Fronius Symo Fault Codes

Fronius Symo Fault Codes

The Fronius Symo is a popular choice among Australian homeowners and businesses for its reliability and efficiency. However, there might be times when your inverter communicates a hiccup via a fault code. These codes can be found on the inverter’s display or its online interface. They serve as a guidepost, helping you identify and resolve issues.

This article dives deep into the fault codes for the Fronius Symo, offering a clear understanding by listing the code number, explaining what it indicates, detailing the behaviour associated with the fault, and suggesting remedies.

Fronius Symo fault codes beginning with 1xx

Code
Description
Behaviour
Remedy
STATE 102 AC voltage too high Following careful testing and when the grid conditions are within the permissible range again, the inverter will resume feeding energy into the grid. Check grid connections: If this STATE code keeps recurring contact your solar power system installer.
STATE 103 AC voltage too low
STATE 105 AC frequency too high
STATE 106 AC frequency too low
STATE 107 AC grid outside the permissible limits
STATE 108 Stand alone operation detected
STATE 112 RCMU error

Fronius Symo fault codes beginning with 3xx

Code
Description
Behaviour
Remedy
STATE 301 Overcurrent (AC) Short-term interruption while feeding energy into the grid due to over current in the inverter.
The inverter resumes with its startup routine.
Fault is rectified automatically; if this STATE code is displayed all the time: notify your local Fronius service partner.
STATE 302 Overcurrent (DC)
STATE 303 DC module over temperature Short term interruption while feeding energy into the grid due to over temperature.
The inverter resumes with its startup routine.
Purge openings for cooling air and heat sink if necessary; fault is rectified automatically; if this STATE code keeps recurring contact your solar power system installer.
STATE 304 AC module over temperature
STATE 305 No power being fed in, despite closed relay Short term interruption while feeding energy into the grid due to over temperature.
The inverter resumes with its startup routine.
fault is rectified automatically; if this STATE code keeps recurring contact your solar power system installer.
STATE 306 PV output too low for feeding energy into the grid Short term interruption while feeding energy into the grid.
The inverter resumes with its startup routine.
Fault is rectified automatically; if this STATE code occurs when there is sufficient insolation (sunlight) contact your solar power system installer.
IMPORTANT! Due to the low level of insolation (sunlight) early in the morning and in the evening, the STATE codes 306 (LOW PV OUTPUT) and 307 LOW PV VOLTAGE) are displayed routinely at these times of day. These STATE codes do notindicate any kind of fault.
STATE 307 LOW PV VOLTAGE
DC input voltage too low for feeding energy into the grid
STATE 308 Intermediate circuit voltage too high Short term interruption while feeding energy into the grid. The inverter resumes with its startup routine. Fault is rectified automatically; if this STATE code is displayed all the time: notify your local Fronius service partner.
STATE 309 DC input voltage MPPT 1 too high
STATE 311 Polarity of DC strings reversed
STATE 313 DC input voltage MPPT 2 too high
STATE 314 Current sensor calibration timeout Short term interruption while feeding energy into the grid. The inverter resumes with its startup routine. Fault is rectified automatically; if this STATE code is displayed all the time: notify your local Fronius service partner.
STATE 315 AC current sensor erro
STATE 316 Interrupt Check fail
STATE 325 Overtemperature in the connection area
STATE 326 Fan 1 error
STATE 327 Fan 2 error

