Cause : DC Bus Undervoltage comes when the voltage level on the DC bus of the drive has fallen below the acceptable threshold.

1. One of the following conditions occurred while the drive was in operation:
• Voltage in the DC bus fell below the undervoltage detection level (L2-05).
• For 200 V class: approximately 190 V (160 V for single phase drives)
• For 400 V class: approximately 380 V (350 V when E1-01 is less than 400) The fault is output only if
L2-01 = 0 or L2-01 = 1 and the DC bus voltage is under L2-05 for longer than L2-02.

2. Input power phase loss

• The main circuit drive input power is wired incorrectly.
• Correct the wiring.

3. One of the drive input power wiring terminals is loose

• Ensure there are no loose terminals.
• Apply the tightening torque specified in this manual to fasten the terminals

4. There is a problem with the voltage from the drive input power

• Check the voltage.
• Correct the voltage to be within the range listed in drive input power specifications.
• If there is no problem with the power supply to the main circuit, check for problems with the main circuit magnetic contactor.