Technical Support

Hi I am struggling to get setup. my 8Kw inverter is set up as a backup system using grid, solar, and genset, I have 500 Ah of batter. Other than continuously going into F18 fault mode even on the smallest of loads it also has a habit of not using solar to charge the batteries if the grid power is off. Where I live we only have grid power for 8hrs a day and this usually at night so this problem basically renders my inverter useless. What could the problem be?