Excessive Speed Deviation

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This fault is triggered when the motor speed deviates excessively from the commanded speed, exceeding a set threshold (P027), often in applications with encoder feedback. This indicates a loss of control, where the motor is either running too fast or too slow relative to the commanded reference, causing an inverter trip to prevent instability.

• Mechanical overload on the motor shaft exceeding its rated torque, causing the motor to slip or stall.
• Loss of motor phase due to open circuit in motor wiring or failure of an inverter output switching component (e.g., IGBT).
• Incorrect tuning of PID speed loop parameters (e.g., P-gain P023, I-gain P024) leading to instability or slow response.
• Motor braking mechanism (e.g., mechanical brake, friction) is incorrectly engaged or malfunctioning, impeding motor rotation.
• Encoder feedback signal intermittent or noisy, causing the drive to misinterpret actual motor speed and overcompensate.

Klikk på steg for å spore fremgangen.

1. 1

   Inspect the mechanical load connected to the motor shaft for any binding, obstructions, or excessive friction. Disconnect the load and test the motor independently if possible.

2. 2

   With power off, use a multimeter to measure the resistance between motor terminals U-V, V-W, and W-U. All three measurements should be balanced and within specified motor winding resistance.

3. 3

   Monitor the motor's actual speed (e.g., F001, F002) and commanded speed (e.g., F003) via the drive's display or monitoring software during operation. Compare the values to identify the magnitude of deviation.

4. 4

   Verify the set value for parameter P027 (Speed Deviation Limit) is appropriate for the application. Consider increasing it slightly or adjusting PID gains (P023, P024, P025) if transient deviations are triggering the fault.

5. 5

   Check for consistent and stable encoder feedback by monitoring the raw encoder counts or speed feedback value (e.g., P2-02) to detect intermittency or noise.

6. 6

   Ensure the motor's nominal speed (P003) and rated current (P004) are correctly configured in the drive parameters to match the motor nameplate.