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ADE7878 Current measurement

Question asked by sathis on May 26, 2014
Latest reply on Jun 4, 2014 by dlath

Dear All,

 

I am using ADE7878 for 3Phase Energy meter purpose. I have calibrated 3voltage channels. Now, i need to calibrate current channels.

 

Actually I am using 400/1A Current transformer. 1A CT output is given to the 0.3 Ohm resistor to get 0.3V(rms) output. This 0.3V is given to ADE7878 Current channel ADC inputs through filter circuits.

If I calculate the Gain using the formula given in AP1076, Gain register value is exceeding the register value.

I am taking the RMSref value as 4000000.(400A)

RMSref/RMS = 400000/3785635 = 1.056626

Gain = 1.056626-1=0.056626

Gain in Hex = 1073F85 (Decimal - 17252229)

The above value is exceeding the xIGAIN register value.

Please tel me how to solve this.

 

Waiting for your reply.

 

Regards,

Sathis

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