Under-voltage Error

What does E09 mean?

This fault occurs when the DC bus voltage inside the inverter drops below a critical threshold, indicating a control circuit fault or an unstable input power supply. This condition can also generate excessive motor heat or cause low torque, leading to an inverter trip to protect the system.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Ensure the power supply capacity is adequate for the inverter and motor load requirements.

2. 4

   If the power supply is known to be unstable, consider installing an input AC reactor to smooth line fluctuations.

3. 5

   Verify AVR settings (A081, A082) and ensure they are not inadvertently causing undervoltage conditions.