Code Uv1: DC Bus Undervoltage

Code type: Fault Manual section: Yaskawa A1000 Troubleshooting Input power phase loss. - The main circuit drive input power is wired incorrectly. - Correct the wiring. 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. Refer to Wire Gauges and Tightening Torque on page 76 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. The power has been interrupted. Correct the drive input power. The main circuit capacitors are worn. - Check the maintenance time for the capacitors (U4-05). - Replace either the control board or the entire drive if U4-05 exceeds 90%. For instructions on replacing the control board, contact Yaskawa or your nearest sales representative. The relay or contactor on the soft-charge bypass circuit is damaged. - Cycle power to the drive and see if the fault reoccurs. - If the problem continues, replace either the control board or the entire drive. For instructions on replacing the control board, contact Yaskawa or your nearest sales representative. - Check monitor U4-06 for the performance life of the soft-charge bypass. - Replace either the control board or the entire drive if U4-06 exceeds 90%. For instructions on replacing the control board, contact Yaskawa or your nearest sales representative.