How to solve Err09: Undervoltage?

Panel display

Common causes of failure

Single-phase 220V inverter detects DC bus voltage lower than 210V, three-phase 380V inverter detects DC bus voltage lower than 350V, undervoltage fault.

• Abnormal input voltage, open or contactor abnormality；
• The existence of high-power equipment in the power grid in the startup or operation of the power grid voltage pull down；
• In the process of frequency converter operation in the power grid has a transient dropout；
• Inverter voltage detection circuit failure and internal relay failure.

Solution

1. Peripheral circuit problem troubleshooting:

• The model of the inverter does not match the grid voltage, before purchasing the inverter to confirm that the grid voltage is 220V or 380V, and the input voltage specifications of the inverter whether or not it matches.
• Abnormal grid voltage input, low voltage. Use the multimeter AC voltage file to measure the R, S, T input voltage of the inverter terminals is within the normal operating range, the input specification is 220V or 380V, the voltage fluctuation range of normal operation is +15%. You can check whether it is due to abnormal damage to the circuit breaker in the front end of the inverter, you need to use a multimeter to measure the voltage of the upper and lower ports of the circuit breaker respectively, to determine whether the voltage is abnormal due to damage to the circuit breaker, replace the circuit breaker.
   

• In the same grid with inverter, at the same time connected to other large loads, high-power loads in the start-up operation of the grid voltage down, then you can fine-tune the parameters FA.18, if the parameters of the inverter is still not normal operation, then you need to add a voltage regulator in the input side of the inverter, or replace the high-capacity transformer.
• d. In normal operation of the power grid instantaneous power failure caused by the inverter reported undervoltage fault, then you can press the reset button on the inverter keyboard and then restart, or modify the parameters FA.22 instantaneous stop non-stop function.

2. Inverter failure problems:

• The voltage detection circuit is damaged, if the difference between the DC bus voltage display value and the actual measured bus voltage value by pressing the keyboard shift key is too large, please contact us.
• Without load start normal, plus load motor acceleration in the operation of the report Err09, generally damaged for the inverter internal DC contactor problems caused by contact us to replace the contactor.