Vanguard RFD-200 S3 - Manual (Page 24)

RFD-200 S3 USER’S MANUAL REV 1
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3.6 Using the RFD-200 S3 to Measure CT Primary and Secondary Currents
Use the steps below to measure the CT primary and secondary currents with the RFD-200 S3:
a. Connect the RFD-200 S3 current source through the CT primary current path as shown
in Figure 5.
b. Connect the CT secondary winding to the RFD-200 S3 [EXT INPUT CURRENT] input
as shown in Figure 5.
c. Turn on internal and external current display on the RFD-200 S3 by pressing the
[METER SELECT] key. You may have to press the key a few times till both the [RFD-
200 CURRENT] and the [EXT INPUT CURRENT] LED’s are illuminated.
d. Select ON from the control mode area.
e. Raise the test current to the desired setting.
f. The primary and secondary current readings will be displayed on the LCD screen as
shown below:
NOTE
The CT turns ratio can be calculated using the primary and secondary current
readings.
g. Return the test current to zero.
0mS 0.0CY
V Mtr: -0.003 V
Int I: 100.00 A
Ext I: 5.000 A