The Complete Guide To Error Codes On Older Inverter Brands

The mains voltage went above (AL00) or below (AL01) the inverter's limits, so it disconnected. It restarts by itself about a minute after the grid is back in range.

The mains frequency went above (AL02) or below (AL03) the inverter's limits, so it disconnected. It restarts by itself once the grid settles.

The solar input voltage on string A (AL04, AL05) or string B (AL06, AL07) is outside the 120 to 500 V range. Too high on a cold bright morning or too low with a string open are the usual causes.

The inverter cannot see the mains (anti-islanding). A tripped solar supply main switch, a blackout or a loose AC connection are the usual causes.

The inverter's output waveform is out of balance. The manual's fix is a shutdown and restart after checking the grid; a repeat is an internal fault. Internal and hardware faults need testing with the right instruments, so we treat them as a call.

Current is leaking to earth above the inverter's limit (GFDI), so it stopped. That points to a wet or damaged part of the DC side or a fault on the AC side.

The inverter measured less than 1 megohm between the solar array and earth, so it stopped. Water in a roof connector or a damaged cable is the usual cause.

The inverter did not like the shape (AL14) or phase (AL13) of the mains it saw, so it disconnected. It usually reconnects by itself; a repeat needs the AC connection checked.

The inverter's internal DC bus would not charge up at start, which points to a failed capacitor or power board. The manual allows one disconnect and reconnect, then service.

The inverter's own output voltage is wrong, an internal power-stage fault. Service if it recurs.

The inverter is in emergency power-off mode, usually because the EPO terminal has been shorted or a connected shutdown device has tripped.

The inverter's internal DC bus is higher (Er07) or lower (Er08) than it should be. If the string voltage is within range, it is an internal fault.

The inverter measured too much current on its AC output (Er09), an overload (Er11) or a short circuit (Er13). The manual says switch off the AC breaker and have the AC side and grid checked.

The inside of the inverter (Er10) or its heat sink (Er18) got too hot. Blocked airflow or a hot mounting spot is the usual cause; it restarts once it cools. Heat shutdowns point at a failing fan, a blocked vent or a bad installation spot, so we treat them as a call.

The inverter cannot lock its output to the mains waveform (PLL fail). The manual's only advice is to contact the distributor, so treat it as an internal fault.

The settings memory on the control board is corrupt (Er17), or it no longer matches the driver board (Er30). It is a board fault rather than anything outside the unit.

The capacitors on the inverter's internal DC bus will not discharge, an internal power board fault.

The relay that connects the inverter to the grid has failed its test. It is an internal hardware fault and the unit stays off.

The sensor that measures the inverter's output current has failed, an internal hardware fault.

More current than the inverter is rated for came in on string A (Er25) or string B (Er26). If the array matches the inverter, it is an internal fault.

The inverter is pushing too much direct current into the grid. The manual's only advice is to contact the distributor; a repeat is a drifting output stage. DC on the AC side is a protection fault, so we treat it as a call.

The inverter has no power at all. On a sunny day that means the supply has been cut by a tripped switch or isolator, or the inverter's own power supply has failed, a known weak point on these units.

On a Latronics PVE the 50% or 75% light flashing or staying on means the grid is out of range or the unit is still checking the mains before it connects. The 75% light flashing for about a minute after switch-on is normal; staying on with no production means the AC side is not live.

The 100% light means the inverter is at or over its limit, which should only happen briefly in ideal sun. If it stays on, or the unit is loud, it is working outside its rating.

Latronics PVE units have no screen, so an earth or insulation problem shows only as the unit refusing to run or tripping the switchboard. An insulation fault means current can leak from the array to earth, which is a safety issue.

A Latronics PVE has no screen, only lights. No lights at all on a sunny day means the supply has been cut by a tripped switch or isolator, or the inverter has failed. The manual's reset is to switch the DC and AC isolators off for 60 seconds, then DC on, then AC on.

The relay that connects the inverter to the grid has failed, so the unit will not feed in even with sun and grid present. It is an internal fault on a brand with no fault display.

A red status light with Device error and a two-digit code, or SUPPLY FAULT, ERROR EEPROM, ADC REFERENCE ERROR or CONFIGURATION ERROR at start-up, means an internal fault in the inverter. The manual's only advice is to note the code and contact service.

