The Complete Guide To Kstar Inverter Error Codes

On a BluE-G, KSG or BluE three-phase string inverter, F00 to F03 are the grid voltage or frequency going outside the limits; the inverter disconnects and reconnects itself when the grid is steady. On a BluE-S hybrid F00 is Soft Time Out, an internal software timeout that a restart clears. Either way it is only a concern if it keeps coming back.

On a BluE-S hybrid, F01 INV Volt Short means a short circuit on the inverter's output, usually a faulty appliance or wiring on the backup circuit; Kstar wants the load disconnected and the inverter restarted to see if the short has gone, an electrician's job. On a BluE-G, KSG or three-phase string inverter F01 is just a grid voltage or frequency trip that clears itself. Over-voltage, over-current and short-circuit faults can damage hardware, so we treat them as a call.

On the BluE-G, KSG and BluE three-phase string inverters, F03 is the last of the F00 to F03 group: the grid voltage or frequency went outside the limits and the inverter disconnected. It reconnects by itself; Kstar's own steps are to check the mains is normal and the AC wiring is tight, then restart. The BluE-S hybrid has no F03.

The mains voltage at the inverter dropped below the limit it is allowed to run at, so the BluE-S hybrid stopped exporting. It reconnects by itself within a couple of minutes once the grid is steady; if it keeps coming back the AC run or the street voltage needs checking.

The mains voltage at the inverter went above the limit it is allowed to export at, so the BluE-S hybrid disconnected. It reconnects itself; if it happens most sunny afternoons the cable run is too thin or the street voltage is high and the network may need to be told.

W02 is grid frequency low and W03 grid frequency high: the grid frequency went outside the inverter's limits for a moment and the BluE-S hybrid disconnected. It reconnects by itself once the grid is steady.

On the BluE three-phase string inverters, W03 Zero Power Alarm means the unit is on but producing nothing. Normal at dawn and dusk; in good sun it points to a string problem or to an export meter that has stopped talking, which makes the inverter limit itself to zero. On a BluE-S hybrid W03 is grid frequency high instead, listed under W02.

On a BluE-S hybrid, F08 PV Input Short Circuit means a short across a string input, usually a damaged DC cable, a crushed connector or a wrongly wired string. On a BluE-G, KSG or three-phase string inverter F08 is Input Current High, more current from a string than the input is rated for. Both start with the PV input mode setting, then a restart, then an installer if it returns.

The inverter's output current went above its rating for a moment, on a hybrid usually a large appliance starting on the backup circuit, on a string inverter a grid disturbance. Kstar says wait five minutes for it to restart itself and check the load is within the specification. Only a concern if it keeps returning. Over-voltage, over-current and short-circuit faults can damage hardware, so we treat them as a call.

On a BluE-S hybrid, F15 Dischg Curr Over means the battery was asked to discharge harder than its limit, usually a heavy load during a blackout; Kstar says wait a minute for the restart and check the load. On a BluE-G, KSG or three-phase string inverter F15 is PV Input Voltage Low: not enough string voltage to start, normal at dawn and dusk, or one input left empty in parallel mode. Over-voltage, over-current and short-circuit faults can damage hardware, so we treat them as a call.

An IGBT, one of the power switching modules inside a BluE-G, KSG or three-phase string inverter, has failed its check. This is a hardware failure of the main power stage: one restart to confirm, then a service call, and on an older unit it often means replacement.

On a BluE-S hybrid, Solar Loss means the inverter cannot see any voltage from the panels: normal at night and in heavy cloud, a problem if it is still there on a sunny morning (rooftop DC isolator off, a string unplugged). On the BluE three-phase string inverters W04 is String Alarm: one string has no voltage or is reversed or unbalanced against the others.

The appliances the BluE-S hybrid is supplying are drawing more than it is rated for, most often during a blackout when an air conditioner, oven, pump or kettle start together on the backup circuit. Switch the heavy appliances off and it retries itself after about a minute; if it trips with little connected the wiring or settings need checking.

