2.2.1.2 Calculating Phase Calibration Factor Using Pulse Calibration Error

There is another method to calibrate the phase delay: using the CF pulse error.

Before calibrating the phase delay, set PF to 0.5Lag (inductive), CAL_PH_Ix (x = A, B, C, N) and CAL_PH_Vx (x = A, B, C) to 0x00000000.

The following formulas are used to calibrate the phase of phase x:

Example:

After magnitude calibration, pulse measurement of a single channel at PF=0.5Lag (50 Hz) shows initial channel accuracy of 99.638%, equivalent to a -0.362% error.

The intermediate quantity (6.6527e-4) above, corresponds to a phase shift of +0.12° at 50 Hz, but needs to be normalized to an equivalent linear-phase shift at 60 Hz of +0.144°. All phase shift coefficients used by the metrology DSP must be normalized to equivalent linear-phase shift values at 60 Hz.