Fronius Symo fault codes beginning with 4xx

Code
Description
Behaviour
Remedy
STATE 401 No communication possible with the power stage set The inverter will automatically attempt to connect again and, if possible, will resume feeding energy into the grid. If the STATE code is displayed all the time contact your local Fronius Service Partner
STATE 406 AC module temperature sensor faulty (L1)
STATE 407 AC module temperature sensor faulty (L2)
STATE 408 DC component measured in the grid too high
STATE 412 Fixed voltage mode has been selected instead of MPP voltage mode and the fixed voltage has been set to too low or too high a value If this STATE code persists contact your solar power system installer
STATE 415 Safety cut out via option card or RECERBO has triggered The inverter is not feeding any energy into the grid. If the STATE code is displayed all the time contact your local Fronius Service Partner
STATE 416 No communication possible between power stage set and control system The inverter will automatically attempt to reconnect again and, if possible, will resume feeding energy into the grid.
STATE 417 Hardware ID problem Update the inverter firmwarewith the latest firmware here; if the STATE code is displayed all the time after the firmware update contact your local Fronius Service Partner.
STATE 419 Unique ID conflict
STATE 420 No communication possible with the Hybrid manager
STATE 421 HID range error
STATE 425 No communication with the power stage set possible
STATE 426-428 Possible hardware fault
STATE 431 Software problem The inverter is not feeding any energy into the grid. Carry out an AC reset (switch the AC circuit breaker off and on); update inverter firmware; if this status code is displayed all the time please contact your local Fronius Service Partner.
STATE 436 Functional incompatibility (one or more PC boards in the inverter are not compatible with each other, e.g. after a PC board has been replaced. The inverter will automatically attempt to connect again and, if possible, will resume feeding energy into the grid. Update the inverter firmwarewith the latest firmware here; if the STATE code is displayed all the time after the firmware update contact your local Fronius Service Partner.
STATE 437 Power stage set problem
STATE 438 Functional incompatibility (one or more PC boards in the inverter in the inverter are not compatible with each other, e.g. after a PC board has been replaced)
STATE 443 Intermediate circuit voltage too low or asymmetric The inverter is not feeding any energy into the grid. If the status code is displayed all the time contact your local Fronius Service Partners.
STATE 445 – Compatability error (e.g. due to replacement of a PC board)
– invalid power stage set configuration
The inverter is not feeding any energy into the grid for safety reasons. Update the inverter firmwarewith the latest firmware here; if the STATE code is displayed all the time after the firmware update contact your local Fronius Service Partner.
STATE 447 Insulation fault If this status code is displayed all the time: notify a local Fronius Service Partner
STATE 448 Neutral conductor not connected
STATE 450 Guard cannot be found
STATE 451 Memory error detected The inverter will automatically attempt to connect again, and if possible, will resume feeding energy into the grid. If the STATE code is displayed all the time: notify your local Fronius Service Partner.
STATE 452 Communication error between the processors
STATE 453 Grid voltage and power stage set are incompatible
STATE 454 Grid frequency and power stage set are incompatible
STATE 456 Anti-islanding function is no longer implemented correctly
STATE 457 Grid relay sticking or the neutral conductor ground voltage is too high The inverter is not feeding any energy into the grid. Check the grounding (the neutral conductor ground voltage must be less than 30V. If problem persists contact your local Fronius Service Partner.
STATE 458 Error when recording the measuring signal Contact your local Fronius Service Partner.
STATE 459 Error when recording the measuring signal for the insulation test
STATE 460 Reference voltage source for the digital signal processor (DSP) is working out of tolerance
STATE 461 Fault in the DSP data memory
STATE 462 Error with DC feed monitoring routine
STATE 463 Reversed AC polarity, AC connector inserted incorrectly
STATE 474 RCMU sensor faulty
STATE 475 Solar panel ground fault, insulation fault (connection between solar panel and ground)
STATE 476 Driver supply voltage too low
STATE 480, 481 Functional incompatibility (one or more PC boards in the inverter are not compatible with each other, e.g. after a PC board has been replaced) Update the inverter firmwarewith the latest firmware here; if the STATE code is displayed all the time after the firmware update contact your local Fronius Service Partner.
STATE 482 Setup after the initial start-up was interrupted Perform AC reset (turn AC circuit breaker off and on), complete startup.
STATE 483 Voltage UDC fixed on MPP2 string out of limits Check the MPP settings; if the status code is displayed all the time contact your local Fronius Service Partner
STATE 485 CAN transmit buffer is full Carry out an AC reset (turn AC circuit breaker off and on), if the STATE code continues to be displayed notify your local Fronius Service Partner.

