Measurement Computing WavePort 312P rev.1.0 - Manual (Page 50)

5-2 Phaser Diagram PowerVista/312 User’s Manual
• Harmonics View: determines which tabulation will be displayed in the Phasor Harmonics Window.
• Update Rate: specifies the time between successive updates of the phasor diagram. Minimum update
time is 0.1 seconds and maximum is 5 seconds.
• Harmonics In Percent: chooses harmonic results in the Phasor Harmonics Window to be tabulated in
percent. If unchecked, values are displayed in Volts and Amps.
• Phasor Harmonic: is the harmonic for which a harmonic phasor diagram is displayed as one of the
graphic options. Values range from 1 to 50.
5.3 Phasor Diagram Application
The phasor diagram should be the first acquisition feature used when first connecting to an electrical system.
With this tool, one can gain the “pulse” of the power system and quickly spot potential problems. Several topics
are discussed below to aid the user in the application of the Phasor Diagram.
5.3.1 Phasing
With the Phasor Graphics Window set on Fundamental Phasors, the Phasor Diagram can be used to check
proper phase rotation and polarity of voltage and current connections. While Phasor Diagram acquisition is
active (updating in real time) there are several actions that can be performed directly via the software to make
connection changes. EasyPower Measure has been designed with a Phasing Toolbar so that once connections
have been made externally, all connection corrections can be made in software. In this way, physical
connections only need to be made once, thus limiting exposure to accidental shorts and direct contact. The
following procedure is suggested to correct any initial connections that are not producing a satisfactory phasor
diagram. If the Phasing Toolbar is not presently visible, use View / Phasing Toolbar to display it.
Three Phase Phasing Procedure:
1. Check voltages for a clean three phase arrangement, i.e. no phase inverted, and a clear 120 degree or near 120
degree displacement between vectors.
2. Correct voltage phase inversions by a toggling click on (this button for V1) the voltage phase invert button.
There is a button for each phase.
3. Check voltages for proper phase rotation, i.e. a V1, V2, V3 (or your desired rotation) order counter clockwise.
4. Correct voltage phase rotation using repeated clicks on which cycles through all phasing options, or use the
Configuration / System / Voltage Phasing/Inverting drop down list box to make a direct selection.
5. Check currents for a clean three phase arrangement, i.e. no phase inverted, and a clear 120 degree or near 120
degree (could vary a bit for single phase loads) displacement between vectors.
6. Correct current phase inversions by a toggling click on (this button for I1) the current phase invert button.
There is a button for each phase.
7. Check currents for proper phase rotation and alignment with their partner phase voltage, i.e. an I1, I2, I3 (or your
desired rotation) order counter clockwise.
8. Correct current phase rotation using repeated clicks on which cycles through all phasing options, or use the
Configuration / System / Voltage Phasing/Inverting drop down list box to make a direct selection.
Once the phasor diagram is acceptable, the watt and var results in the Phasor Demand Window should be
checked for reasonableness, i.e. proper sign for watts and vars and an appropriate power factor.
Figures 5-2
thru 5-6 are phasor diagrams for several system power factors. These are guides only and represent typical
balanced three phase systems.