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Perform Saturation, Ratio and Polarity Tests
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Perform CT Winding Resistance Test
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Fully Automated
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Test record header information including company, substation name, circuit ID, manufacturer, CT serial number, operator name, and test record-comments
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Plot Multiple Saturation Curves
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Store 140 Records (of 10 Saturation Curves)
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Computer Interface
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USB Flash drive interface
The EZCT-2000A is Vanguard’s third-generation microprocessor-based current transformer test set. The EZCT-2000A can perform the current transformer (CT) excitation test, measure the CT winding resistance and CT current-ratio automatically. All of the EZCT-2000A’s test leads can be connected to the CT output terminals (X1, X2, X3, X4 and X5), eliminating the need for lead switching during testing. Test voltage output is automatically raised and lowered by the EZCT-2000A without any operator intervention. With up to 2000 Vac excitation test voltage available, the EZCT-2000A can easily perform excitation tests on very large CT’s.
Excitation Test
The CT excitation test is performed using the
ANSI/IEEE C57.13.1, IEC 60044-1 test method.
The test voltage range for the CT excitation
test (50 Vac, 300 Vac, 500 Vac, 1200 Vac or
2000 Vac) can be selected, and then the test
voltage is raised and lowered automatically by
the EZCT-2000A. The excitation test voltage
and current data is collected and stored in the
unit’s internal memory. Any of the 10 possible
combinations of X1 to X5 can be tested since all
of the unit’s test leads can be connected to all of
the CT output terminals at the same time. Up to
10 excitation tests can be stored in one record.
Once the test is completed, test results can be
printed and excitation curves can be plotted on
the built-in 4.5-inch wide thermal printer.
Demagnetization
The EZCT-2000A automatically demagnetizes
the CT under test when performing an excitation
test.
Winding Resistance Test
The EZCT-2000A can also measure the DC resistance
of the CT winding under test. The DC
winding resistance measuring range is from 100
micro-ohms to 10 ohms.
CT Ratio and Polarity
Tests
The EZCT-2000A determines the CT current-ratio
using the ANSI/IEEE C57.12.90 measurement
method. A test voltage is applied on any two
terminals of the CT (X1 to X5), and the induced
voltage is measured through the CT’s H1 and H2
terminals. The CT current-ratio is displayed on
the screen and stored in memory. The current
ratio measuring range is from 0.8 to 5,000 to
1. The CT winding polarity is displayed as a “+”
sign (in-phase) or a “-” sign (out-of-phase) and
is annotated with the phase angle in degrees.
User Interface and
Display
The EZCT-2000A features a back-lit LCD screen
(240 x 128 pixels) that is viewable in both bright
sunlight and low-light levels. A rugged, alphanumeric,
membrane keypad is used to control
the unit.