FET1 Over Temperature Shutdown

What does F57 mean?

This Automatic Fault occurs when the internal temperature of FET1 exceeds 105 °C, triggering a shutdown to protect the inverter's power components. The fault clears automatically when the temperature drops to 75 °C.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Let inverter cool down and try restarting if ambient temperature is high.

2. 4

   Hold a piece of paper to inverter vents to check the fan; if failed, have inverter serviced.

3. 5

   Increase clearance around the inverter or unclog the fan air intake.