Rockwell Automation 1426 PowerMonitor 5000 Unit - Manual (Page 70)

70 Rockwell Automation Publication 1426-UM001F-EN-P - November 2013
Chapter 4 Metering
Symmetrical Component Analysis Results
The power monitor calculates sequence voltages and currents for use in
symmetrical component analysis, which transforms a set of unbalanced three-
phase vectors into three sets of balanced vectors. The positive sequence
components are a set of vectors that rotate the same direction as the original
power vectors, and represent that portion of the applied voltage or current
capable of doing work. Negative sequence components rotate opposite to the
original vectors, and represent the portion of the applied power that results in
losses due to unbalance. The percent unbalance value is the ratio between the
negative and positive current sequence in a three-phase system and is the most
accurate measurement of current unbalance because it takes into account the
magnitude of the individual currents and the relative phase displacement. The
zero sequence component is a single vector that does not rotate, and represents
ground or neutral current (I4) or voltage. The component analysis results are
included in the table above.
Setup
Only basic metering input setup is required for voltage and current metering.
Related Functions
• Metering result averaging
• Configuration lock
Viewing Metering Results by Using Web Page
You can view voltage, current, frequency, energy, and power metering results from
the PowerMonitor 5000 web page. Browse to the network address of the power
monitor. From the home page, choose the MeteringResults
folder and then the
desired
metering results page.