I am designing a 3-phase energy meter based on ADE7978 + 3x ADE7933. I have some questions that I can't solve and your help is needed :-)
1 Which terminal of the shunt is the one closer to household side : IPIN_A or IMIN_A ? (schematic from the ADE7978 manual, page 31 of 125)
(It is not clearly described. E.g. file www.analog.com/.../AN-1333.pdf
shows differently on page 3 and differently on page 5)
2 If my shunt has only 2 terminals (no gnd, size restrictions), can I merge GND_A with terminal that is closer to the grid?
3 If each ade7933 is going to measure voltage of its particular phase then I don't need the aux V2P pin. Can I remove all elements related to V2P pin and connect it directly to the VM? One pdf says so but I want to make sure.
4 For voltage measurement can I connect V1PIN_A direcly to the shunt, closer to grid side?
5 I can't find clear information where to connect the neutral line that goes into the meter? I know that the voltage measurement is done with a voltage divider at the V1P pin.
For example, the file https://www.analog.com/media/en/technical-documentation/application-notes/AN-1333.pdf (Page 2 of 13) shows some nonsense that neutral line = GND_MCU , which is not possible due to the principle of operation of the isolation barrier of the ade7933 :-)
Is the N connected to the 1k resistor? (This also doesn't seem possible to me because the GNDiso is connected to the phase voltage through GND_A)
Guy from this topic https://ez.analog.com/energy-metering/f/q-a/537715/ade7978-ade7933-measurements-always-return-the-same-value posted such a schematic, but no one corrected him.
Where to connect N?
6. When full documentation for the newer ADE7979 chip will be available? I would prefer to build something more future proof.
Thanks.
