Megger MPRT 8430 - Single Phase Applications; AC and DC Voltage Transducers

30°. The calculated Power Factor (displayed next to Power Factor 3 Element) would
be,
COS -30° = - 0.866 PF
For this example, let's assume the measured output current from the transducer is -
0.489 mA dc. Based on a Lead/Lag value of ±1 mA equals ±0.5 PF, the scaling would be
equal to
0.5 PF = COS 60°
1 mA / 60° or 0.016666 mA per degree.
Therefore, the displayed PF in the Transducer Output section of the Transducer Test
Screen should read
- 0.489 mA/ 0.016666 mA/Degree = - 29.35 Degrees
COS - 29.35° = - 0.871 PF
Power factor transducer accuracies are stated in units of Power Factor, not in % error.
Therefor, the Accuarcy window for Power factor transducers needs to change from %
error to ± 0.000 PF. For the above example the Accuracy displayed in the Transducer
Output section would be equal to the following,
0.871 - 0.866 = + 0.005 PF
If the accuracy of the transducer were a ± 0.01 PF, then the firmware would compare the
accuracy values between the Setting Screen and the Test Screen and would display
PASS in the Transducer Output section of the test screen.
3.8.10.8 Single Phase Applications
As previuously described, transducers come in three-phase and single phase
configurations. In the Transducer Setting Screen, the operator is required to select what
type of transducer is to be tested. Once selected, the internal firmware of the MPRT unit
will make certain assumptions and calculations based on the type of transducer selected.
The following are detailed descriptions of the single phase AC Volts, AC Current, DC
Volts, DC Current and Frequency transducers.
3.8.10.8.1 AC and DC Voltage Transducers
The single phase AC and DC voltage transducer requires 1 voltage output channel to
test. The MPRT will automatically select the first voltage channel available, V1. The test
will initially start at the default value voltage that is set in the Default Setting Screen. For
example, 120 Volts L-N. When the user inputs the MAX. Volts value in the Transducer
Setting Screen, the firmware can set the required test voltage for full scale value. Note:
to power up the amplifier of some transducers, V2 may be selected to provide the AC
voltage source. Remember to select the proper output voltage for V2 (it will default to the
MAX value in the setting screen). If V2 is not available, use another appropriate source.
Example: The default voltage is 120.00 Volts AC, and the user inputs 150 Volts AC as
Max. Value. When the user inputs 150 Volts in the MAX. value window, in the Test
Screen the test set should automatically show a test voltage value of 150 Volts at an
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