in the EPTTR-IV ?

General Information:
EPTTR-IV Automatic Transformer Turns Ratio Tester is suitable for measurements of transformer variable ratio phase, such as, power transformers, phase-shift rectifier transformers, Scott transformers, reverse Scott transformers, etc.
The internal power module in the tester generates the three-phase power or two-phase power, which is output to the high voltage side of the transformer. Then the high voltage and low voltage are sampled at the same time. Finally, the group, ratio, error and phase difference are calculated.

--The tester automatically generates a stable 3-phase or 2-phase voltage, which is directly applied to the high-voltage side. It is not constrained by the internal wiring of the transformer and is suitable for measurement of the transformer voltage ratio of various connection methods.

--The tester outputs 2 test voltages, which enhances the adaptability of the voltage ratio test for transformers with different voltage levels.

--Increase the test function of the low-voltage turns per coil.

--The current ratio of the current transformer can be measured.

--For the transformer with the tap switch, after parameters are set, when measuring, the tester automatically determines the position of tap switch and the standard voltage ratio of the current position, that is, tap voltage ratio.

--Three-phase simultaneous measurement is realized in real sense, and the testing time of a set of data is 10 seconds.

--The tester is powered by a 12V lithium battery and automatically generates a three-phase (120°) or two-phase (90°) power supply with stable amplitude and constant phase. It is not affected by the AC power supply, the repeatability of the test data is good.

--The output voltage of the tester is from 0V, overvoltage automatically resets, and the output is cut off.

--Reverse connection protection function.

--Output over-current, overheat, and automatically cut off the output.

--7-inch TFT touch screen, which is intuitive and convenient.

--2 USB ports. One is for online, after online, the measurement can be controlled by the PC, and the uploaded data is saved to the EXCEL file; another USB interface is used to insert a U disk to save the data. There are two saved files: One is for reading and printing, and the other is used to import EXCEL.

--The user’s manual is built-in in the tester, and it can be consulted at any time.

Technical Specifications:

Voltage ratio test range


Group test range:


Voltage ratio test accuracy

1500: 0.1% High voltage

5002000: 0.2% High voltage

200010000: 0.5% High voltage

1100: 0.2% Low voltage

100500: 0.5% Low voltage

Voltage ratio resolution:


Angle accuracy:


Angle resolution:


Accuracy of current measurement:

1% FS + 2 characters

Power Input

Lithium battery 12V 10Ah





Operating temperature:


Relative humidity

≤90%No dew