Motor stall

What does 7121 mean?

The drive has tripped due to a motor stall condition. This fault is triggered when the motor current exceeds the stall current limit, and the output frequency or speed is below its set limit for a configured time. This indicates a severe overload or mechanical blockage, which can cause significant motor or drive damage if persistent.

• Severe mechanical overload or complete seizure of the driven machinery (e.g., pump impeller jammed, mixer blades stuck).
• Gross misconfiguration of motor stall protection parameters (e.g., P30.01 Motor stall current set too low, P30.02 Stall time set critically short).
• Motor attempting to start into a locked rotor condition due to a faulty brake or mechanical lock.
• Significantly undersized motor for the application, unable to deliver required starting or running torque.
• Broken shaft or coupling between motor and load causing the motor to spin freely while the load remains stalled.

Click steps to track your progress.

1. 1

   De-energize the system. Manually attempt to rotate the driven equipment shaft; identify and clear any mechanical jams or binding.

2. 2

   Verify drive parameters P30.01 (Motor stall current limit) and P30.02 (Motor stall time) are correctly configured for the motor and application.

3. 3

   Confirm motor nameplate data (e.g., nominal current, nominal speed) is accurately entered into drive parameters (e.g., P99.04, P99.05).

4. 4

   Measure the motor current (e.g., using a clamp meter on a single phase) during an attempted start, comparing to motor nominal and stall current.

5. 5

   Check for signs of motor overheating (e.g., smell, hot casing) indicating sustained high current due to overload.