Current Transformers Testing AEZCT-2000C

The AEZCT-2000C is Amperis’ third-generation microprocessor-based current transformer test set. Designed specifically for CT testing, the AEZCT-2000C has the following outstanding features:

Can greatly increase productivity and save time during the commissioning stage:

• Performs CT excitation, current-ratio, polarity, and phase angle tests
• Measures insulation resistance and winding resistance of the CT secondary windings
• Measures the CT’s load burden
• Standalone or computer-controlled via USB or Bluetooth wireless interface

The AEZCT-2000C’ test leads can be connected to all the CT output terminals, and the complete CT test can be performed automatically without any operator intervention.

Excitation Test

The CT excitation test is performed using the ANSI/IEEE C57.13.1 test method. Test voltage ranges from 50, 300, 500, 1200 and 2000 Vac can be selected for the excitation test. The test voltage is raised and lowered automatically by the AEZCT-2000C. The excitation test voltage and current data is collected and stored in the unit's internal memory. Knee point voltages (ANSI 10/50, IEC 60044, IEEE-30, IEEE-45) are calculated and printed on the test report. All of the test leads can be connected to the CT output terminals (X1, X2, X3, X4 and X5), and there is no lead switching required during testing. This convenient arrangement allows for testing any of the 10 possible combinations of X1 to X5. Up to 10 excitation tests can be stored in one record. Once the test is completed, the test report and CT excitation curves can be printed on the built-in thermal printer.

Demagnetization

The AEZCT-2000C automatically demagnetizes the CT under test when performing an excitation test.

User Interface and Display

The AEZCT-2000C features a back-lit LCD screen (240 x 128 pixels) that is clearly viewable in both bright sunlight and low-light levels. A "QWERTY"-style membrane keypad is used to enter test information and to control the unit’s functions.

Test Record Header Information

Test record header information, including the company, substation name, circuit ID, manufacturer, mode, CT serial number, and the operator’s name, can be stored with each record. 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.

Ratio and Polarity Tests

The CT current-ratio is determined using the ANSI/IEEE C57.12.90 measurement method. A test voltage is applied on any two terminals (X1 to X5) of the CT, and the induced voltage is measured through the H1 and H2 terminals of the CT. The CT current-ratio is displayed and also stored in memory. The current-ratio is measured from 0.8 to 5,000. 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. The CT current ratio error and phase displacement is also calculated based on the CT burden (or rated power) and rated current.

CT Winding Insulation Resistance Test Feature

The AEZCT-2000C offers an IR test feature that can also measure the insulation resistance of the CT’s secondary winding using a test voltage up to 1000 Vdc. The DC winding resistance reading range is from 2 to 500 Mega-ohms. The insulation resistance test results are displayed and printed on the report.

CT Burden Test

The AEZCT-2000C can measure the CT’s actual connected burden by injecting a 1A or 5A test current into the load. The CT burden measurements (Voltage, current, Cos φ, and burden impedance) are displayed on the screen and printed on the test report. This important test verifies the actual CT measured burden before putting the CT in service, thus avoiding any potential configuration conflicts.

Winding Resistance Test

The AEZCT-2000C can measure the DC resistance of transformer windings from 100 micro-ohms to 10 ohms.

Computer Interface

The AEZCT-2000C can be used as a standalone unit or can be computer-controlled. It can be connected to a PC via the USB port or wirelessly via Bluetooth. In computer-controlled mode, using the included CT Analysis Software, test records can be downloaded from the unit’s memory, or CT tests can be run from the PC. Test plans can also be created with the provided software. A test plan defines the various test parameters (test voltage, current range, nameplate ratios, etc.) and can be used to quickly perform tests. Additionally, tabulated test records are automatically exported to PDF, Excel, and XML formats for further analysis.

Thermal Printer

A 4.5-inch wide built-in thermal printer can print the CT test results and excitation curves.

Current Ratio and Phase Error Tables

As part of the tabulated test results, the AEZCT-2000C can also print the current ratio and current phase error tables.