Fronius Symo fault codes beginning with 5xx

Code
Description
Behaviour
Remedy
STATE 502 Insulation error on the solar panels Warning message is shown on the display If this STATE code keeps recurring, contact your solar power system installer.
STATE 509 No energy fed into the grid in the past 24 hours Acknowledge STATE code; check whether all the conditions for the problem free feeding of energy into the grid have been met. If the STATE code is displayed all the time: look out for further STATE codes.
STATE 515 No communication with filter possible If the status code is displayed all the time notify your local Fronius Service Partner.
STATE 516 No communication possible with the storage unit Storage unit warning message.
STATE 517 Power derating caused by too high a temperature When power derating occurs, a warning message is shown on the display Purge cooling air openings and heat sink if necessary; fault is rectified automatically; if this STATE code keeps recurring contact your solar power system installer.
STATE 518 Internal DSP malfunction Warning message on the display If this STATE code keeps recurring contact your solar power system installer.
STATE 519 No communication possible with the storage unit Storage unit warning message
STATE 520 No energy fed into the grid by MPPT1 in the past 24 hours Warning message is shown on the display Acknowledge status code; check whether all the conditions for the problem free feeding of energy into the grid has been met. If this STATE code keeps recurring contact your solar power system installer.
STATE 522 DC low string 1 Warning message on the display
STATE 523 DC low string 2
STATE 558, 559 Functional incompatibility (one or more PC boards in the inverter are not compatible with each other, e.g. after a PC board has been replaced) Update the inverter firmwarewith the latest firmware here; if the STATE code is displayed all the time after the firmware update contact your local Fronius Service Partner.
STATE 560 Derating caused by over-frequency This STATE code is displayed when the grid frequency becomes excessively high. The inverter will then reduce its output. The status indicator will continue to be displayed until the inverter has returned to normal operation. As soon as the grid frequency is back within the permissible range and the inverter has returned to normal operation, the fault is rectified automatically. If this STATE code keep recurring contact your solar power system installer.
STATE 564 Functional incompatibility (one or more PC boards in the inverter are not compatible with each other, e.g. after a PC board has been replaced) Warning message on the display Update the inverter firmwarewith the latest firmware here; if the STATE code is displayed all the time after the firmware update contact your local Fronius Service Partner.
STATE 566 Arc detector switched off (e.g. during external arc monitoring) The STATE code is displayed every day until the arc detector is reactivated. No error
Confirm status code by pressing ‘Enter’.
STATE 567 Grid Voltage Dependent Power Reduction is active This state code is a warning informing you that the Grid Voltage Dependent Power Reduction mode (GVDPR or Volt – Watt mode) has been activated and the inverter will continue to operate with reduced power output. This is because the grid voltage has exceeded 250Vac and the GVDPR has been enabled to try to reduce the voltage rise at the inverters terminals. This mode must be enabled by default in accordance with the latest Australian Standards. Acknowledge status code; if this STATE 567 code keeps recurring contact your local solar power system installer.
Find out more about the STATE 567 message here

Fronius Symo fault codes beginning with 6xx

Code
Description
Behaviour
Remedy
STATE 601 CAN bus is full The inverter is not feeding any energy into the grid. Update the inverter firmwarewith the latest firmware here; if the STATE code is displayed all the time after the firmware update contact your local Fronius Service Partner.
STATE 603 AC module temperature sensor faulty (L3) The inverter will automatically attempt to connect again and, if possible, will resume feeding energy into the grid. If this STATE code keeps recurring contact your solar power system installer.
STATE 604 DC module temperature sensor faulty
STATE 607 RCMU error The inverter is not feeding any energy into the grid. Reset status code by pressing ‘Enter’. The inverter resumes the feeding of energy into the grid; if the status code keeps appearing, check the complete solar system for damage.
STATE 608 Functional incompatibility (one or more PC boards in the inverter are not compatible with each other, e.g. after a PC board has been replaced) Update the inverter firmwarewith the latest firmware here; if the STATE code is displayed all the time after the firmware update contact your local Fronius Service Partner.

