Description

The EZCT-2KA is Vanguard’s third-generation microprocessor-based current transformer test set. The EZCT-2KA can perform the current transformer (CT) excitation test, measure the CT winding resistance and CT current-ratio automatically. All of the EZCT-2KA’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-2KA without any operator intervention. With up to 2000 Vac excitation test voltage available, the EZCT-2KA can easily perform excitation tests on very large CT’s.

• Perform Saturation, Ratio and Polarity Tests
• Perform CT Winding Resistance Test
• Fully Automated
• Test record header information including company, substation name, circuit ID, manufacturer, CT serial number, operator name, and test record-comments
• Plot Multiple Saturation Curves
• Store 1,000 Records (Each test record may contain up to 10 sets of excitation, resistance, and ratio data)
• USB and Bluetooth computer interface
• USB Flash drive interface
• Furnished with full set of test leads

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-2KA. 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.

CT Ratio and Polarity Tests
The EZCT-2KA 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 10,000 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.

Demagnetization
The EZCT-2KA automatically demagnetizes the CT under test when performing an excitation test.

Winding Resistance Test
The EZCT-2KA can also measure the DC resistance of the CT winding under test. The DC winding resistance measuring range is from 100 micro-ohms to 20 ohms.

User Interface
The EZCT-2KA features a back-lit LCD screen (240 x 128 pixels) that is viewable in both bright sunlight and low-light levels. A rugged, “QWERTY”-style, membrane keypad is used to control the unit.

Internal Test Record Storage
The EZCT-2KA can store up to 1,000 test records in Flash EEPROM. Each test record may contain up to 10 excitation curves, current-ratio readings, polarity and DC resistance readings. Test records can be recalled and printed on the built-in thermal printer.

External Data Storage
The EZCT-2KA features a standard USB Flash drive interface that makes it very convenient to store and transfer test records and test plans. By plugging in a USB Flash drive, you can quickly transfer your test records and test plans between a computer and the EZCT-2KA without the need to connect the unit to the computer.

Internal Test Plan Storage
The EZCT-2KA can store up to 128 CT test plans in Flash EEPROM. A test plan defines the excitation test voltage and current range selection, CT nameplate ratio, and CT winding terminals (X1 to X5) for each of the tests. Up to 10 test definitions can be stored per test plan. The use of a test plan greatly simplifies the CT testing process; the EZCT-2KA is connected to the CT terminals and a test plan is simply selected and run. Test plans can be created on the EZCT-2KA itself or created on a PC and downloaded to the EZCT-2KA via the unit’s built-in USB or Bluetooth interfaces or transferred to the unit using a USB flash drive.

Test Record Header Information
Test record header information can include the company name, substation name, circuit ID, manufacturer, CT serial number, operator’s name and test record comments. In addition to the test record header, a 20-character test description for each test in the record (10 tests per record) can also be entered.

SPECIFICATIONS

TYPE Portable current-transformer test set PHYSICAL SPECIFICATIONS Dimensions: 17”W x 12.5”H x 12”D (42.7 cm x 32.0 cm x 26.9 cm) Weight: 48 lbs (21 Kg) INPUT POWER 100 – 120 Vac or 200 – 240 Vac (factory pre-set), 50/60 Hz MEASUREMENT METHOD IEC 60044-1, IEC 61869, ANSI/IEEE C57.13.1, and ANSI/IEEE C57.12.90 CURRENT RATIO RANGE 0.8 – 999: ±0.1%, 1000 – 1999: ±0.3%, 2,000 – 4,999: ±1%, 5,000 – 10,000: ±1.5% OUTPUT TEST VOLTAGES 0 – 50 Vac @ 10A max, 0 – 300 Vac @ 8A max, 0 – 500 Vac @ 5A max, 0 – 1,200 Vac @ 2A max, 0 – 2,000 Vac @ 1.2A max RESISTANCE MEASUREMENT Range: 100 µΩ to 20 Ω; resolution: 1 µΩ Accuracy: 100 µΩ – 1.99 Ω (2% of reading ±10 µΩ), 2 Ω – 20 Ω (1.5% of reading ±2 mΩ) VOLTAGE READING RANGE 0 – 2,200 Vac; accuracy: ±1.0% of reading, ±1 volt CURRENT READING RANGE 0 – 10 A; accuracy: ±1.0% of reading, ±0.02A DISPLAY back-lit LCD screen (240 x 128 pixels) viewable in bright sunlight and low-light levels PHASE ANGLE MEASUREMENT 0 – 360 degrees; accuracy: ±1.0 degree PRINTER built-in 4.5” wide thermal printer COMPUTER INTERFACES one USB port, bluetooth PC SOFTWARE Windows®-based CT analysis software is included with purchase price EXTERNAL DATA STORAGE One USB Flash drive interface port (Flash drive not included) INTERNAL TEST RECORD STORAGE stores 1,000 test records. Each test record may contain up to 10 sets of excitation, resistance and ratio data INTERNAL TEST PLAN STORAGE stores 128 test plans. Each test plan can store 10 excitation test voltage and current settings SAFETY designed to meet UL 61010A-1 and CAN/CSA C22.2 No. 1010.1-92 standards TEMPERATURE Operating: -10˚ to 50˚ C (15˚F to +122˚ F); Storage: -30˚ C to 70˚ C (-22˚F to +158˚ F) HUMIDITY 90% RH @ 40°C (104°F) non-condensing ALTITUDE 2,000 m (6,562 ft) to full safety specifications CABLES one 20-foot (6.10m) X cable sets, one 35-foot (10.69m) H cable set, power cord, USB cable, cable carrying bag OPTIONS shipping case WARRANTY one year on parts and labor Specifications are valid at nominal voltage and ambient temperature of +25˚C (+77˚F).