63230-300-212 Chapter4—Metering Capa bilities
April 2001 Energy R eadings
65
© 2001 Schneider Electric All Rights Reserved
Forconditional accumulated energy readings,you can set the real, reactive,
andapparent energy accumulation to OFF or ON when a particular condition
occurs.You can do this overt hecommunications link, using a command, or
froma digital input change. For example, youmay want to track accumulated
energyvalues during a particular process that is controlled by a PLC. The
circuitmonitor stores the date and time of the last reset of conditionalenergy
in nonvolatilememory.
Also,the circuit monitor provides an additional energy readingthat is only
available over the co mmunications link :
•Four-quadrantreactive accumulated energy readings. The circuit
monitoraccumulates reactive energy (kVARh)in four quadrantsas shown
inFigure 4–7. The registers operatein unsigned (absolute) mode in which
the circuit monitoraccumulates energy as positive.
NOTE: The reactiveaccumulated energy is not affected by the VARsignconventionand will remain as shown in the image below.Figure 4–7: Reactive energy accumulates in four quadrants
Real
Power
In
Reactive
Power In
Quadrant
1
Quadrant
2
Quadrant
3Quadrant
4
Reverse Power Flow Normal Power Flow
watts negative (–)
vars positive (+)
power factor leading (+)
watts negative (–)
vars negative (–)
power factor lagging (–)
watts positive (+)
vars negative (–)
power factor leading (+)
watts positive (+)
vars positive (+)
power factor lagging (–)