Calibration of three-phase revenue meters under distorted waveform conditions

Increased awareness of the effect of harmonics on metering instrumentation has led to the establishment of a versatile three phase nonsinusoidal calibration system. Major North American meter manufacturers have already taken advantage of this facility to verify the accuracy of their new designs under distorted waveform conditions. Tests on existing meters have shown that energy meters are only moderately affected by the distortion. However, kVA maximum demand meters can exhibit very large errors. A need for inclusion in the national standard requirements limiting errors of the kVA demand meters operating under nonsinusoidal conditions is demonstrated