ABB sold its solar inverter division to Fimer in 2020, which affects how support and replacement parts are sourced today. If you own an ABB-branded UNO-DM, TRIO, or legacy PVI-series inverter, here’s what common fault codes mean and what your service options look like now that the platform has changed hands.
Common ABB / Fimer Error Codes
Arc Fault Detected (varies by model, often flagged as a dedicated LED pattern): A safety fault requiring prompt attention. See our guide on arc fault errors for what this means.
Ground/Insulation Fault: Reported as a specific fault code on the display — indicates reduced insulation resistance in the DC wiring, often from moisture or connector degradation.
Grid Fault Codes: The inverter has detected grid voltage or frequency outside its operating range. Usually transient; frequent recurrence warrants inspection.
Internal Fault / Fan Fault: A broad hardware category, common on units 8+ years old, often related to internal cooling or power components.
No Display, No Output: A full hardware failure — common on older UNO-DM and PVI-series units where components are aging out.
Why the ABB-to-Fimer Transition Matters for Repairs
Because ABB’s solar business was acquired by Fimer, replacement parts and warranty support for ABB-branded units now route through Fimer’s channels — and availability has narrowed over time. For many older ABB units, sourcing an exact replacement part is no longer practical, which shifts the repair-vs-replace decision toward full inverter replacement sooner than it would for an actively-supported platform.
Repair or Replace?
If your ABB or Fimer inverter is still within its original warranty window, replacement is typically covered — documentation from a licensed technician is required. Outside of warranty, and especially for units on the older PVI platform, full replacement is usually the more practical and cost-effective path given parts availability.
Related Reading
- Inverter Errors & Failures: Complete Troubleshooting Guide
- Solar Arc Fault Errors: Causes, Risks & What to Do
- Your String Inverter Is Failing: Repair, Replace, or Upgrade?
- Help for Orphaned Solar Systems
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