Hi fiends,

So far i am able to calculate voltage, currents, frequency.

also i worked on Watt/VA gain, RMS and Offset calibration.

now when i am freezing out my design and components.

i am confused with very stupid things.

my requirement is to design 1-PH energy meter using ADE7763.

with Meter constant = 3.2 IMP/Wh.

nominal voltage = 220 , max voltage = 240 V

base/ref/tested current = 5 A, Imax = 15A. (CT specs = 2500:1, IP Arms = 0.25 to 20, Rb=30 Ohms, DCR=105-135, electrohms CT1232).

F= 50Hz.

while going through calibration process, i have read in ADE7763 datasheet, page 35, equation 39

*"the line voltage and maximum current scale half of their respective analog input ranges. The line voltage and maximum current should not be fixed at the maximum analog inputs to account for occurrences such as spikes on the line" . *

to satisfy this condition what could be then my burden resisters across CT and for Voltage divider resisters.

currently I am using 2Rb = 4.4 Ohms

and Voltage divider = 255K + 255K in series with 1K in parallel.

thanks.

Regards,

Umesh

Hi Umesh

For ADE7763 default setting, 0.5V is Full scale value. So, the recommendation is that : during calibration, keep the current and voltage levels at the input of the IC, for a PGA gain of 1, to be 0.25V. It does not mean that you cannot operate at a current or voltage up to Full-scale at any point of time. This step is only for calibration purpose.

Your current scaling seems right, but I would add further attenuation to the voltage lines. I hope this cleared your confusion. If you still have doubts on the scaling, please revert back.

Regards

hmani