This is the complete fault table for the Voltronic Axpert KING II TWIN Inverter family — 33 codes shared by 2 model numbers, transcribed from the official manual. On Voltronic units, a fault code means the unit has cut its output and the red LED stays solid; a warning flashes the red LED while the unit keeps running.
Last checked against the official manuals on July 27, 2026.
Fault code 01 shown on the display with the fault icon on: Fan is locked when inverter is off..
CauseFan fault.
Recommended fixReplace the fan.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 36axpert-king-ii-twin-manual-20220915-manual.pdf· page 43
Fault code 02 shown on the display with the fault icon on: Over temperature.
CauseInternal temperature of inverter component is over 100°C.
Recommended fixCheck whether the air flow of the unit is blocked or whether the ambient temperature is too high.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 36axpert-king-ii-twin-manual-20220915-manual.pdf· page 43
Fault code 03 shown on the display with the fault icon on: Battery voltage is too high.
CauseBattery is over-charged.
Recommended fixReturn to repair center.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 36axpert-king-ii-twin-manual-20220915-manual.pdf· page 43
Fault code 04 shown on the display with the fault icon on: Battery voltage is too low.
CauseBattery voltage is too low.
Recommended fixRestart the unit. If the fault happens again, contact your installer or the repair centre.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 36
Fault code 05 shown on the display with the fault icon on: Output short circuited or over temperature is detected by internal converter components..
CauseOutput short circuited.
Recommended fixCheck if wiring is connected well and remove abnormal load.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 36axpert-king-ii-twin-manual-20220915-manual.pdf· page 43
Fault code 06 shown on the display with the fault icon on: Output voltage is too high..
CauseOutput abnormal (Inverter voltage below than 190Vac or is higher than 260Vac).
Recommended fix1. Reduce the connected load. 2. Return to repair center.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 36axpert-king-ii-twin-manual-20220915-manual.pdf· page 43
Fault code 07 shown on the display with the fault icon on: Overload time out.
CauseOverload error. The inverter is overload 110% and time is up.
Recommended fixReduce the connected load by switching off some equipment.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 36axpert-king-ii-twin-manual-20220915-manual.pdf· page 43
Fault code 08 shown on the display with the fault icon on: Bus voltage is too high.
CauseInternal components failed.
Recommended fixReturn to repair center.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 36axpert-king-ii-twin-manual-20220915-manual.pdf· page 43
Fault code 09 shown on the display with the fault icon on: Bus soft start failed.
CauseInternal components failed.
Recommended fixReturn to repair center.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 36axpert-king-ii-twin-manual-20220915-manual.pdf· page 43
Fault code 50 shown on the display with the fault icon on: PFC over current.
CausePFC over current or surge.
Recommended fixRestart the unit, if the error happens again, please return to repair center.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 36axpert-king-ii-twin-manual-20220915-manual.pdf· page 43
Fault code 51 shown on the display with the fault icon on: OP over current.
CauseOP over current or surge.
Recommended fixIf the battery is connected well, please return to repair center.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 36axpert-king-ii-twin-manual-20220915-manual.pdf· page 43
Fault code 52 shown on the display with the fault icon on: Bus voltage is too low.
CauseBus voltage is too low.
Recommended fixIf the battery is connected well, please return to repair center.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 36axpert-king-ii-twin-manual-20220915-manual.pdf· page 43
Fault code 53 shown on the display with the fault icon on: Inverter soft start failed.
CauseInternal components failed.
Recommended fixReturn to repair center.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 36axpert-king-ii-twin-manual-20220915-manual.pdf· page 43
Fault code 55 shown on the display with the fault icon on: Over DC voltage in AC output.
CauseOutput voltage is unbalanced.
Recommended fixIf the battery is connected well, please return to repair center.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 36axpert-king-ii-twin-manual-20220915-manual.pdf· page 43
Fault code 57 shown on the display with the fault icon on: Current sensor failed.
CauseInternal components failed.
Recommended fixReturn to repair center.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 36axpert-king-ii-twin-manual-20220915-manual.pdf· page 43
Fault code 58 shown on the display with the fault icon on: Output voltage is too low.