A temperature sensor inside the inverter has stopped working. It is an internal fault; the manual says contact service.

The mains frequency is outside the inverter's limits or changing too fast (df/dt too high), so it disconnected. It reconnects by itself once the grid settles.

DC current leaking to earth went above the inverter's limit, so it stopped. The manual's instruction is to check the solar array.

The insulation resistance between the solar array and earth is too low, so the inverter stopped. Water in a roof connector or a damaged cable is the usual cause.

The inverter cannot see mains voltage (No mains), or it detected it was running on its own without the grid (Mains error). A tripped solar supply main switch or a blackout is the usual cause.

The manual puts a blank display down to the DC switch being off or not enough sun, and a periodically flashing display down to low light or a disconnected string. If it stays blank in full sun with the DC switch on, the inverter has failed.

SolarMax S series units report a failed grid relay as a Device error with a code rather than by name. The relay that connects the inverter to the grid has failed, an internal fault.

The inverter has cut its output to stay cool (Temperature limitation), or a fan is dirty or dead (Failure fan). Blocked fan grilles are the usual cause. Heat shutdowns point at a failing fan, a blocked vent or a bad installation spot, so we treat them as a call.

The mains voltage is above (Vac too high, Uac 10min too high) or below (Vac too low) the inverter's limits, so it disconnected. It reconnects by itself; if it keeps happening the manual says contact the grid operator.

The solar array voltage is above the inverter's maximum. The manual says open the DC switch straight away and have the string configuration checked.

The inverter switched off because it overheated. A hot spot, a covered fan or a failing unit are the manual's three causes; the first step is to clean the fans. Heat shutdowns point at a failing fan, a blocked vent or a bad installation spot, so we treat them as a call.

The inverter detected current leaking to earth and stopped feeding in. The manual says notify an electrician.

The inverter found an insulation fault on the solar array and stopped feeding in. Water in a roof connector or a damaged cable is the usual cause; the manual says call an electrician if it happens more than once.

A ground fault was detected on the solar array (the display adds Check fuse). It is a safety stop until the array is tested.

The inverter's current and voltage readings do not add up (FS 30), or its residual current module has failed (FS 31). Both are internal faults.

The internal grid separation relay failed its self-test, so the inverter will not connect. If it keeps happening the relay is defective and has to be replaced, which for this brand means the unit.

The inverter is pushing too much direct current into the grid. The manual notes the grid itself can cause it; notify an electrician if it happens several times.

An error in the inverter's internal data link. The manual says check the data cable and notify an electrician. Internal and hardware faults need testing with the right instruments, so we treat them as a call.

The inverter shut itself down to protect against an AC overvoltage, overcurrent or DC link overvoltage. The manual says this is not a fault but a grid-related shutdown; it reconnects by itself.

The solar array voltage is too high for the inverter, which the manual puts down to the array being configured wrongly. It needs an electrician to check the strings. Over-voltage, over-current and short-circuit faults can damage hardware, so we treat them as a call.

The grid voltage is too low (FS 41) or too high (FS 42), so the inverter cannot feed in. It reconnects by itself once the grid is back in range; daily repeats mean the grid voltage needs measuring.

The manual says a hum from the unit under certain grid or weather conditions is normal, does not affect operation or life, and needs no action. Children can hear its 17 kHz operating whine. A new loud buzz or rattle is different and worth a look.

The manual puts a blank display with no lights down to the grid voltage not being available at the inverter. On a sunny day with the grid live, the inverter's own power supply has failed.

Not a fault: the array voltage is too low to feed in, which is normal at dawn, dusk and in heavy cloud. The inverter starts by itself once there is enough sun.

The inverter has no power at all. On a sunny day that means the supply has been cut by a tripped switch or isolator, or the inverter's own power supply has failed.

The mains voltage is too low, so the inverter disconnected. A tripped solar supply main switch, a blackout or a loose AC connection are the usual causes; it reconnects by itself.

The mains voltage is too high on average (7 to 9), too high (10 to 15) or spiked briefly (16 to 18), so the inverter disconnected. It reconnects by itself; daily repeats mean the grid voltage at your house is running high.

