NMAX (Maximum system speed exceeded)

What does x200 mean?

The maximum system speed (defined by C0596) has been exceeded. This typically occurs due to an excessively high active load, such as in hoist applications, or if the drive is not speed-controlled and torque limits are too low, allowing overspeed.

• Excessive regenerative load torque exceeding the drive's braking capacity (e.g., during rapid deceleration in hoist applications).
• Incorrectly configured speed control loop parameters (e.g., P1-07, P1-08) leading to overshoots that exceed the maximum speed setpoint.
• Parameter C0596 (Maximum Speed Limit) set too low for the application's required operating range, causing premature tripping.
• Mechanical load decoupling or failure (e.g., a broken gearbox shaft) allowing the motor to overspeed without resistance.
• External speed reference signal (analog input P1-01) momentarily spiking above expected values due to noise or controller malfunction.

Click steps to track your progress.

1. 1

   1. Verify parameter C0596 (Maximum Speed Limit) setting against application requirements and motor datasheet, adjusting if necessary.

2. 2

   2. Monitor motor speed (P0-03) and DC bus voltage (P0-01) during operation to identify peak values and system behavior.

3. 3

   3. Inspect mechanical load for freedom of movement or disconnection, especially in hoist or vertical applications.

4. 4

   4. Review and tune speed controller parameters (e.g., P1-07, P1-08) to improve transient response and reduce speed overshoots.

5. 5

   5. Check the external speed reference signal at terminal AI1 for stability and accuracy using a multimeter (voltage or current).

6. 6

   6. Evaluate braking resistor health and sizing if the application involves significant regenerative loads (e.g., measure resistance across resistor terminals).