CauseOutput abnormal (Inverter voltage below than 190Vac or is higher than 260Vac).
Recommended fix1. Reduce the connected load. 2. Return to repair center.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 36axpert-king-ii-twin-manual-20220915-manual.pdf· page 43
Fault code 60 shown on the display with the fault icon on: Power feedback protection.
CausePower feedback protection.
Recommended fixRestart the unit. If the fault happens again, contact your installer or the repair centre.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 57
Fault code 71 shown on the display with the fault icon on: Firmware version inconsistent.
CauseFirmware version inconsistent.
Recommended fixRestart the unit. If the fault happens again, contact your installer or the repair centre.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 57
Fault code 72 shown on the display with the fault icon on: Current sharing fault.
CauseCurrent sharing fault.
Recommended fixRestart the unit. If the fault happens again, contact your installer or the repair centre.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 57
Fault code 80 shown on the display with the fault icon on: CAN fault.
CauseCAN fault.
Recommended fixRestart the unit. If the fault happens again, contact your installer or the repair centre.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 57
Fault code 81 shown on the display with the fault icon on: Host loss.
CauseHost loss.
Recommended fixRestart the unit. If the fault happens again, contact your installer or the repair centre.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 57
Fault code 82 shown on the display with the fault icon on: Synchronization loss.
CauseSynchronization loss.
Recommended fixRestart the unit. If the fault happens again, contact your installer or the repair centre.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 57
Fault code 83 shown on the display with the fault icon on: Battery voltage detected different.
CauseBattery voltage detected different.
Recommended fixRestart the unit. If the fault happens again, contact your installer or the repair centre.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 57
Fault code 84 shown on the display with the fault icon on: AC input voltage and frequency detected different.
CauseAC input voltage and frequency detected different.
Recommended fixRestart the unit. If the fault happens again, contact your installer or the repair centre.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 57
Fault code 85 shown on the display with the fault icon on: AC output current unbalance.
CauseAC output current unbalance.
Recommended fixRestart the unit. If the fault happens again, contact your installer or the repair centre.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 57
Fault code 86 shown on the display with the fault icon on: AC output mode setting is different.
CauseAC output mode setting is different.
Recommended fixRestart the unit. If the fault happens again, contact your installer or the repair centre.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 57
Warning code 01 flashing on the display: Fan is locked when inverter is on.. Audible alarm: beep three times every second.
CauseFan is locked when inverter is on.
Recommended fixReplace the fan.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 36
Warning code 02 flashing on the display: Over temperature.
CauseOver temperature.
Recommended fixCheck whether the air flow of the unit is blocked or whether the ambient temperature is too high.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 36
Warning code 03 flashing on the display: Battery is over-charged. Audible alarm: beep once every second.
CauseBattery is over-charged.
Recommended fixReturn to repair center.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 36
Warning code 04 flashing on the display: Low battery. Audible alarm: beep once every second.
CauseLow battery.
Recommended fixThe unit keeps operating. Clear the condition shown and the warning resets automatically; if it persists, contact your installer or the repair centre.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 36
Warning code 07 flashing on the display: Overload. Audible alarm: beep once every 0.5 second.
CauseOverload.
Recommended fixReduce the connected load by switching off some equipment.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 36
Warning code 10 flashing on the display: Output power derating. Audible alarm: beep twice every 3 seconds.
CauseOutput power derating.
Recommended fixThe unit keeps operating. Clear the condition shown and the warning resets automatically; if it persists, contact your installer or the repair centre.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 36
Warning code 32 flashing on the display: Communication interrupted.
CauseCommunication interrupted.
Recommended fixThe unit keeps operating. Clear the condition shown and the warning resets automatically; if it persists, contact your installer or the repair centre.
Source:axpert-king-ii-twin-manual-20220915-manual.pdf· page 36
Send us the code on your screen and a Voltronic technician will reply with the exact steps for your unit. Support is free for life — a first diagnosis never needs a callout.
Compiled from official Voltronic user manuals. Always consult your device manual and a qualified technician before performing repairs.