YOKOGAWA CW140, User Manual, Page: 137 / 292

12-17
IM CW140-E
Harmonics Measure Mode
12
12.6 Computational Expressions
●
Polarities of Data Items in Harmonics Measure Mode
The polarities of data items "power," "phase angle of power" and "power
factor" are as follows.
• With reactive power meter method:
Lag Lead
180 180 Phase difference
Power
Phase angle of power
Power factor –
+
–
+
+
+ +
+
+
–
–
+
90 90 0
• Without reactive power meter method:
Lag Lead
180 180
Phase difference
Power
Phase angle of power
Power factor –
+
–
+
+
+ +
+
+
–
+
–
90 90 0
• The phase lag or lead means that of current in reference to voltage.
• Direction of harmonic current
The direction of harmonic current can be identified according to the polarity of
power, as shown below.
If the polarity of power is positive (+), the current is flowing inward.
If the polarity of power is negative (–), the current is flowing outward.
TIP
The CW140 calculates the Harmonics Measure-mode total rms values of voltage/current and power by
summing the rms values of their respective fundamental wave components and 1st- throgh 13th-order
harmonic components. Consequently, these total rms values may differ from those of the Instant Mea-
sure mode.