Every brand, by condition
Fault families
One page per condition, listing each brand's codes whose own wording names it: isolation, grid voltage, arc, over-temperature and the rest.
A family groups codes by the manufacturer's wording. It does not mean the codes share a cause, a trip setting or a fix: the same words can describe different measurements on different hardware, so work each code from its own entry and its manufacturer's document.
Families
- Isolation25 codes · 13 brandsWording that names low insulation resistance or an isolation fault between the PV array and earth.
- Grid voltage128 codes · 15 brandsWording that names grid or AC-side voltage outside the inverter's configured operating range.
- Grid frequency84 codes · 15 brandsWording that names grid frequency outside its range or changing too fast.
- Residual current18 codes · 12 brandsWording that names residual, leakage or ground-fault current.
- Arc15 codes · 9 brandsWording that names an arc fault, arc detection or the arc-fault circuit interrupter (AFCI).
- Over-temperature38 codes · 15 brandsWording that names an over-temperature, overheating or high-temperature condition.
- Meter, CT and comms23 codes · 9 brandsWording that names an energy meter, a current transformer (CT) or an external communication link.
- BMS16 codes · 5 brandsWording that names the battery management system (BMS) or the battery's communication with the inverter.
- DC over-voltage20 codes · 10 brandsWording that names PV or DC input voltage above the inverter's input range.
- Relay and self-test34 codes · 10 brandsWording that names an output relay, or a self-test or self-check the inverter runs on its own protection.
How codes are placed
- Only the manufacturer's own title and description are read, never Wattbench's fixes or search keywords.
- Each family has a published list of evidence terms, matched as whole words. The title decides first; the description decides only when the title names no family.
- A code that names a test of a protective function (an AFCI self-test, an RCD test) sits with relay and self-test, not with the function.
- Anything that matches no family, or more than one, stays unclassified: 614 of 1015 codes today. They are still in their brand library and in the Fault Code Finder.