Operation: CP1SD/T/L Version
64
CENTRON® Polyphase Meter Technical Reference Guide
Definition 2:
The SiteScan system uses the A phase voltage as a reference point.
Therefore, the Toolbox Mode display of the A phase voltage angle will
always be 0.0°V. The CENTRON Polyphase meter is still determining
this angle and will still detect a problem if the A phase voltage angle is
incorrect.
A phase angle variations will manifest as errors in the other phases.
After the meter sets the A phase voltage direction to 0.0 degrees, the meter calculates all the
other voltage and current angles relative to the A phase voltage. This allows the user to
easily plot the vector information, not only to determine problems, but also to determine the
phase sequencing of the site.
The figure below provides an example of the plot for Toolbox Mode information. No matter
how the phasor information is plotted, whether the user plots the same as shown in the
figure below or in the opposite direction with 90° at the 12 o’clock position, the Toolbox
Mode will still provide an accurate representation of the site.
270
V
A
I
A
V
B
I
B
V
C
I
C
0
180
90
Figure 26: Plot of Toolbox Display Mode
In this example, the plot is going in the clockwise direction. Therefore, the phasors will be
rotating in the counterclockwise direction. By using this information, the phase sequencing
of the meter site can be determined. In the case shown, the A phase voltage is seen first. The
next voltage phasor is B phase and last is C phase voltage, indicating ABC rotation. For
CBA rotation, A phase voltage at zero will be seen first, but the user would see C phase
voltage next followed by B phase.