The mains frequency went out of range (19 to 24), a phase-to-phase voltage dropped (25 to 27) or the frequency changed too fast (28 to 30), so the inverter disconnected. It reconnects by itself once the grid settles.

The inverter is pushing too much direct current into the grid. The manual sends a repeat to the hotline, so treat it as the output stage drifting.

The inverter detected current leaking to earth above its limit and stopped. The manual says inspect all solar cables and modules.

The mains has been out of range for more than ten minutes. A tripped solar supply main switch, a blackout or a real grid problem; the manual says check the AC installation.

The solar array is giving more current (103 to 105) or voltage (258) than the inverter allows, and it waits. The manual says check the array against the installation manual; it is a string design issue, not a grid one.

The insulation resistance between the solar array and earth is too low, so the inverter stopped and will retest in ten minutes. Water in a roof connector, a damaged cable or a missing earth are the manual's causes.

The inside of the inverter got too hot, so it is waiting to cool. Blocked airflow to the heat sink is the manual's cause. 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 internal DC bus voltage is too high (209, 210) or unbalanced (212), its internal measurements disagree (213 to 215), or the grid current is too high (216 to 218). All are internal faults the manual sends to the hotline.

The inverter gets no speed signal from its fan. The manual says check the event log and call the hotline if most events are 211. A fan fault lets the inverter overheat, so we treat it as a call.

The inverter's anti-islanding protection tripped because it could not confirm the grid was there. It reconnects by itself once the grid is back; the manual says check the grid is available.

A wire in the residual current monitoring unit is broken. The inverter will not run without it, and it is an internal fault.

The inverter found an error in its internal memory. One restart is worth trying; the manual sends a constant repeat to the hotline. Internal and hardware faults need testing with the right instruments, so we treat them as a call.

An internal communication error (241, 242, 249), an internal error (243, 244) or a failed test in the safety processor (247, 251). All are internal board faults the manual sends to the hotline.

A grid event was caught by the inverter's backup safety circuit and it stopped. The manual says check the event log: if most events are 246, contact service, otherwise wait 24 hours and look again.

The residual current monitor (350 to 352) or a current sensor (353 to 355) failed its self-test. The manual says check the solar array polarity and the AC installation; a repeat is an internal fault.

The inverter's self-test of its transistors and grid relay failed, so it will not connect. The manual says check the AC installation and that the neutral is connected; a repeat is an internal fault.

The inverter thinks something is wrong with the AC wiring, usually a missing neutral. It needs an electrician to check the installation.

The output current went above the inverter's rating. The manual says contact service if it happens often; a one-off is usually a grid disturbance.

The grid voltage, frequency or waveform quality is temporarily outside the normal range, so the inverter paused. The manual says wait: it resumes on its own and the green light goes solid.

The inverter has no power at all. On a sunny day that means the supply has been cut by a tripped switch or isolator, or the inverter's own power supply has failed.

The inverter is pushing too much direct current into the grid. The manual says contact service if it happens often. DC on the AC side is a protection fault, so we treat it as a call.

The residual current monitor tripped on steady leakage to earth or a sudden change in it. The manual says have an installer check the array for ground faults.

The link between the main processor and the display (COMM1) or the backup controller (COMM2) dropped. The manual says contact service only if it lasts more than a few hours. Internal and hardware faults need testing with the right instruments, so we treat them as a call.

The resistance between the solar array and earth on one input is below the inverter's test point (1200 kilohm by default). The manual says have an installer check the array for ground faults.

The grid voltage is out of range or not there at all. A tripped solar supply main switch, a blackout or a loose AC plug are the usual causes; the manual says have the AC plug and wiring checked if it persists.

The inverter's internal bus voltage went over its rating (Overvoltage DC) or a PV input drew too much current (DC Over current). The manual says have an installer verify the array and DC wiring, then contact service.

The voltage on string 1 or string 2 is above the inverter's limit. The manual says have an installer check the array voltage against the specification.

The residual current monitor's self-test is not working and the inverter is disabled. It is an internal fault; the manual says contact service.

The grid relay tested short (S/C) or open (O/C), so the inverter will not connect. The manual's only advice is to contact Schneider service, so treat it as an internal fault.

