When setting the output voltage as 60 V (because the max power of the IT6720 is 100 W) the max output current is/ will be 100 W/60 V = 1.6 A. When changing the output voltage to 30 V, the output current will be 100 W/30 V = 3.2 A. Calculate accordingly when the output voltage is 20 V, the output current should be 5 A, but as the max current rating of IT6720 is 8 A, then the final max output current will be 5A.