Overspeed Error

What does E81. mean?

An overspeed error occurs when the motor's rotation speed, as detected by the encoder, exceeds the configured 'Overspeed Error Detection Level' (P026) multiplied by the maximum frequency. This can be caused by an incorrect P026 setting, improper encoder wiring, or actual runaway motor conditions. The inverter trips to prevent mechanical damage or unsafe operation.

• Inverter's output frequency is too high due to incorrect speed command (e.g., analog input signal 0-10VDC or 4-20mA is saturated).
• Incorrect P026 (Overspeed Error Detection Level) parameter setting, set too close to the maximum operating speed.
• Encoder feedback error, causing the inverter to misinterpret motor speed as higher than actual (e.g., noisy encoder signal).
• Motor runaway condition due to a mechanical fault or loss of load, combined with insufficient braking.
• Incorrect P004 (Maximum Output Frequency) or P003 (Rated Motor Frequency) settings, causing a miscalculation of the overspeed threshold.

Click steps to track your progress.

1. 1

   1. Monitor the inverter's actual output frequency (e.g., through display parameter d001) and the speed command source (e.g., analog input voltage).

2. 2

   2. Review and adjust parameter P026 (Overspeed Error Detection Level) to ensure it provides a safe margin above maximum operating speed.

3. 3

   3. Use an oscilloscope to check the encoder A/B phase signals for noise or intermittent drops that could cause erroneous speed readings.

4. 4

   4. Check the motor and driven machinery for any mechanical issues that could cause sudden speed increases (e.g., broken coupling, loss of load).

5. 5

   5. Verify parameters P003 (Rated Motor Frequency) and P004 (Maximum Output Frequency) match the motor and application specifications.

6. 6

   6. Temporarily reduce the maximum speed command source or maximum frequency (P004) to test if the overspeed threshold is still triggered.