IQ DP-4000
SECTION 3 - OPERATOR PANEL
TD 17548B
10
Note:
The following examples assume that the unit is
using the mathematic sign convention.
•
Watts, Vars and/or Power Factor. The selected
LEDs blink when viewing reverse power flow,
lagging (negative) Power Factor, and negative
Vars. The LEDs do not blink if the values are
positive (leading). Refer to Figures 3.2, 3.3, 3.4 and
3.5 for further explanation.
•
Induction Motor Loads. Typically when monitoring
induction motor loads the power flow is in Quadrant
4. The Watts are positive and the Power Factor is
lagging. By definition, the Power Factor and Vars
are negative and the LEDs will blink for these two
values. Refer to Figure 3.2.
•
Power Factor Correction Capacitors. When
monitoring a load that also has Power Factor
correction capacitors and/or leading Power Factor
synchronous motors so that the new load is
capacitive, then the power flow is in Quadrant 1. In
this case, none of the LED’s will blink.
•
Power Distribution. Typically you will encounter
three conditions when monitoring power distribution
(Refer to Figure 3.5 p.10):
1. Breakers A and B are closed and C is
open. Power flow is in Quadrant 4. The
Power Factor and Vars will be negative and
the respective LED’s will blink.
2. Breakers A and C are closed and B is
open. Power flow for Breaker A and C is in
Quadrant 4. The Power Factor and Vars
will be negative, and the LED’s will blink for
Power Factor and Vars readings.
3. Breakers B and C are closed and A is
open. The power flow for Breaker B is in
Quadrant 4 and the metering condition is
the same as Conditions 1 and 2. However,
the power flow for Breaker C is reversed
and is in Quadrant 2. Only the Watts LED
and Power Factor LED will blink.
Reactive Power
QUADRANT 2
↑
QUADRANT 1
Watts Negative
Watts Positive
Vars Positive
Vars Positive
Power Factor Lagging (-)
Power Factor Leading (+)
Real Power
→
Watts Negative
Watts Positive
Vars Negative
Vars Negative
Power Factor Leading (+)
Power Factor Lagging (-)
↓
QUADRANT 3
QUADRANT 4
Figure 3.2 Power Quadrants, Mathematical
↑
QUADRANT 2
QUADRANT 1
Watts Negative
Watts Positive
Vars Negative
Vars Negative
Power Factor Lagging (+)
Power Factor Leading (-)
Real Power
→
Watts Negative
Watts Positive
Vars Positive
Vars Positive
Power Factor Leading (-)
Power Factor Lagging (+)
QUADRANT 3
↓
QUADRANT 4
Reactive Power
Figure 3.3 Power Quadrants, Power Engineer's Sign
Convention
Summary of Contents for Cutler-Hammer IQ DP-4000
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