The Three-Phase Winding Ohmmeter TWA25A is designed for six-winding resistance measurement of both the primary and the secondary transformer windings. This is performed with a one single-step cable setup, with test currents of up to 25 A. Each transformer configuration has a special measurement algorithm which is optimized for the fast stabilization of test results.



  • Six-winding resistance measurement
  • DC test current 5 mA – 25 A
  • Measurement accuracy ± (0,1 % rdg + 0,1 % FS)
  • DVtest sampling resolution 4 ms
  • 3-phase demagnetization
  • Interchangeable test leads with TRT turns ratio testers
  • USB flash drive feature
  • Built-in tap changer control unit