TD 17271 A
QUADRANT
2
WATTS NEGATIVE
VARS POSITIVE
VA RS
POWER FACTOR LAGGING
REVERSE POWER FLOW
WATTS N EGATIVE
VARS N EGATIVE
POWER FACTOR LEADING
QUADRANT
3
QUADRANT
1
WATTS POSITIVE
VARS POSITIVE
POWER FACTOR LEADING
EXAMPLE: C A PACI TIVE LOAD
N ORMAL POWER FLOW
WATTS POSITIVE
VARS NEGATIVE
POWER FACTOR LAGGING
EXAMPLE: INDUCTIVE LOAD
QUADRANT
4
Figure
3.2
Power Quadrants
WATTS
3.2.1.1
Blinking LEOs: Watts, Vars and/or Power Factor
To display reverse power flow, lagging (negative) power fac
tor, and negative var, the menu select LED being viewed will
blink. If it is not blinking the values are positive (leading). Refer
to Figures 3.2, 3.3, 3.4 for a further explanation.
LINE
POWER FLOW
-------
CURRENT T RANSFORMER
Figure
3.3
Induction Motor Load
15
IQ DATA P LUS I I
3.2.1.2
Monitoring Inductive Loads -
Typically when
monitoring induction motor loads the power flow is in Quad
rant 4. The watts are positive and the power factor is lagging.
I
LINE
BREAKER A
)
BREAKER C
I
LINE
BREAKER B
)
MOTOR LOADS
MOTOR LOADS
Figure
3.4
Po
we
r Distribution
Thus by definition the power factor and var will be negative
and the LEOs will blink for these two values. Refer to Figure
3.3.
3.2.1.3
Power Factor Correction Capacitors
-
When
monitoring a load that also has power factor correction capa
citors and/or leading power factor synchronous motors such
that the net load is capacitive, then the power flow is in Quad
rant
1.
In this case, none of the LEOs will blink.
3.2.1.4
Power Distribution -
Referring to Figure 3.4, three
conditions typically can be encountered.
Condition
1:
Breaker
A &
B closed, Breaker C open. Power
flow is in Quadrant 4. The power factor and var will be nega
tive and their respective LEOs will blink.
Condition 2: Breaker
A &
C closed, Breaker B open. Power
flow for Breaker
A &
C is in Quadrant 4. The power factor and
var will be negative, and thus the LEOs will be blinking for
power factor and var readings.
Condition 3: Breaker B
&
C closed, Breaker
A
open. The
power flow for Breaker B is in Quadrant 4 and the metering
condition is the same as condition
1 &
2. But the power flow
for Breaker C is reversed and will be in Quadrant 2. Only the
watts LED and power factor LED will blink .
3.2.2
Units LEOs: Auto range units for monitoring -
Units,
kilo, mega. Refer to Figure 3.1.