Fronius Symo fault codes beginning with 7xx

Code
Description
Behaviour
Remedy
STATE 701-716 Provides information about the internal processor status Warning message is shown on the display If the STATE code is displayed all the time notify your local Fronius Service Partner.
STATE 721 EEPROM has been re-initialised Acknowledge STATE code; If the STATE code is displayed all the time contact your local Fronius Service Partner
STATE 722-730 Provides information about the internal processor status If the STATE code is displayed all the time contact your local Fronius Service Partner
STATE 731 Initialisation error – USB flash drive is not supported Check or replace USB flash drive. Check the file system on the USB flash drive. If the STATE code is displayed all the time notify your local Fronius Service Partner.
STATE 732 Initialisation erro – Over current on USB stick
STATE 733 No USB flash drive connected Connect or check the USB flash drive. If STATE code is displayed all the time contact your local Fronius Service Partner.
STATE 734 Update file not recognised or not present Check update file (e.g. for correct file name). If STATE code is displayed all the time contact your local Fronius Service Partner.
STATE 735 Update file does not match the device, update file too old Warning message appears on the display, update process is interrupted. Check the update file with the latest firmware here; if the STATE code is displayed all the time after the firmware update contact your local Fronius Service Partner.
STATE 736 Write or read error occurred Warning message is shown on the display Check USB flash drive and the data contained on it or replace USB flash drive.
Never unplug a USB flash drive if the ‘Data Transmission’ LED is still flashing or lit.
If the STATE code is displayed all the time contact your local Fronius Service Partner.
STATE 737 File could not be opened Remove and then reinsert USB flash drive; check or replace USB flash drive
STATE 738 Log file cannot be saved (e.g. USB flash drive is write protected or full) Create storage space, remove write protection, check or replace USB stick if necessary.
If STATE code is displayed all the time contact your local Fronius Service Partner.
STATE 740 Initialisation error-error in file system on USB flash drive Check USB flash drive; reformat on PC for FAT12, FAT16 or FAT32.
STATE 741 Error during recording of logging data Remove and then reinsert USB flash drive; check or replace USB flash drive
STATE 743 Error occurred during update process Repeat the update process, check USB stick. If STATE code is displayed all the time contact your local Fronius Service Partner.
STATE 745 Update file corrupt Warning message appears on the display, update process is interrupted. Re-download update file. If STATE code is displayed all the time contact your local Fronius Service Partner.
STATE 746 Error occurred during update process Wait for 2 minutes, then start the update again. If STATE code is displayed all the time contact your local Fronius Service Partner.
STATE 751 Time lost Warning message is shown on the display Reset the time and date on the inverter. Check update file (e.g. for correct file name). If STATE code is displayed all the time contact your local Fronius Service Partner.
STATE 752 Real Time Clock module communication error
STATE 753 Internal error: Real Time Clock module is in emergency mode Time may be inaccurate or lost (feeding energy into the grid normal)
STATE 754-755 Provides information about the processor status Warning message on the display If STATE code is displayed all the time contact your local Fronius Service Partner.
STATE 757 Hardware error in the Real Time Clock module Error message is shown on the display; the inverter is not feeding any energy into the grid.
STATE 758 Internal error: Real Time Clock module is in emergency mode Time may be inaccurate or lost (feeding energy into the grid normal). Reset time and date on the inverter
STATE 760 Internal hardware error Error message is shown on the display. If STATE code is displayed all the time contact your local Fronius Service Partner.
STATE 761-765 Provides information about the internal processor status Warning message is shown on the display.
STATE 766 Emergency power de-rating has been activated Error message is shown on the display.
STATE 767 Provides information about the internal processor status Warning message is shown on the display.
STATE 768 Different power limitation in the hardware modules
STATE 772 Storage unit not available
STATE 773 Software update group 0 (invalid country setup)
STATE 775 PMC power stage set not available Warning message is shown on the display. Press ‘Enter’ key to acknowledge error. If STATE code is displayed all the time contact your local Fronius Service Partner.
STATE 776 Invalid device type
STATE 781-794 Provides information about the internal processor status Warning message is shown on the display. If STATE code is displayed all the time contact your local Fronius Service Partner.