I.Summary

At present, transformer DC resistance test and transformer ratio group test are the necessary items for transformer outage maintenance. To complete the above-mentioned test, transformer DC resistance tester and transformer ratio group tester need to be equipped separately. However, there are many manufacturers of the above two kinds of instruments, and their functions and wiring are different. In addition, two kinds of instruments are needed to be carried in each test, namely, transformer DC resistance tester and transformer ratio group tester. Because of the different functions of the two instruments, it is necessary to do two test preparations and two wiring and disconnection, which will greatly reduce the work efficiency. Transformer DC resistance ratio tester solves the above problems. One instrument can carry out two tests: direct resistance test and ratio test. The screen adopts large screen high-resolution LCD screen, which is convenient for field use, has menu prompt function, easy and intuitive operation, completes three-phase direct resistance test and three-phase ratio test at one time, and has fast test speed and high accuracy.

II.Technical Index

1. Main indicators of direct resistance:

DC resistance test current : AUTO , <20mA , 40mA , 200mA , 1A, 3A, 10A

DC resistance test range and accuracy: 10A: 0.5 mΩ ～ 800mΩ ±(0.2%+2 digits )

3 A : 2mΩ～ 2Ω ±(0.2%+2 digits)

: 5mΩ～ 10Ω ±(0.2%+2 digits)

200mA: 100mΩ～ 5 0Ω ±(0.2%+2 words)

40mA : 500mΩ～2 50Ω ±(0.2%+2 digits)

< 20 mA: 50Ω～ 50 KΩ ±(0.5%+2 digits)

Minimum resolution: 0.1μΩ

Display: LCD display   Resistor display has 4 effective figures

Data storage: 1000 groups

Working environment: relative humidity: <80%RH, non-condensing   Ambient temperature: -20 ℃ ~ 40 ℃

Power supply : AC 220V± 10 V, 50Hz± 1 Hz     Fuse 5 A

Maximum power consumption: 200W

2. Main indicators of transformation ratio:

1、 Test range: Transformation ratio -- 0.9 ~ 10000 Angle -- 0-360°

2、 Ratio accuracy: ± 0.1% + 2 words ( 0.9-500 )

± 0.2% + 2 words ( 501-20 0 0 _ _ )

  　    ± 0. 5 % + 2 words ( 2001-10 0 0 0 _ )

3. Angle accuracy: ± 0. 2°

4. Output voltage: automatically adjusted according to the load

5. Resolution: ratio - minimum 0.0001 , angle - 0.01°

6. Working power supply: AC220V ± 10%  50 ± 1Hz

7. Ambient temperature: - 10 ℃ ~ 40 ℃

8. Relative humidity: ≤ 85% , no condensation