When transformers fail, it can often be due in part to heat exposure over long periods of operational time. Regular testing is always a good idea in order to keep transformers operational, prevent power interruption and possible damage to electrical equipment systems. By scheduling a system for regular diagnostic testing, problems are detected early, helping to extend the life of this important equipment while also reducing the chance of accidents.
Vanguard offers their EZCT-2000A Automated CT Test Set to accurately measure what is going on inside your transformers. This durable automated system can test turns ratio, winding polarity and excitation current without the need for bushing or current transformer removal all using a microprocessor based process. The Vanguard EZCT-2000A Automated CT Test Set allows simplified testing in the field with results printed using the onboard thermal printer or stored for later retrieval using a PC or laptop.
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 test set automatically demagnetizes the CT under test when performing an excitation test
Winding Resistance Test
The DC winding resistance measuring range is from 100 micro-ohms to 10 ohms.
CT Ratio and Polarity Test
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.
User Interface and Display
The Vanguard EZCT-2000A features a back-lit LCD screen that is viewable in both bright sunlight and low-light levels.
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.
Internal Test Plan Storage
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.
External Data Storage
The Vanguard EZCT-2000A features a standard USB Flash drive interface that makes it convenient to store and transfer test records and test plans.
The test set can be used as a stand-alone unit or can be computer-controlled via the built-in RS-232C or USB interfaces.
A built-in 4.5-inch wide thermal printer can print the current transformer test report and plot the excitation curves.