Calibration Command

The calibration command (CAL) is used to automatically calibrate the board. It requires accurate and stable voltage and current sources and loads, which can be provided by a meter test bench, such as the WECO (or equivalent equipment). Refer to the Calibrate the Demo Board Using the Demo Meter Application for additional information.

The calibration command can receive the following parameters, depending on which measurements are to be calibrated:

Ua , Ub , Uc: Rms voltage applied to the voltage input. Units: Volts.
Ia , Ib , Ic , In: Rms current applied to the current input. Units: Amps.
Aa , Ab , Ac , An: Angle between the voltage and current vectors. Units: Degrees. The value is positive if the current is lagging the voltage.
Vd: Rms voltage applied to the voltage input in case this special “D” channel is used. Units: Volts.
AVAB, AVAC: Angle between the voltage vectors in phases A-B and A-C. Units: Degrees.

The maximum resolution available is 0.001V (voltages), 0.0001A (currents) and 0.001º (angles).

Examples:

Calibrate phase A, applying 220.00V, 5.000A, angle = 60.00º: “CAL (Ua = 220.00, Ia = 5.000, Aa = 60.00)”.
Calibrate phase B, applying 230.00V, 10.000A, angle = 60.00º: “CAL (Ub = 230.00, Ib = 5.000, Aa = 60.00)”.
Calibrate phase C, applying 120.00V, 1.000A, angle = 60.00º: “CAL (Uc = 120.00, Ic = 1.000, Aa = 60.00)”.
Calibrate Neutral line, applying 1.000A, angle = 60.00º with dominant phase: “CAL (In = 1.000, An = 60.00)”.
Calibrate a three phases system, applying to all phases 220.00V, 5.000A and a phase shift of 60.00º: “CAL (Ua = 220.00, Ia = 5.000,Aa = 60.00, Ub = 220.00, Ib = 5.000, Ab = 60.00, Uc = 220.00, Ic = 5.000, Ac = 60.00)”.
Calibrate a three phases system, including Neutral line, applying to all phases 220.00V, 5.000A and a phase shift of 60.00º: “CAL (Ua = 220.00, Ia = 5.000,Aa = 60.00, Ub = 220.00, Ib = 5.000, Ab = 60.00, Uc = 220.00, Ic = 5.000, Ac = 60.00, In = 5.000, An = 60.00)”.