The inverter paused because it is too hot (OTP) or too cold (LTP) and resumes on its own when the temperature is back to normal. For heat, the manual says keep the back of the unit clear and out of direct sun. Heat shutdowns point at a failing fan, a blocked vent or a bad installation spot, so we treat them as a call.

A temperature sensor, the current sensor, an analogue input or the zero-crossing circuit inside the inverter has failed its check. All are internal faults the manual sends to Schneider service.

The display reads inverter offline with a DC voltage fault, or stays offline in good sun: the array voltage is missing or wrong. A DC breaker off, a blown DC fuse, a loose DC connection or a miswired string are the causes. A failed self-test means the inverter cannot prove its own protection works, so we treat it as a call.

Only the red light is on and the display reads ground fault: the inverter found a ground fault on the solar array and will not run until an electrician has found and fixed it and restarted the unit.

The display reads inverter offline with a ZC voltage fault: the inverter cannot see the mains. A tripped solar supply main switch or a loose AC connection are the usual causes.

No lights and a blank display in good sun means the AC and DC breakers are off, or the inverter has failed. The manual's fix is to turn the breakers on in the commissioning order.

The relay that connects the inverter to the grid has failed, so the unit will not feed in with sun and grid present. It is an internal fault on a brand with no Australian support.

Not a fault: the inverter is not getting enough power from the panels to run, which is normal at dawn, dusk and in heavy cloud. If it stays on through a sunny day, a string is open or the inverter's input has failed.

The inverter measured too little insulation between the solar array and earth, so it stopped. Water in a roof connector or a damaged cable is the usual cause; no Motech code list survives to give the exact wording.

The inverter has no power at all. On a sunny day that means the supply has been cut by a tripped switch or isolator, or the inverter's own power supply has failed.

Relay 2 with the Operation and Failure lights on and the screen cycling Idle means the grid relay inside the inverter has failed. One reboot is worth trying; if it comes back the unit has an internal fault and Motech is gone.

The settings memory has a problem (EEPROM Damaged), the unit was never set up at first start (Please initiate), or its self-test failed (Auto Test Failed). One restart is worth trying; a repeat needs a visit. A failed self-test means the inverter cannot prove its own protection works, so we treat it as a call.

The earth fault detector (GFCI Damaged), the output sensor (Sensor Damaged), the link between the two processors (SCI Damaged, Not Consistent), the internal DC bus (High Bus Voltage) or the reference voltage (2.5 V Ref Fault) has failed. All are internal faults, and the local repairers say any Inverter Fault on these means a new inverter.

The mains voltage (Grid V Fault) or frequency (Grid F Fault) is out of range, or the grid dropped out (Disconnect Grid), so the inverter disconnected. It reconnects by itself; daily repeats mean the grid voltage needs measuring.

The inverter is pushing too much direct current into the grid. One restart is worth trying; a repeat is the output stage drifting. DC on the AC side is a protection fault, so we treat it as a call.

Current is leaking to earth above the inverter's limit (GFCI active), so it stopped. The manual's step is to disconnect the DC and AC breakers and inspect the AC cables and breakers for damage.

The solar array voltage is above the inverter's range. It can show on a cold bright morning; if it keeps appearing the strings need checking.

The inverter got too hot and stopped. The manual's checks are the ambient temperature, the clearance around the unit and whether the cooling fins are blocked. Heat shutdowns point at a failing fan, a blocked vent or a bad installation spot, so we treat them as a call.

The insulation between the solar array and earth is too low, so the inverter stopped. Water in a roof connector or a damaged cable is the usual cause.

The relay that connects the inverter to the grid has failed. It is an internal fault, and KLNE's Australian company is in liquidation.

The inverter has no power at all. On a sunny day that means the supply has been cut by a tripped switch or isolator, or the inverter's own power supply has failed.

The right light is red: the inverter does not like its grid wiring, which the manual puts down to live and neutral swapped, the wrong grid type setting, or the earth not connected properly. It needs an electrician to check the wiring and connector.

The grid voltage is too high or too low (AC VOLTAGE) or the frequency is out of tolerance (GRID FREQUENCY), so the inverter disconnected. It reconnects by itself; the manual notes a long or thin AC cable can cause the voltage fault.