The BluE-S hybrid has found the active and neutral wires on its AC side the wrong way round (the older manual calls it LN Fault). It is an installation wiring error, not something that happens by itself, and the inverter will not run properly until an electrician corrects it.

On a BluE-S hybrid, F02 GFCI Sensor Fault means the sensor that watches for current leaking to earth has failed its self-test; the inverter will not run without it. Kstar's step is a full power-off restart, then service if it returns. On a BluE-G, KSG or three-phase string inverter F02 is just a grid voltage or frequency trip that clears itself. Anything to do with earth or leakage current is a safety fault, so we treat it as a call.

The inverter found too little insulation between the solar wiring and earth, usually water in a rooftop connector or isolator, a chafed cable or a damaged panel. Kstar wants each string's resistance to earth measured (above 2 megohm on the BluE-S hybrid, above 500 kilohm on the BluE-G). A morning alarm that clears by midday points to dew; one that stays is an electrical safety issue.

On a BluE-G, KSG or three-phase string inverter, F20 Leakage Current High (installers call it GFCI Fault) means current is leaking to earth from the solar wiring, usually water in a connector or a damaged cable, and an electrician needs to find it. On a BluE-S hybrid F20 Alway Over Load means the backup load has stayed above the rating: switch off heavy appliances and have the installer review it.

The BluE-G, KSG or three-phase string inverter could not verify its own earth leakage sensor at start-up, so it will not run. Kstar's step is a restart with the PV disconnected, then the distributor if it returns; it is a board-level fault.

The BluE three-phase string inverter measured too much voltage between neutral and earth, which usually means the inverter's earth is not bonded to the grid earth or there is a loose neutral. It is a wiring matter for an electrician, not something a restart fixes.

On a BluE-S hybrid, GFCI Over means the inverter measured more current leaking to earth than is safe, usually water in a rooftop connector or isolator, a damaged cable or a faulty panel; Kstar wants the strings checked for an earth fault, an electrician's job. On a BluE three-phase string inverter W10 is Poor Grid Quality, a distorted supply waveform for the network, not the inverter, to fix.

The air around the inverter is hotter than it is rated for, so it has shut down until it cools. Common on a west-facing wall or in a closed garage on a hot afternoon. Kstar's step is to let it cool, restart, and check the installation spot; it is a problem only if it happens most hot days. Heat shutdowns point at a failing fan, a blocked vent or a bad installation spot, so we treat them as a call.

The inverter's heat sink has gone over its limit, so it has shut down until it cools. Usually a hot day plus a blocked or failed fan, dust on the fins, or no clearance around the unit. It restarts itself once cool; if it happens often the fan or the location needs attention. Heat shutdowns point at a failing fan, a blocked vent or a bad installation spot, so we treat them as a call.

The inverter's cooling fan is not turning or is turning too slowly, so the unit will run hot and cut its output on warm days. On a BluE-S hybrid this is W12 Fan Fault; on the BluE three-phase string inverters W17, W18, W19 and W22 are the individual fans running slow, usually blocked by insects, dust or a loose plug. The inverter keeps working but the fan needs cleaning or replacing. A fan fault lets the inverter overheat, so we treat it as a call.

The internal DC bus that joins the panels, battery and grid stages has dropped below where it should be. Kstar's first step on both the hybrid and the string inverters is to check the PV input mode setting matches how the strings are wired, then restart. One trip at dawn or at a blackout switch-over can be ignored; a repeat is an internal or wiring fault for the installer.

The internal DC bus voltage went above its limit, usually because the string voltage is too high for the input mode set, or a stage inside the inverter has failed. Kstar's step is to check the input mode setting and restart; if it comes back it is an installer job.

