Overcurrent

What does F01 mean?

The inverter has detected that the output current exceeded 185% of the rated output current for more than 60 milliseconds. This indicates a significant overload on the motor or a short circuit in the output wiring. This will cause an immediate switch-off of the inverter to prevent damage to the motor or the drive.

• Direct short circuit between two output phases (U, V, W) or between an output phase and ground.
• Sudden, heavy mechanical shock load on the motor (e.g., jammed conveyor, sudden braking) causing instantaneous current spike.
• Motor winding insulation breakdown, creating an internal short circuit within the motor.
• Output cable insulation breakdown (e.g., due to aging, mechanical damage) causing a phase-to-phase or phase-to-ground fault.
• Inverter output stage (IGBTs) failure, leading to uncontrolled current flow.

Click steps to track your progress.

1. 1

   Immediately disconnect the motor from the inverter output terminals (U, V, W).

2. 2

   With the motor disconnected, measure insulation resistance of the motor windings to ground (e.g., 500VDC megohmmeter, expected >100M Ohm).

3. 3

   Measure the resistance between each output phase (U-V, V-W, W-U) of the motor with a multimeter to detect a short circuit (expected typically <1 Ohm but balanced).

4. 4

   Inspect the motor cables and connections (terminals, junction boxes) for signs of damage, chafing, or arcing that could indicate a short.

5. 5

   Power up the inverter with the motor disconnected and attempt a test run without a load; if the F01 persists, the inverter's output stage is likely faulty.