E56

Power Transistor Thermistor Faulty or Disconnected

Mitsubishi Electric · Mitsubishi FR-D700 Inverter

What does E56 mean?

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.

Additional Steps

Steps 1–2 are listed in Priority Fix.

  1. 3

    Ensure the thermistor is securely connected to the inverter PCB and properly seated for accurate temperature sensing.

Source: Mitsubishi FR-D700 Inverter
Open Manual (Page 5)