User's Manual

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30 November 2006 5-7
REX Meter
Technical Manual 5 Testing
Figure 5-3. Location of the test LED pulse output
Formulas Used in Testing
When testing the REX meter, manual calculations may be necessary to verify
meter quantities. Table 5-3 shows the naming conventions used to indicate
variable quantities in these calculations.
Table 5-3. Variables used in manual calculations
Test
LED
Meter nameplate
Variable Represents
CTR Current transformer ratio
Kh
meter
Wh test constant of the meter (watthours per pulse-period)
Kh
std
Wh constant of reference standard (watthours per pulse-period)
kW Power in kilowatts
P Number of pulses of the square indicator on the LCD or pulses
from the test LED, where each flash or pulse is 1 Kh
meter
.
p Number of pulses of the reference standard
t Time (in minutes)
VTR Voltage transformer ratio