On a BluE-S hybrid, F06 Bus Short Circuit means the inverter detected a short on its internal DC bus, a hardware fault. On a BluE-G, KSG or three-phase string inverter F06 is Bus voltage unbalance, where the two halves of the bus are uneven, usually an input mode mismatch or a failing stage. Both call for a restart and then an installer if it returns.

On a BluE-S hybrid, F09 Bypass Relay Fault means the relay that switches the backup circuit between grid and inverter failed its check; the older manual calls it Op Relay Fail. On a BluE-G, KSG or three-phase string inverter F09 is Hardware Current High, a fast over-current trip inside the unit. Kstar's step for both is a restart after a few minutes, then service if it returns.

The inverter measured too much direct current mixed into its AC output, which the grid rules do not allow, so it disconnected. A one-off clears with a restart; if it keeps happening the output stage or its sensing needs checking by the installer. DC on the AC side is a protection fault, so we treat it as a call.

The relay that connects the inverter to the grid failed its self-test, so the inverter will not export. On a BluE-G or three-phase string inverter Kstar also says to check that no phase is missing. A relay that has welded or worn is an internal repair; a restart is worth one try before the visit.

A current sensor inside the BluE-S hybrid has failed its self-check, so the inverter cannot measure what it is doing and stops. Kstar's step is a restart, then service if it returns; it is a board-level repair, not something that can be fixed on the wall.

On a BluE-S hybrid, F18 INV Abnormal is a general internal fault; Kstar's only instruction is to contact the distributor. On a BluE-G, KSG or three-phase string inverter F18 is SPI communication Fault, the two processors on the control board no longer talking. Both are board-level faults: one restart, then a service call.

On a BluE-S hybrid, F19 EPS Relay Fault means the relay that feeds the backup circuit during a blackout has failed, so backup will not work until it is repaired; solar and grid supply usually continue. On the older KSG string inverters an Australian installer lists F19 as a communication fault on the control board. Either way it is a service call.

The two processors inside a BluE-G, KSG or three-phase string inverter disagree about the grid voltage (F22) or frequency (F23) they are measuring, so the unit stops as a safety precaution. A restart clears a one-off; if it repeats a sensing circuit has drifted and it is a service call.

On a BluE-G or KSG single-phase string inverter, F24 DSP Operation Fault means the main processor has stopped running properly. On the BluE three-phase units the newer manual lists F24 as Isolated island Fault, the inverter detecting it was feeding a dead grid and shutting down. Kstar's step for both is a restart, then the distributor if it returns.

The boards inside the inverter have stopped talking to each other: SCI Fault or Communication Fault on a BluE-S hybrid, DSP communication Lost on a BluE-G, KSG or three-phase string inverter. The unit stops until it is cleared. Kstar's step is a restart, then the distributor if it returns; it is a control board repair.

The current clamp (CT) that tells the BluE-S hybrid which way power is flowing at the switchboard is reading backwards, so the inverter thinks you are importing when you are exporting. Self-consumption and export limiting will behave oddly until it is turned round. Kstar's step is a CT self-check from the installer menu. A failed self-test means the inverter cannot prove its own protection works, so we treat it as a call.

The BluE-S hybrid's internal clock failed to start, which upsets the daily energy figures and any time-of-use charging schedules but does not stop solar or the battery. A restart usually clears it; if it keeps happening the clock battery on the board is flat, which is a service job. Internal and hardware faults need testing with the right instruments, so we treat them as a call.

On a BluE-S hybrid, F16 Chg Curr Over means the battery was being charged above its limit; Kstar wants the battery wiring checked for a short and the charge current setting checked against the preset. On a BluE-G, KSG or three-phase string inverter F16 is Remote Off: the unit has been switched off through the monitoring software and only the monitoring or the installer can switch it back on. Over-voltage, over-current and short-circuit faults can damage hardware, so we treat them as a call.