The inverter has no power at all. On a sunny day that means the supply has been cut by a tripped switch or isolator, or the inverter's own power supply has failed.

The relay that connects the inverter to the grid has failed, so the unit will not feed in with sun and grid present. The Bosch fault table shows this under INT ELECTRONICS rather than by name.

The bottom light is red: a communication fault with an accessory or the internet. FIRMWARE (top light red) means an update failed. Neither stops production; the manual says check the accessories and connection, or repeat the update.

All lights flashing red with DC ISOLATION means a short circuit or earth fault on the DC side. The Bosch manual says do not touch the unit, switch off the AC fuse and the DC breaker, and call for service.

All lights red means a DC overvoltage, an internal defect (SERVICE SWITCH) or faulty electronics (INT ELECTRONICS). The Bosch manual says do not touch the unit, switch off the AC fuse and the DC breaker, and call for service. Bosch left solar in 2016.

The left light is red: the array voltage is outside the inverter's range, which the manual puts down to the array being designed or wired wrongly. It needs an electrician to check the strings.

The top light is red: the temperature around the inverter is outside its limits. It restarts when it cools; the manual says check the installation conditions. Heat shutdowns point at a failing fan, a blocked vent or a bad installation spot, so we treat them as a call.

The two processors disagree (Consistent Fault), the memory, internal link, DC bus, reference voltage, DC sensor or earth fault detector has failed. The manual allows one disconnect and reconnect, then service if the message reappears.

The inverter is pushing too much direct current into the grid. The manual allows one disconnect and reconnect, then service if it reappears. DC on the AC side is a protection fault, so we treat it as a call.

The grid voltage or frequency is out of range (Grid Fault) or the inverter cannot see the mains at all (No Utility). The manual says wait five minutes; it restarts by itself when the grid is normal.

Current is leaking to earth above the inverter's limit, so it stopped. The manual says unplug the array and check the AC side around the inverter.

The inverter found an earth fault on the panels or a failed surge protector, so it stopped. The manual wants more than 8 megohms between the array and earth.

The manual's one line on a blank panel is to check the PV input connections. On a sunny day with the isolators on, the inverter's own power supply has failed.

The inside of the inverter is hotter than normal. The manual says lower the ambient temperature or move the inverter somewhere cooler, and call service if that does not help. Heat shutdowns point at a failing fan, a blocked vent or a bad installation spot, so we treat them as a call.

The array voltage is at or near the 500 V maximum. If it is below that and the fault stays, the manual says call service. Over-voltage, over-current and short-circuit faults can damage hardware, so we treat them as a call.

The relay between the inverter and the grid is not working. The manual's reset is to disconnect the array, wait for the screen to go off and reconnect; if the message returns, it is an internal fault.

Error: AFI means a residual current from an insulation error or ground fault in the solar system, and the inverter disconnected. On later NT firmware the same family shows as 102 Isolation, 103 AFI above 30 mA or 104 AFI above 0.3 A. The manual says the whole system must be checked for insulation errors.

The inverter reached its temperature limit and stopped feeding in; it restarts by itself once the heat sink cools. The manual blames the location, blocked air circulation or objects on the heat sink. Heat shutdowns point at a failing fan, a blocked vent or a bad installation spot, so we treat them as a call.

The grid voltage went outside 184 to 264 V (UAC_1 single phase, UAC_3 three phase), even briefly, so the inverter switched off. It restarts by itself once the voltage is back within limits.

The array's open-circuit voltage went above the inverter's maximum (750 V on the NT), so it stopped feeding in. The manual says check the array design and reduce the modules in series. Over-voltage, over-current and short-circuit faults can damage hardware, so we treat them as a call.

Later NT firmware shows 212 DC Quota (too much direct current in the output), 301 AFI-Over (the fault current sensor out of range), 302 Monitoring Error (the backup monitor disagrees) or a 9xx maintenance error. All are internal: one restart, then service if it repeats.

The inverter has no power at all. On a sunny day that means the supply has been cut by a tripped switch or isolator, or the inverter's own power supply has failed.

The grid relay that connects the inverter to the mains has failed, so the unit will not feed in with sun and grid present. The NT manual has no named relay message; it is an internal fault.