Mitsubishi Electric · FR-D700 Inverter
The power transistor thermistor is faulty or disconnected (specific to FDCVA151-251 models), impacting temperature monitoring of the power transistors. This can lead to inverter damage from overheating.
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Inspect the power transistor thermistor connection for dislodgement or damage, particularly on FDCVA151-251 models.
Measure the resistance of the thermistor to verify functionality and compare to the specified temperature-resistance chart.
Ensure the thermistor is securely connected to the inverter PCB and properly seated for accurate temperature sensing.