Motor underload

What does 17 mean?

The motor underload protection has tripped, indicating that the motor is operating with insufficient mechanical load or no load at all. This can be caused by a broken belt, pump cavitation, an uncoupled shaft, or a process anomaly. Operating in an underload condition can sometimes lead to drive instability or signify a mechanical issue that requires attention.

• Mechanical load disconnection (e.g., broken belt, coupling failure, pump impeller damage) causing motor current to drop below parameter P2-22 (Underload current limit).
• Process fluid loss or cavitation in pump applications, reducing required torque and current draw below setpoint P2-22.
• Incorrectly configured motor underload threshold (Parameter P2-22) or delay time (Parameter P2-23) for the actual process load conditions.
• Motor shaft or driven equipment blockage (e.g., jammed valve) preventing proper load engagement or causing a sudden reduction in load.

Click steps to track your progress.

1. 1

   Inspect mechanical coupling between motor and driven equipment for damage or disconnection.

2. 2

   Verify the process load (e.g., fluid level in pump, material flow on conveyor) corresponds to normal operating conditions.

3. 3

   Measure motor output current (terminals U, V, W or display parameter P0-01) and compare against motor nameplate full load current and underload trip threshold (P2-22).

4. 4

   Review and adjust Parameter P2-22 (Underload current limit) and Parameter P2-23 (Underload delay time) to match actual process characteristics, if motor current is consistently below P2-22.

5. 5

   Perform a controlled start-up and monitor motor current via P0-01 to confirm proper load engagement and current draw.