Inverter fault codes: what they mean and what to measure
Type the code on your inverter's display or pick it from the list. See what it means, which section inside the unit it concerns and what to check first. Codes a user can fix are marked separately from those needing service.
Pick a code above or type the one on your display; its meaning, place on the diagram and what to measure open here.
Source: the user manual of Voltronic/Axpert-based 1–5 kVA units. Must and other brands built on this base use the same codes; still, compare with your unit's manual. Codes 51–58 exist on 4–5 kVA models.
⚠ Steps that need the cover off are dangerous: the DC bus stays at ≈400 V and the battery can deliver hundreds of amps. If you're not sure, leave these steps to a repairer.