On a BluE-S hybrid, Bat Loss means the inverter cannot see the battery: the battery is switched off, its breaker has tripped, or the battery cable or plug is loose or shorted. Solar still works but there is no storage until it is fixed. On a BluE three-phase string inverter W05 is Derating Due to Overtemperature: the unit is running hot and has cut its output until it cools. Heat shutdowns point at a failing fan, a blocked vent or a bad installation spot, so we treat them as a call.

On a BluE-S hybrid, Bat Under Volt means the battery voltage has dropped below its working range, usually after being run flat or left off for a long time; it needs to charge from solar or grid, and if it will not recover the battery needs checking. On a BluE three-phase string inverter W06 is an SPD Alarm: the surge protection inside has been damaged by lightning or its sensing wire is off. Internal and hardware faults need testing with the right instruments, so we treat them as a call.

On a BluE-S hybrid, Bat Volt Low means the battery is nearly empty, so backup and night-time discharge stop until it charges again. Normal after a cloudy run or a long blackout; a problem if it never recovers. On a BluE three-phase string inverter W07 is PV Parallel Disconnection: the input mode is set to parallel but one of the paired inputs has no string on it.

The battery voltage is above the range the BluE-S hybrid expects, which usually means the battery type or voltage settings in the inverter do not match the battery fitted, or the battery is being overcharged. Kstar's own steps are to check the battery matches the preset, then power off and restart.

The BluE-Pack battery has switched itself off, which it does to protect its cells after running flat or sitting unused. The BluE-S hybrid keeps running on solar and grid but has no storage until the battery wakes. Kstar's manual lists the code without a description; the fix is a restart and, if it stays off, a visit.

The battery's own management system (BMS) has reported that it was being charged (W15) or discharged (W14) harder than it allows, so it has cut back or stopped for a moment. A one-off during a heavy load or a cold morning is nothing to worry about; repeated warnings mean the inverter's current limits do not match the battery. Battery protection faults are not something to ride out at home, so we treat them as a call.

The battery management system has reported a cell or pack voltage above its limit (W16), or well above it (W23 BMS Severe Over Volt). It stops charging to protect itself; if it repeats, the charge settings or the battery need checking. On a BluE three-phase string inverter W16 is only an RTC Operation Alarm, the internal clock, which a restart usually clears. Over-voltage, over-current and short-circuit faults can damage hardware, so we treat them as a call.

The battery management system has reported the battery is too hot and has paused charging or discharging until it cools. Common on a hot afternoon in a garage or a sunny wall; it clears on its own as the battery cools. If it happens most days the battery is in the wrong spot or something is wrong inside it. Heat shutdowns point at a failing fan, a blocked vent or a bad installation spot, so we treat them as a call.

The battery is below the temperature its management system allows for discharging (W18) or charging (W22), so it waits until it warms up. The BluE-Pack has a built-in heating film and this clears on its own on a winter morning. The hybrid keeps running on solar and grid in the meantime.

The cells inside the battery are at noticeably different voltages, so the battery management system limits charging and discharging while it balances them. Usually clears after a few full charges on sunny days; if it keeps coming back a module is weak and the battery needs checking under warranty.

The BluE-S hybrid cannot talk to the battery's management system over the communication cable, so it cannot charge or discharge safely and the battery sits idle. Usually a loose CAN cable or plug, the wrong battery type selected, or the battery switched off. Solar and grid supply keep working.

The battery management system has reported a cell below its minimum voltage, usually after the battery has been run flat and left. It blocks discharge until the battery has charged from solar or grid. If a sunny day does not clear it, a cell or module may be failing.

The battery management system has reported a temperature well above its safe limit and has shut the battery down. Unlike the ordinary over-temperature warning this one should be looked at promptly: do not cover or move the battery, keep the area clear, and if there is any smell or smoke call the fire brigade before anyone else.

W25 BMS Updating means the battery's firmware is being updated and it is unavailable for a while; let it finish. W26 BMS Program Version Err means the battery firmware does not match what the inverter expects, and W27 BMS Program Update Fail means an update did not complete. Those two need the installer or Kstar to push the right firmware.