Handheld transformer turns ratio tester (TTR)

  • Single- and three-phase transformer testing
  • Fully automatic, fast, easy-to-use, robust, lightweight
  • Battery powered (AA or LR-6)
  • Tests turns ratio, excitation current, and polarity
  • Simple, one-button operation
  • Ability to record via optional printer

The TTR20 handheld transformer turns ratio tester (TTR) is a robust, lightweight, and battery-operated instrument. It is used to measure the turns ratio, excitation current, and polarity of windings in single- and three-phase distribution and power transformers (tested phase-by-phase), as well as potential and current transformers (PTs and CTs), and tapped transformers. Deviations in these measurements will quickly indicate problems in transformer windings or in the magnetic core circuits.

The unique design of the TTR20 allows you to operate the test set while holding it in one hand. It effectively eliminates you having to kneel or bend down to operate the instrument and speeds up testing time. Realising the variety of harsh environments in which the TTR20 must operate, special attention has been paid to making it extra rugged and robust, with a high impact, shock-resistant case. Yet it is also incredibly lightweight at a mere 870 g (1.9 lbs). Additionally, it features a high contrast, backlit LCD screen which can be seen in bright or ambient light.

This unit measures a high turns ratio of 10 000:1 accurately with the lowest excitation voltage. The excellent repeatability of the TTR20 helps you to determine the condition of transformers under test. It is designed for simple, one-button operation with the measured results displayed directly on the easy-to-read LCD screen, or printed to the optional printer.

The TTR20 is particularly suited for testing in substations, transformer manufacturing environments, and meter shops. This type of TTR is best suited for power transformers up to 1 MVA. It it used to determine the no-load accuracy of PTs and CTs and also determine the need to further test faulty PTs and CTs. The TTR20 applies voltage to the high voltage winding of a transformer and accurately measures the resulting voltage from the low voltage winding. The ratio of voltages is directly proportional to turns ratio. In addition, the unit measures excitation current and polarity, needs no additional software, and comes ready to use out of the box.