Vanguard EZCT-10 - Manual (Page 2)

EZCT-10
current transformer test set
The EZCT-10 is a microprocessor-based, current-transformer test set. This rugged and
portable test set can perform the current transformer (CT) excitation, CT current-ratio,
and winding polarity tests. Current transformers can be tested in their fi eld-mounted
confi guration, eliminating the need to remove bushings or current transformers from
the host equipment.
The EZCT-10 uses a heavy-duty transformer to perform the CT excitation test. It is ca-
pable of outputting 50 Vac at 10A and 200 Vac at 10A.
Part number EZCT-10 EZCT-10, cables, and PC software
Part number EZCT-10-CASE EZCT-10 shipping case
Part number Paper-TP4 thermal printer paper
ordering information
2
Excitation Test
The CT excitation test is performed using the
ANSI/IEEE C57.13.1, IEC 60044-1 test method.
The EZCT-10 applies an AC variable test voltage
(up to 1,200 Vac) to the CT’s secondary wind-
ings. The EZCT-10 records and displays the test
voltage and excitation current applied to the
current transformer during the excitation test.
Once tests are completed, up to 10 excitation
curves and knee-point voltages of the tests can
be plotted on the built-in thermal printer. IEEE-
30, IEEE-45, ANSI/IEC 60044-1 (10/50) knee
point voltages are also calculated and printed
on the test report.
Internal Test Record
Storage
The EZCT-10 can store up to 128 current-trans-
former test records in Flash EEPROM. Each test
record may contain up to 10 excitation curves,
polarity, and current-ratio test data sets. Test re-
cords can be recalled and printed on the built-in
thermal printer.
Computer Interface
The EZCT-10 can be used as a stand-alone unit
or can be computer-controlled via the built-in
RS-232C or USB interfaces. Windows®-based
Current Transformer Analysis software is pro-
vided with each EZCT-10. This software can be
used to retrieve test records from the EZCT-10
and can also be used to run CT tests from the
PC. Tabulated test records can be exported in
PDF, Excel, and XML formats for further analysis.
CT Ratio and Polarity
Tests
The EZCT-10 determines the CT current-ratio
using the ANSI/IEEE C57.12.90 measurement
method. A test voltage is applied on the CT’s
X terminals and the induced voltage is mea-
sured across the CT’s H1 and H2 terminals. The
current-ratio is displayed on the screen and
stored in memory. The current-ratio measuring
range is from 0.8 to 5,000. Winding polarity is
displayed as a “+” sign (in-phase) or “-” sign
(out-of-phase) and is annotated with the phase
angle in degrees.
User Interface
The EZCT-10 features a back-lit LCD screen (4
lines by 20 characters) that is viewable in both
bright sunlight and low-light levels. A rugged,
alpha-numeric, membrane keypad is used to
enter test information and to control the unit’s
functions, and a voltage control knob is used to
control the variable test voltage output. The test
voltage range (50V at 10A, 200V at 10A, 1,200V
at 1.5A) is selected with a switch on the control
panel.
Built-in Thermal Printer
A built-in 4.5-inch wide thermal printer can print
the current transformer test report and plot the
excitation curves.
EZCT-10 connections