The Complete Guide To Solis Inverter Error Codes

The grid frequency is jumping around and the inverter is waiting for it to steady. It reconnects by itself.

The inverter measured too much resistance in the AC path to the grid, usually an undersized or long cable run to the switchboard or a poor connection. A one-off can clear itself, but if it keeps coming back the cabling needs an electrician.

On a three-phase inverter, the voltages on the three phases are too far apart, or one phase is wired wrong or undersized. The inverter waits until the phases are balanced again.

The inverter is seeing a rough or distorted mains waveform, often where several inverters share one line or there is noisy equipment nearby. The manual also lists internal damage as a cause, so if a restart does not clear it the inverter needs testing. Internal and hardware faults need testing with the right instruments, so we treat them as a call.

The circuit that measures the inverter's output current is giving bad readings. If a restart does not clear it the sensing circuit has failed.

The inverter's control circuit lost track of the grid current it was trying to match. If a restart does not clear it, the power board has a fault.

The inverter cannot see mains power on its AC side. Either the power is out, the solar supply main switch or breaker is off, or an AC connection has failed.

The grid frequency went above the inverter's limit for a moment and it disconnected. It reconnects by itself once the grid is steady again.

The mains voltage at the inverter went above the limit it is allowed to export at, so it disconnected to protect itself. It usually clears on its own when the grid settles; if it happens most sunny afternoons the cable run or the street voltage needs checking.

On a three-phase inverter, the phases are not 120 degrees apart, which usually means the AC wiring is in the wrong order or a phase is missing. It needs an electrician to check the AC connection.

The grid frequency dipped below the inverter's limit and it disconnected. It reconnects by itself once the grid is steady again.

The mains voltage dropped below the inverter's lower limit, so it stopped exporting. This is almost always the grid or a brownout and clears by itself.

The current from the panels is not what the inverter expects, which usually means a damaged or loose DC connection. The DC wiring and connectors need checking by an electrician.

The voltage coming from the panels is above what the inverter can accept, which happens when too many panels are in one string, especially on cold clear mornings. The string design needs checking by an electrician.

On a Solis hybrid, the appliances on the backup circuit are drawing more than the inverter can supply off the battery. Reduce what is on the backup circuit and restart.

A string from the panels is connected the wrong way round at the inverter. This is a wiring fault and must be corrected by an electrician.

The arc-fault detection module inside the inverter failed its own test. If a restart does not clear it the module has failed and needs a technician.

The inverter detected electrical arcing in the panel wiring, which is a fire risk. Leave the system off and have an electrician find the loose or damaged connection.

The inverter's leakage-current sensor failed its own test at start-up. If a restart does not clear it the sensor or board inside has failed.

The inverter measured current leaking to earth from the solar wiring, usually damaged cable insulation, water in a connector, or a wiring problem on the AC side. Wet-morning alarms can be ageing panels, but any repeat needs an electrician because this is an electrical safety trip.

The inverter found a low resistance between the active and the earth on the AC side, which means a wiring or earth fault in the AC circuit. It needs an electrician.

The inverter found too little insulation between the panel wiring and earth, usually water in a connector or isolator, a chafed cable or a damaged panel. Morning or wet-weather alarms that clear by midday point to moisture; a persistent one is a safety issue and needs an electrician.

The inverter found a low-insulation or earthed point part way along a panel string, often a wet connector or a damaged panel. Like any insulation fault, it needs testing by an electrician.

The inverter's internal temperature went over its limit, so it cut back or stopped. Usually it is mounted in direct sun or a hot, closed space; it comes back once it cools, but if it happens on ordinary days the fan or heatsink needs a look. Heat shutdowns point at a failing fan, a blocked vent or a bad installation spot, so we treat them as a call.

The inverter is below its minimum operating temperature and is waiting to warm up. It clears itself once the day warms.

The small power supply that runs the inverter's own electronics has failed. If a restart does not clear it the inverter needs repair.

The circuit that lifts the panel voltage inside the inverter has failed its check. If a restart does not clear it, the inverter has an internal hardware fault.

The inverter is letting a small amount of DC into its AC output, which the grid rules do not allow. A one-off can clear with a restart; if it keeps coming back the output stage needs testing. DC on the AC side is a protection fault, so we treat it as a call.

The inverter's two control processors have stopped talking to each other, or the control software is missing or does not match the hardware. If a restart does not clear it the control board has failed.

The main switching transistors inside the inverter saw too much current. If a restart does not clear it the power board has failed.

The inverter's control processors did not agree with each other when it started up. If it stays stuck here after a restart the control board has a fault.

The voltage on the inverter's internal DC bus went too high. It can follow a string that is too long, but it is often a fault inside the inverter and needs testing.

The inverter pushed more current into the grid than it is allowed to, often because the grid waveform is distorted or an AC connection is poor. A one-off clears itself; repeated alarms need a look at the AC side. Over-voltage, over-current and short-circuit faults can damage hardware, so we treat them as a call.

The relay that connects the inverter to the grid failed its self-test. Solis says to check the AC wiring and earthing first, but a repeat usually means the relay or power board has failed, which is a job for an electrician.

The voltage on the inverter's internal DC bus is too low. The manual puts it down to internal damage or a wire that has come loose, so it needs the inverter opened and tested.

The two halves of the inverter's internal DC bus are not sitting at the same voltage, which points to a failing component inside. It needs the inverter tested by an electrician.

The inverter has lost contact with the export-limit meter or EPM device, so it stops or limits output to be safe. The meter cable or setting needs checking.

On a Solis hybrid, the inverter has lost contact with the battery or the battery is reporting an alarm. The battery cable, settings or the battery itself need checking.

On a Solis hybrid, the inverter cannot see the battery. Usually the battery breaker or fuse has tripped or the battery is switched off.

On a Solis hybrid, the battery voltage is higher or lower than the inverter expects. A restart may clear it, otherwise the battery and its settings need checking.