A current transformer (CT) transforms higher current into a more manageable secondary current during normal operation. This change is made possible by copper coils wrapped around an iron core, with the ratio between primary and secondary currents determined by the ratio between the number of primary and secondary turns.
When current flows through the primary winding, the following actions occur:
• The iron core inside the transformer is magnetized.
• The magnetic field in the iron core induces a voltage in the secondary coils.
• If the secondary circuit is closed, a current flows through the secondary circuit in proportion to the CT ratio.
The Vanguard EZCT-2000A CT Tester microprocessor-based Current Transformer Test Set can perform the Current Transformer (CT) excitation test, measure the CT winding resistance and CT current-ratio automatically.
All of the Vanguard EZCT-2000A ’s test leads can be connected to the CT output terminals, eliminating the need for lead switching during testing. Test voltage output is automatically raised and lowered by the Vanguard EZCT-2000A without any operator intervention. With up to 2000 Vac excitation test voltage available, the Vanguard EZCT-2000A can easily perform excitation tests on very large CT’s.
Vanguard EZCT-2000A CT Tester features:
• Conducts excitation, winding resistance, winding polarity and current-ratio tests
• 20X4 back-lit LCD screen
• Alphanumeric keypad
• Variable output test voltages from 0-50 VAC at 10 Amperes, 0-1200 VAC at 2 Amperes and 0-2000 VAC at 1.2 Amperes
• Measures current from 0-10 Amperes
• Measures winding resistance from 100 μΩ up to 10 Ω
• Measures current-ratio from 0.8 to 5,000
• Can measure phase angle from 0-360 degrees
• 4.5 inch wide thermal printer
• Can store 140 current transformer test records
• Stores 128 test plans
• USB flash drive port for extra storage
• USB and RS232 interfaces allows you to attach the device to a computer for remote-controlled operation and data analysis