MOTOR STALL

What does 7121 mean?

The motor is operating in a stall region, indicating an excessive mechanical load or insufficient motor power for the applied task. Sustained stalling leads to rapid motor overheating, potential winding damage, and reduced motor lifespan.

• Mechanical jamming or excessive friction in the driven equipment, preventing the motor from rotating freely.
• Motor size is insufficient for the continuous torque demand of the application, leading to operation below rated speed.
• Incorrect drive acceleration/deceleration ramps (e.g., P2-01, P2-02) causing the motor to stall during starting or stopping.
• Loss of motor speed feedback (e.g., encoder fault) in vector control modes, causing the drive to miscalculate motor speed and torque.
• Parameter P2-07 (Stall protection threshold) set too low, triggering the fault prematurely under normal operating conditions.

Click steps to track your progress.

1. 1

   1. Disconnect the motor from the mechanical load and attempt to rotate the motor shaft by hand, checking for any binding or resistance.

2. 2

   2. Measure the motor current (P1-15) during operation and compare it against the motor's rated current (from nameplate) under various load conditions.

3. 3

   3. Adjust drive acceleration (P2-01) and deceleration (P2-02) ramp times to be longer, allowing the motor more time to reach speed.

4. 4

   4. Verify the motor's nameplate data (e.g., rated power, current, speed) are correctly entered into drive parameters (e.g., P1-01 to P1-04).

5. 5

   5. Inspect the driven machinery for blockages, worn bearings, or excessive friction using visual inspection and manual manipulation.