Vanguard RFD-200 S3 - Manual (Page 22)

RFD-200 S3 USER’S MANUAL REV 1
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3.5 Using the RFD-200 S3 to Plot a Current Transformer Excitation Curve
Use the steps below to find the excitation curves of a current transformer (CT):
a. Connect the RFD-200 S3 AC voltage source to the CT secondary winding in series with
the external current input as shown in Figure 4.
b. Connect the RFD-200 S3 AC voltage source to the RFD-200 S3 external voltage meter as
shown in Figure 4.
c. Select ON from the control mode area.
d. Slowly raise the AC test voltage. Observe and record the excitation voltage and current
displayed on the LCD screen.
e. Continue to raise the test voltage and record the excitation voltage and current
readings.
f. When the excitation current reaches saturation (from 1.5A to 2.0A), lower the voltage
to zero.
g. You can now plot the CT excitation curves using the collected voltage and current
readings.