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CT/PT Ratio Tester
The CT/PT Ratio Tester is designed to carry out routine accuracy and linearity tests on the LIF CT, isolating CT and single phase voltage measuring transformer used in control cubicles of traction and auxiliary converter. The system consists of a variable voltage, programmable sine wave generator with very low harmonic distortion for generating an excitation signal for the CT/PT under test. This sine wave is fed to a low distortion and low impedance power amplifier which can be configured as a voltage or current amplifier for feeding adequate power in the primary of the CT/PT. The input of the CT/PT is ramped up or down using electronic control hardware. The output of the CT/PT is connected to a pre-selected Burdon Resistor and is read by the system through a scaling amplifier and signal conditioning circuit to find ratio and linearity of the CT/PT under test.


  • CT ratio in the range 300:1
  • PT ratio in the range 1:1


  • The system uses a microprocessor-based control logic for easy usage, enhanced measuring accuracy and also for allowing future upgrades for data connectivity
  • Robust 5A and 30A current sources for testing LIF and isolating CTs
  • Capable of testing ring type, as well as two winding CTs
  • A large LCD screen allows the user to view the input and output parameters as well as their ratio, thus eliminating manual calculations
  • The test set is built in a 19" DIN standard chassis which can be easily rack-mounted