Schneider Electric 4000 manual April Energy Readings, Real Power

63230-300-212	Chapter 4—Metering Capabilities
April 2001	Energy Readings

For conditional accumulated energy readings, you can set the real, reactive, and apparent energy accumulation to OFF or ON when a particular condition occurs. You can do this over the communications link, using a command, or from a digital input change. For example, you may want to track accumulated energy values during a particular process that is controlled by a PLC. The circuit monitor stores the date and time of the last reset of conditional energy in nonvolatile memory.

Also, the circuit monitor provides an additional energy reading that is only available over the communications link:

•Four-quadrant reactive accumulated energy readings. The circuit monitor accumulates reactive energy (kVARh) in four quadrants as shown in Figure 4–7.The registers operate in unsigned (absolute) mode in which the circuit monitor accumulates energy as positive.

NOTE: The reactive accumulated energy is not affected by the VAR sign convention and will remain as shown in the image below.

Reactive

Power In

	Quadrant	Quadrant
2		1
watts negative (–)		watts positive (+)
vars positive (+)		vars positive (+)
power factor leading (+)		power factor lagging (–)
	Reverse Power Flow	Normal Power Flow
watts negative (–)		watts positive (+)
vars negative (–)		vars negative (–)
power factor lagging (–)		power factor leading (+)
	Quadrant	Quadrant
3		4

Real

Power

In

Figure 4–7: Reactive energy accumulates in four quadrants

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