Current Source

The AEZCT-2000C offers a programmable current source (0-20A, 0-15Vac) that can be used to verify CT loads. The on-time timer and output current are displayed on the LCD screen.

Internal Test Record Storage

The AEZCT-2000C can store up to 140 test records in Flash EEPROM. Each record may contain up to 10 excitation curves, burden test reports, current ratio readings, and polarity and DC resistance readings. Test records can be recalled and printed on the built-in thermal printer. They can also be transferred to a PC using the USB port, wirelessly via Bluetooth, or via the USB Flash drive interface port.

Internal Test Plan Storage

The AEZCT-2000C can store up to 128 CT test plans in Flash EEPROM. A test plan is comprised of the excitation test voltage, current range selection, CT nameplate ratios, and CT winding terminal combinations (X1 to X5) for each test and also includes the insulation test definition. Up to 10 test definitions can be stored per test plan. The ability to store test plans makes CT testing an extremely simple process. To perform a test, the AEZCT- 2000C is connected to the CT terminals and a test plan is selected to run.

Creating test plans for the AEZCT-2000C is also a simple process. A test plan can be created using the AEZCT-2000C’s keypad or can be created on a PC (with provided software) and then downloaded to the AEZCT-2000C via the USB port or Bluetooth. For added convenience, test plans can also be copied from a USB Flash drive to the AEZCT-2000C via the USB Flash drive interface.

External Data Storage

The AEZCT-2000C features a USB Flash drive interface that makes it very convenient to store and transfer test records and test plans. By using a USB Flash drive, test records and test plans can be quickly transferred between a computer and the AEZCT-2000C without the need to connect the unit to the computer.

AEZCT-2000C’s Specifications

Type	Portable current transformer test set
Physical specifications	19"W x 13"H x 16"D (48.3 cm x 33cm x 40.1 cm); Weight: 73 lbs (33.1 kg)
Input power	100 ¬ 120 Vac or 200 ¬ 240 Vac (factory pre-set), 50/60 Hz
Measurement method	ANSI/IEEE C57.12.90 and ANSI/IEEE C57.13.1 standards
Output test voltages	0 - 50 Vac @ 10A max; 0 - 300 Vac @ 10A max; 0 - 500 Vac @ 5A max; 0 - 1200 Vac @ 1.2A max; 0 - 2000 Vac @ 1A max
Current source	1 - 20A @ 0 - 15 Vac
Current source display	Test current and current on-time
Voltage reading range	0 - 2,200 Vac; Accuracy: ±1.0% of reading, ±1 volt
Current reading range	0 - 10A; Accuracy: ±1.0% of reading, ±0.02A
Current ratio range	0.8 - 999: 0.1%, 1000 - 1999: 0.3%, 2000 - 5000: 1%
Phase angle measurement	0 - 360 degrees; Accuracy: ±1.0 degree
Resistance reading range	100 micro-ohms ¬ 10 ohms; Accuracy: 2% of reading, ±1 count, ±10 micro-ohm
Insulation resistance test feature	2 Mega-ohms ¬ 500 Mega-ohms; Accuracy: 3% of reading, 500 ¬ 1000 Vdc test voltage
Display	Backlit LCD Screen (240 x 128 pixels; 114mm x 64mm); viewable in bright sunlight and low-light levels
Printer	Built-in 4.5-inch wide thermal printer
Computer interfaces	One USB port and Bluetooth wireless interface
External data storage	One USB Flash drive interface port (Flash drive not included)
PC software	Windows®-based CT Analysis software is included with purchase pric
Internal test record storage	Stores 140 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 6101A-1 and CAN/CSA C22.2 No 1010.1-92 standards
Environment	Operating: -10°C 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 cable set (X1-X5), one 35-foot H cable set, current source cables, insulation test cables, power cord, ground cable. A transportation case is included with the purchase price
Warranty	One year on parts and labor

NOTE: the above specifications are valid at nominal voltage and ambient temperature of +25°C (+77°F). Specifications are subject to change without notice