Current Transformer Test Set EZCT 2000A

The EZCT-2000A is Amperis' 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.

View an usage demostration

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.

CT Ratio and Polarity Test

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 currentratio 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.

CT 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.

User Interface and Display

The EZCT-2000A features a back-lit LCD screen (240 x 128 dot graphic) that is viewable in both bright sunlight and low-light levels. A rugged, alpha-numeric, membrane keypad is used to control the unit.

Thermal Printer

A built-in 4.5-inch wide thermal printer can print the current transformer test report and plot the excitation curves.

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.

Internal Test Record Storage Capacity

The EZCT-2000A can store up to 140 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.

Internal Test Plan Storage Capacity

The EZCT-2000A 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-2000A is connected to the CT terminals and a test plan is simply selected and run. Test plans can be created on the EZCT-2000A itself or created on a PC and downloaded to the EZCT-2000A via the unit's built-in RS-232C or USB interfaces.

External Data Storage

The EZCT-2000A 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-2000A without the need to connect the unit to the computer.

Computer Interface

The EZCT-2000A can be used as a stand-alone unit or can be computer-controlled via the built-in RS-232C or USB interfaces. A Windows® XP/Vistabased Current Transformer Analysis software application is provided with each EZCT- 2000A. This software can be used to retrieve test records from the EZCT-2000A, create test plans, download test plans to the EZCT-2000A, and can also be used to run CT tests from the PC. Tabulated test records can be exported in Microsoft® Excel format.