Hi

How can i tell the ADE7880 the CT ratio and voltage reduction ratio so it correctly measure current volt and power?

regards

Hi

How can i tell the ADE7880 the CT ratio and voltage reduction ratio so it correctly measure current volt and power?

regards

Hi Hmani

I red the an-1171 its a good note but i have 3 questions regarding the 4 equation at the beginning of page 11 in an-1171

q1- what is the VRMS[LSB] and IRMS[LSB] mentioned in two eqations

V constant [V/LSB] = Voltage Input [V]

VRMS[LSB]

I constant [Amps/LSB] = Current Input [A]

IRMS[LSB]

q2 - registers xVGAIN and xIGAIN are they only used to register the channel gain or the contents are used by the ADE7880 to make power calculations ?

q3 - Voltage input is it the 220v ac or the 0.219780v ac from the voltage divider witch is 1Mohm and 1Kohm also Current input is it the 10amps that are consumed by the load or 0.005amps the output of the current transformer with the CTratio of 2000:1?

best regards

Hi gamaleee

1. VRMS[LSB] and IRMS[LSB] are readings read out of VRMS and IRMS registers, respectively.

2. xVGAIN and xIGAIN will affect power calculations as well, as they are always included in the datapath.

3.The voltage and current inputs that must be used in the equations are 220V and 10A.

Regards

hmani

Hi gamaleee

During your calibration process, use the correct CT turns ratio, burden resistor value and attenuation factor to get an accurate representation of the real-world quantities like power and energy from the corresponding register readings. This app note explains the calibration process: http://www.analog.com/static/imported-files/application_notes/AN-1171.pdf

Regards

hmani