AnsweredAssumed Answered

ADE7880 Current Transformer Interface

Question asked by vignesh on Sep 12, 2012
Latest reply on Sep 18, 2012 by hmani

Hi Everyone. I'm trying to build a 3-phase energy meter based on the ADE 7880 & Arduino. I bought a 50A/5A current transformer. How do I calculate the burden resistor for the CT interface ?

 

I found this equation in the ADE7880 eval board user manual :

 

R1 = R2 = 1/2 × 0.5/√2 × N/IFS

 

However I'm not sure if the N is the turns ratio or the CT current ratio which in this case is 10. The turns ratio is not specified in the CT name plate.

If I use the N as 10 & Ifs as 5A (secondary full scale), I get a value of 0.35ohms. Is this correct ? or am I missing something? Also please let me know if the burden resistor can be a quarter watt component.

 

I'm looking forward to your suggestions. Thanks.

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