Instructional Literature
Page
30
Effective: May 2008
Instructions for the FP-6000 Protective Relay
For more information visit: www.eaton.com
IB02602004E
4.6.1.3 Selecting the “Energy” Sub-menu
This section allows the user to view the following Energy
parameters (See Display 6).
•
Watt Energy Hours (Forward, Reverse, Net)
•
Var Energy Hours (Lead, Lag, Net)
•
VA Hours
•
Start Date and Time stamp the Unit started measuring
Display 6. Energy Sub-menu.
The FP-6000 uses the positive sign convention for power
measurement. A positive sign convention corresponds to:
•
Inductive load implies positive Var and power factor values
with lagging or positive power factor.
•
Capacitive load implies negative Var and power factor values
with leading or negative power factor.
Hence the Forward watt-hours and the Lagging Var-hours are
positive, while the Reverse watt-hour and the Leading Var-hour
displays represent negative values.
The Forward watthours, Reverse watthours, Leading Var-hours,
Lagging Var-hours and VA-hours are all displayed as unsigned
numbers. However, when the FP-6000 calculates the Net
watthours and the Net Var-hours, the calculation is based on the
sign convention, therefore the Net watthours and the Net Var-
hours can be positive or negative values. Refer to the Power
Quadrant diagram in Figure 12.
A lagging power factor is displayed as a positive value and a
leading power factor is displayed as a negative value. The
maximum power factor is the most lagging power factor value
measured by the FP-6000 and the minimum power factor is the
most leading power factor value measured. Two examples for
min/max power factor values are shown in Figure 11.
The following examples define the sign convention for energy
under various power flow conditions:
•
Induction Motor Load (Figures 12 and 13)
Typically when monitoring induction motor loads, the power
flow is in Quadrant 1. The watts are positive and the power
factor is lagging. By definition, the power factor and Vars are
positive.
•
Capacitive Load (Figure 12)
When monitoring a capacitive load or a heavily excited
synchronous motor, the power flow is in Quadrant 4. By
definition, the power factor and Vars are negative.
Figure 11. Power Factor Minimum/Maximum.
Figure 12. Power Quadrants.
System Watt Hour
kWh Fwd
Magnitude
kWh Rev
Magnitude
kWh Net
Magnitude
System Var Hours
kVARh Lead
Magnitude
kVARh Lag
Magnitude
kVARh Net
Magnitude
System VA Hours
kVAh
Magnitude
Start Date
Date
mm/dd/yy
Time
hh:mm:ss
Reactive Power (+)
QUADRANT 2
QUADRANT 1
Watts Negative
Watts Positive
Vars Positive
Vars Positive
Power Factor Leading (-)
Power Factor Lagging (+)
Real Power (+)
Watts Negative
Watts Positive
Vars Negative
Vars Negative
Power Factor Lagging (+)
Power Factor Leading (-)
QUADRANT 3
QUADRANT 4
