I have interfaced ADE7878 Energy IC to a microcontroller and I am trying to calculate kwh from it. As per the datasheet, on page 50 total active power of each phase can be read from the registers AWATTHR, BWATTHR, and CWATTHR. So, if this is the actual watthr value, then to get the kwh value, I just divide by 1000. But I believe the register values are not actual values (32 bit values) and I need to multiply by a conversion factor to get the actual kwh value. Can anyone please help with this ?

Note: I am using a 3 phase power supply at 60Hz frequency.

As per the datasheet(page 58), PMAX = 33,516,139 = 0x1FF6A6B, the instantaneous power computed when the ADC inputs are at full scale. So will dividing the value obtained from the register by Pmax give me the actual wh value ?