Fronius Inverter Error Codes

Code Description What to do
101 Grid voltage beyond permitted limits Check grid voltage; ensure circuit breakers ON. If persists, contact Fronius Service Partner.
102 AC voltage too high Check grid voltage and settings; if still occurring, contact Fronius Service Partner.
103 AC voltage too low Check grid voltage; if persists contact Fronius Service Partner.
104 Mains frequency beyond permitted limits Check grid frequency and service-menu values; if unresolved, contact Fronius Service Partner.
105 AC frequency too high Contact original installer or Fronius Service Partner.
106 AC frequency too low Contact original installer or Fronius Service Partner.
107 AC grid outside allowed limits Contact installer or Fronius Service Partner.
108 Independent (island) operation detected Contact installer / Fronius Service Partner.
112 Residual Current Monitoring Unit (RCMU) error Contact installer / Fronius Service Partner.
141 Grid frequency jump too high Contact installer / Fronius Service Partner.
301 AC output over-current Usually auto-resolves; if continuous, restart system and if still persists contact Fronius Service Partner.
302 DC input over-current Usually auto-resolves; if continuous, restart system and contact Fronius Service Partner.
303 DC module or board overheating Ensure ventilation unobstructed; if persists contact Fronius Service Partner.
304 AC module (heat-sink) overheating Ensure ventilation; if continues contact Fronius Service Partner.
305 Power not fed in though relay is closed Usually auto-resolves; if persistent contact Fronius Service Partner.
306 PV output too low to feed (morning/evening low sun) If occurs during sufficient sunlight, contact Fronius Service Partner.
307 PV voltage too low to feed Same as above.
308 Intermediate circuit over-voltage Usually auto-resolves; if persistent contact Fronius Service Partner.
309 DC input voltage MPPT1 too high If recurring, contact Fronius Service Partner.
313 DC input voltage MPPT2 too high If recurring, contact Fronius Service Partner.
314 Current sensor calibration timeout Try restart; if persists contact Fronius Service Partner.
315 AC current sensor error Contact installer / Fronius Service Partner.
316 Interrupt check fail (internal) Contact installer / Fronius Service Partner.
317 Unbalanced intermediate circuit voltage Contact Fronius Service Partner.
318 DC back-current detected Contact installer / Fronius Service Partner.
325 Connection area overheating Contact installer / Fronius Service Partner.
326 Fan 1 error Contact installer / Fronius Service Partner.
327 Fan 2 error Contact installer / Fronius Service Partner.
401 No communication with power stage set If persists, contact Fronius Service Partner.
406-407 Temperature sensor faults (AC/DC) Contact Fronius Service Partner.
408 DC component detected in grid Contact Fronius Service Partner.
412 Fixed voltage mode selected instead of MPP mode If persists, contact Fronius Service Partner.
415 Safety cut-out triggered via option card or REC ERBO If persists, contact Fronius Service Partner.
416-419 Hardware/communication ID issues Usually firmware update required; if continues contact Fronius Service Partner.
421 HID range error If persists, contact Fronius Service Partner.
425-428 Communication fault / hardware fault Firmware update and if still persists contact Fronius Service Partner.
431 Software fault Try AC reset (turn breaker off/on); if persists contact Fronius Service Partner.
436-438 Functional incompatibility / PC board incompatibility Firmware update; if persists contact Fronius Service Partner.
443 Intermediate circuit voltage too low or asymmetric If persists contact Fronius Service Partner.
445 Invalid limit value settings Update firmware; if persists contact Fronius Service Partner.
447 Insulation fault Contact installer / Fronius Service Partner.
448 Neutral conductor not connected If persists contact Fronius Service Partner.
450 Guard can’t be found If persists contact Fronius Service Partner.
452 Memory/communication fault Contact installer / Fronius Service Partner.
453 Power stage set & grid voltage not compatible Restart system and monitor; if persistent contact Fronius Service Partner.
454 Power stage set & grid frequency not compatible Restart system; if persists contact Fronius Service Partner.
456 Anti-islanding function no longer implemented correctly Restart and monitor; if persists contact Fronius Service Partner.
457 Grid relay sticking or neutral conductor ground voltage too high Check grounding (< 30 V) and contact Fronius Service Partner.
460-462 DSP reference voltage or monitoring routine fault Restart; if persists contact Fronius Service Partner.
463 Reversed AC polarity Check AC connector; if persists contact Fronius Service Partner.
474 RCMU sensor faulty Contact installer / Fronius Service Partner.
475 Insulation fault / solar panel to ground fault Immediately contact installer / Fronius Service Partner.
480-481 Functional incompatibility (PC boards) Firmware update; if persists contact Fronius Service Partner.
482 Startup incomplete Perform full AC-reset; if persists contact Fronius Service Partner.
483 UDC fixed voltage on MPP2 string out of limits Check MPP settings; if persists contact Fronius Service Partner.
502 Insulation error on solar panels If persists, contact installer / Fronius Service Partner.
509 No energy fed into grid in last 24 h Ensure grid/panel conditions fine; if persists for 2+ days contact Fronius Service Partner.
515-516 Communication with filter/storage unit fault If persists, contact installer / Fronius Service Partner.
517-523 PV strings low/no feed or communication fault Check ventilation, DC input, restart system; if persists contact Fronius Service Partner.
560 Grid frequency too high causing derating Usually resolves automatically; monitor system and if frequent, contact Fronius Service Partner.
601-609 CAN bus full, sensor faults, configuration out of limits Requires firmware, if persists contact Fronius Service Partner.
700-794 Internal processor, USB, firmware update or memory fault codes If persists contact Fronius Service Partner.
1001, 1024, 1030, 1112, 1175 (For GEN24 models) e.g. insulation measurement triggered, settings changed, grid frequency exceeded limit, low DC power Follow in-display advice; if unresolved contact installer / Fronius Service Partner.