R-Pro › Field cases › Air conditioning
AC Inverter Trip — Current / Temperature Protection
Likely causes
Check IPM module, compressor, DC bus voltage
Check: DC bus voltage = normal 280–380V (220V single-phase input). IPM module = U/V/W output balance (3-phase imbalance <5%). Compressor coil resistance = 3-phase balanced (deviation <5%). Insulation megger ≥1 MΩ. Thermal protection = trip when IPM heatsink >70°C (typical).
What to do: Work with system OFF. Wait 1 min for DC bus capacitor to discharge. IPM short = replace entire PCB (IPM not sold separately). Compressor insulation <1 MΩ = replace compressor. Heatsink >70°C = check fan motor/ventilation. After repair, run 30-min test and verify no re-trip.
Repeated inverter trips = likely IPM or compressor fault. Replace parts after diagnosis. IPM is not separately available — replace whole PCB. Inverter compressor = NOT interchangeable with non-inverter. Expensive repair.
All 565 cases work offline in R-Pro, with error codes for 62 brands and P-T data for 108 refrigerants.
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