the grid frequency. If it exceeds the allowable value, the inverter stops feeding into the grid.
  • Remedy:
    • Consult with your electricity provider for details on network stability.

Fault 211: Frq1<min (Frequency Too Low)

  • Description: Similar to fault 210 but for low frequency.
  • Remedy:
    • Same as for Frq1>max, consult your electricity provider.

Fault 212: DC Quota (Increased DC Content)

  • Description: Monitors the quality of accumulated current. If increased DC content is detected, the inverter stops feeding into the grid.
  • Remedy:
    • Restart the Solar Inverter. If the error repeats, contact technical support.

Fault 301: AFI-Over (Fault Current Measurement Range Exceeded)

  • Description: The integrated fault current sensor was used outside its measurement range.
  • Remedy:
    • Restart the Solar Inverter. Contact technical support if the error persists.

Fault 302: Monitoring Error

  • Description: The redundant monitoring unit detects deviations or errors in the regulation's measured values.
  • Remedy:
    • Restart the Solar Inverter. Contact technical support if the error repeats.

Fault 303: Overtemperature (Warning)

  • Description: Designed for ambient temperatures up to +40°C. Feeding power is linearly reduced upon reaching a pre-set temperature threshold of the heat sink.
  • Remedy:
    • Find a more suitable installation location. Clean the Solar Inverter if dirt hampers cooling.

Faults 401-422: Various Communication and Configuration Errors

  • Description: Errors related to SD card detection, CAN communication failures, SMTP server connection issues, DNS failures, and HTTP protocol errors.
  • Remedy:
    • Restart the Solar Inverter for immediate issues. Verify network settings, ensure proper cable connections, and consult technical support for persistent problems.

9xx: Maintenance Error

  • Description: An error related to maintenance has occurred.
  • Remedy:
    • Disconnect and reconnect the Solar Inverter from the grid and solar generator. If the error repeats, contact technical support.

AT2700 AT3000 AT 3600 AT4500 AT5000
NT2500 NT3700 NT4200 NT5000
NT10000 NT11000 NT12000
PT30K PT33K

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