Siemens ACCESS 9340 - Power Factor Sign Conventions

© 2008 Siemens Energy & Automation, Inc. All Rights Reserved.
PMCM-9340D-0208 ACCESS 9340 and 9360 Meters
2/2008 Chapter 4—Metering Capabilities
EN–43
An alternate power factor storage method is also available for use
with analog outputs and trending. See the footnotes in “Register List”
on page 122 for the applicable registers.
Power Factor Sign Conventions
The meter can be set to one of two power factor sign conventions:
IEEE or IEC. The ACCESS 9340/9360 defaults to the IEEE power
factor sign convention. Figure 4–2 illustrates the two sign
conventions. For instructions on changing the power factor sign
convention, refer to “Advanced Meter Setup Options” on page 26.
Figure 4–2: Power factor sign convention
Real
Power
In
watts negative (–)
vars positive (+)
power factor (–)
watts positive (+)
vars positive (+)
power factor (+)
watts negative (–)
vars negative (–)
power factor (–)
watts positive (+)
vars negative (–)
power factor (+)
IEC Power Factor Sign Convention
Reverse
Power Flow
Normal
Power Flow
Reactive
Power In
Quadrant
2
Quadrant
1
Quadrant
3
Quadrant
4
watts negative (–)
vars positive (+)
power factor (+)
watts positive (+)
vars positive (+)
power factor (–)
watts negative (–)
vars negative (–)
power factor (–)
watts positive (+)
vars negative (–)
power factor (+)
Reactive
Power In
Real
Power
In
IEEE Power Factor Sign Convention
Reverse
Power Flow
Normal
Power Flow
Quadrant
2
Quadrant
1
Quadrant
3
Quadrant
4
Figure 4–3: Power Factor Display Example
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d
f
g
h
h
h
h
The power
factor sign is
visible next to
the power factor
reading.