Modified on Tue, 10 Nov 2020 at 10:30 AM

UNB-BUS happens when voltage of DC BUS is not equal to two times of the voltage of DC half-BUS . 

When it happens, just following steps below to do the trouble shooting:

1.    Please restart the inverter . If this happens again, please move to the next step;

       if the inverter back to normal, then case is over;

2.    If this happens to a newly installed inverter, please recheck voltages of all the DC input strings . If they are higher than the required value in the data sheet, please remove some PV panels and try again.

3.    If this happens to a normally working inverter that has been working for days or months or years, please contact after-sales people of Ginlong.

4    Use a multi-meter to check the voltages between PV+ and earth, PV- and earth of all of the PV strings. (it should be decreasing from a certain value between 5% of Voc and 95% of Voc);

If the voltage value shown on the multi-meter is constant, than there must be something wrong in this PV strings.

5     Please check the value of V_BUS and H_V_BUS in Running messages of Advanced info in the LCD of the inverter.

      At the same time , you need to send all the data that you have got to Ginlong,  and the model as well as its serial number too, thanks.

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