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.

• Restricted airflow around the inverter's cooling fins or fan intake/exhaust vents due to dust accumulation or obstruction.
• Malfunctioning cooling fan (e.g., seized motor, broken blades, low RPM) not effectively dissipating heat from the FET1 heatsink.
• Sustained operation at or above the inverter's rated continuous power output, leading to excessive heat generation.
• Degraded thermal paste or inadequate contact between FET1 package and its heatsink.
• Internal fault within FET1 or its associated gate drive circuit causing increased conduction losses.

Click steps to track your progress.

1. 1

   1. Power down the inverter, disconnect AC and DC sources, and allow components to cool (e.g., 30 minutes).

2. 2

   2. Inspect all cooling fan(s) for proper operation, verify fan rotation, and clean any dust buildup from fan blades and heatsink fins using compressed air.

3. 3

   3. Measure the ambient temperature around the inverter and ensure it is within the manufacturer's specified operating range (e.g., -20°C to +45°C).

4. 4

   4. Verify that the load connected to the inverter's AC output does not exceed its continuous power rating (e.g., check output current via display or clamp meter).

5. 5

   5. Check for loose mounting screws or improper seating of FET1 to its heatsink, ensuring adequate thermal transfer.