Fronius Class 4 State Error Codes

Fronius class 4 state errors require the intervention of a Fronius Service Partner. They are either temporary or lasting and are triggered by faulty hardware or a software problem. Try switching off the Fronius inverter following the system shutdown procedure, leave off for a few minutes then attempt to restart. If the fault continues please contact your local Fronius Service Partner for further assistance.

Code	Description	Behavior	Remedy
STATE 401	No communication with power stage set possible	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	Power stage set temperature sensor faulty
STATE 407	Internal temperature sensor faulty
STATE 408	DC feeding into the grid detected
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 the 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
STATE 419	Unique ID conflict
STATE 421	HID range error
STATE 425	No communication possible with the power stage set
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 the 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 firmware; if this status code is displayed all the time please 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	Invalid limit value settings	The inverter is not feeding any energy into the grid for safety reasons.	Update the inverter firmware with the latest firmware here; if the STATE code is displayed all the time after the firmware update contacts 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 452	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	Short term grid voltage error
STATE 454	Short term grid frequency error
STATE 456	An anti-islanding function is no longer implemented correctly
STATE 457	Grid relay sticking	The inverter is not feeding any energy into the grid.	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		If this STATE code keeps recurring, contact your solar power system installer
STATE 475	Solar panel ground fault, insulation fault (the 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 firmware with the latest firmware here; if the STATE code persists contact your local Fronius Service Partner
STATE 482	Startup incomplete		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.