EZCT-2000 USER’S MANUAL
REV 3
56
5.5 Troubleshooting
Guide
PROBLEM DESCRIPTION
Probable Cause
Suggested Solution
When running the
excitation test, the V
x
voltage is always zero.
The excitation current can
be raised during a test.
•
The EZCT-2000 X cables are driving a
short circuit.
•
Check CT shorting screws.
•
Check X lead connections.
When running the
excitation test, the V
x
voltage can be raised but
the excitation current is
always zero during a test.
•
The EZCT-2000 X cable is driving an
opened circuit.
•
Check the CT terminal connection.
CT excitation knee point
voltages and turns ratio
readings are incorrect.
•
CT may not be completely de-
magnetized.
•
If the user runs a dc resistance test,
the CT will be magnetized. The next
test the EZCT-2000 executes is an
excitation test. If the excitation
current did not reach at least 0.8A,
the CT is not completely de-
magnetized.
•
Raise the excitation voltage
setting in the test plan.
•
Re-run the excitation test.
•
You can quickly verify if the CT
was de-magnetized by looking at
the last excitation graph.
When running the
excitation test, the V
x
reading is erratic.
•
The EZCT-2000 X cable may be
opened. Each X cable has two
conductors going from the clip end to
the banana jacks. If one of the
conductors is opened, the V
x
readings
will be erratic.
•
Remove X cables from the EZCT-
2000 and the CT terminals.
•
Check cable integrity using an
Ohm Meter.
Saturation test is correct
but turns ratio test is
erroneous.
•
V
H
cables problem.
•
Check the V
H
cable connection.
•
Check the V
H
cable integrity with
an Ohmmeter
Turns ratio test of a CT
mounted on a
transformer bushing is
incorrect.
•
Transformer windings opposite side of
CT windings is not shorted.
•
See Figure 4.