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5
Chapter
Verifying Meter Functionality
It is very important to verify that the CTs of the RSM-5c and RSM-5 are
properly installed. Follow the steps below to verify the voltage, kWh reading,
current, and power.
I. Verifying Voltage
1) Press and hold the Display Scroll button until the following menu heading
is displayed:
2) Release the Display Scroll button. Scroll down by pressing and releasing
the Display Scroll button until the "Volts" screen is displayed (examples
shown for 120V, 277V, and 347V):
3) Verify that phases A, B, and C are displaying voltages within normal
range, which is -10% to +10% of the rated voltage.
II. Verifying kWh Reading
1. Press and hold the Display Scroll button until the following menu is
displayed:
2. Release the Display Scroll button. Scroll down by pressing and releasing
the Display Scroll button until the following screen is displayed, indicating
the All Hours kWh reading for the meter:
3. Verify that the kWh value increases on the LCD (assumes active load).
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© COPYRIGHT
2008
www.quadlogic.com
III. Verifying Current and Power
1. Press and hold the Display Scroll button. Scroll down by pressing and
releasing the Display Scroll button until the following menu heading is
displayed:
2. Release the Display Scroll button. Scroll down by pressing and releasing
the Display Scroll button until the following screen is displayed:
The A(mperage) reading is the indication of current. The A(mperage) reading
in the display above will always be a positive number, even if the CT was
incorrectly installed. Check the reading, and using the correct multiplier, see
if it indicates the approximate expected current. Remember that this applies
to Phase 1 only. If all the numbers on the multiplier screen (under the Phase
Diagnostics menu in the Display Menu Structure) were 1.00 and the current
transformers are 100:0.1, the correct multiplier is 1 and the readings are
the actual values seen on the LCD. If the CT's are 200:0.1, multiply the LCD
reading by 2.
The W(att) reading is the indication of power. The W(att) reading counts
forward when viewed on the LCD. A negative power reading is indicative of
an incorrectly installed CT, or one that is cross-phased with the wrong voltage
(phase) leg. The R(eactive) reading can be negative, depending on the nature
of the load. Negative values indicate a capacitive load while positive values
indicate an inductive load.
3. Scroll down by pressing and releasing the Display Scroll button until the
following screen is displayed:
Under normal conditions the phase angle (x.x˚) should be between -30˚ and
+30˚ (refer to Figure 5-1) and the power factor should be a number between
0.80 and 1.0.
© COPYRIGHT
2008
- Verifying Meter Functionality -
Chapter 5
www.quadlogic.com
16
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