The x-axis is time (in a 4-cycle measurement) and the y-axis is amplitude (i.e. volts & amps). The
primary y-axis is for the amplitude for voltage, and the secondary y-axis is for current.
The waveform display uses an auto-scaling function. This gives the user the ability to view both
currents and voltages efficiently when amplitude is much greater than the other.
When harmonic distortion is present, the waveform lines will appear uneven to display non-linear
load situations.
Leading or lagging power factor is displayed here. When the current waveform peaks after the
voltage waveform, the power factor is considered to be “lagging” and termed as an inductive load.
This is normal in most metering installations. When the current waveform peaks before the
voltage waveform, the power factor is considered to be “leading” and termed as a capacitive load.
A leading power factor is not as common in metering, but is normally seen when capacitor banks
are used in service installations when no load is present.
Phase rotation can easily be seen in this graph as well. Whichever phase voltage “peaks” first in
time determines the phase rotation. If the A phase voltage displays its peak first in the waveform,
the rotation is considered to be ABC. In the graph above, the rotation is ABC since A phase
voltage displays its full peak first.
Rev 1.5
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