PV fault

Inverter IGBT overtemperature

Power-stage overheating from cooling failure or a blocked heat sink.

Quick answer

IGBT overtemperature is when the inverter’s power-switching stage runs too hot, usually from a failed cooling fan, a clogged heat sink, or high ambient. It forces the inverter to derate (clip) or trip (e.g. Huawei SUN2000 code 6001) and shortens IGBT and DC-link capacitor life.

Symptoms

  • Midday derating/clipping that tracks heat-sink temperature.
  • Thermal trips on the hottest days or hottest inverters in the row.
  • Audible or measured fan fault preceding the temperature rise.

SCADA signatures

  • Heat-sink/IGBT temperature climbing toward the OEM limit (<60 °C ambient spec).
  • Power derate that correlates with temperature, not irradiance.
  • Hardware fault code on a single inverter — e.g. Huawei 6001 IGBT overtemp / 6011 fan abnormal.

Root cause

Cooling-fan bearing wear or dust ingress, a heat sink blocked by debris, or sustained operation above the ambient spec. Each thermal cycle also ages the DC-link capacitors, so the fault compounds other inverter failure modes.

Financial impact

Thermal derating silently clips peak-hour energy, and repeated overtemperature events cut years off the inverter’s service life. A €200 fan replaced on schedule prevents a five-figure power-stage failure.

How NuraVolt detects it

NuraVolt trends per-inverter thermal behaviour and attributes temperature-correlated derating to cooling rather than design clipping. Its RUL layer projects days-to-fault from the temperature trend so the fan is replaced on a planned visit, not after a trip.

Methodology & sources: FAULT_DETECTION_TECHNICAL_SPEC.md · nuravolt/fault/rul_models.py · public/data/manuals/seed/synthetic/huawei-sun2000-fault-codes.md

Frequently asked questions

See also

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