I. Overview 

The DC resistance of the transformer is a mandatory test item for the semi-finished

products, finished product factory tests, installation, handover tests and preventive tests of the power sector in the manufacture of transformers, which can effectively find manufacturing defects such as material selection, welding, loose connection parts, lack of shares, broken wires and hidden dangers after operation of the transformer coil. In order to meet the needs of rapid measurement of dc resistance of transformers, We has developed a new generation of JYR series DC resistance testers by using its own technical advantages. The instrument adopts a new power supply technology, which is characterized by small size, light weight and large output current. It is a test instrument optimized for measuring the DC resistance of three-phase windings of large-capacity transformers. The three-phase winding DC resistance of the transformer can be tested simultaneously. For on-load voltage regulating transformers, there is no need to discharge, directly adjust the tap, the measurement time is one-third of the traditional single-phase measurement, which can greatly shorten the working time. The whole machine is controlled by a single-chip microcomputer, which automatically completes the functions of self-test, data processing, display, etc., and also has functions such as automatic discharge and discharge sound alarm indication. This instrument test data is stable, high precision, fast speed, good repeatability, is the best choice for on-site measurement of transformer DC resistance. 

II. Performance Characteristics 

1. Fixed current output (10mA-20A total 8 gears), automatic current output (0.03-20A

automatically set the optimal current according to the resistance value of the sample).

2. With a wide measuring range (0Ω-20K Ω), it can measure inductive DC resistance such as transformers and transformers.

3. It has the functions of single-channel measurement, YN three-phase simultaneous

measurement, YN three-phase compensation simultaneous measurement (including O-phase resistance), YND11 transformer automatic magnetization, YN three-phase phase selective measurement, D/Y three-phase phase selective measurement, and automatically calculates the three-phase resistance balance rate.

4. Assist in judging data stabilization function. Automatically calculates the percentage of

resistance deviation of 5", 15" or 30" to accurately determine the readability of data and

prevent misreading of data.

5. According to the temperature conversion function of the test material (copper, aluminum), it is convenient to compare with historical data.

6. It has the function of transformer demagnetization, which can effectively reduce the residual magnetism of the transformer.

7. With perpetual calendar, 100 sets of data storage, Chinese and English interface selection and other functions, shutdown does not lose data. There is also a micro printer, "USB stick" interface.

8. The monitor adopts a 6-inch color touch LCD screen.

9. Dual RS485 communication interface, convenient cascading between devices. With the host computer control software, to achieve long-distance control measurements, but also optionally installed built-in Bluetooth module, to achieve Bluetooth wireless communication.

10. With acoustic discharge alarm, the discharge indication is clear, reducing communication . 

11. With input misconnected AC380V power supply protection function, protect the rear audio alarm to reduce the damage to the instrument by misoperation, the instrument also has a perfect anti-potential protection function, strong anti-arc resistance.

12. It has the characteristics of dustproof, shockproof, moisture-proof, high measurement accuracy, good stability and repeatability, and easy to carry.

III. Specifications 

1. Output current:Auto、20A、10A、3A、1A、300m A、100mA 、30mA、10mA、

10mA 

2. Test Range:

Auto (30mA -20A) 0Ω - 600Ω         (3 phase measurement 0.001 Ω - 360Ω).

20A             0Ω – 1.0Ω         (3 phase measurement 0.001 Ω–0.6 Ω).

10A             0.001 Ω – 2.0Ω     (3 phase measurement 0.002 Ω–1.2Ω).

3A              0.003Ω – 6.0Ω      (3 phase measurement 0.006Ω–3.6Ω).

1A              0.01Ω – 20Ω       (3 phase measurement 0.02Ω – 12Ω).

300m A          0.03Ω – 60Ω       (3 phase measurement 0.06Ω - 36Ω).

100m A          0.1Ω – 200Ω       (3 phase measurement 0.2Ω - 120Ω).

30m A            0.5Ω – 600Ω       (3 phase measurement 1.0Ω - 360Ω).

10m A            20Ω – 20kΩ        (single phase test only).

3. Accuracy: 0.2% ±0. 2μΩ

4. Minimum resolution: 0.1 μΩ

5. Working temperature: -20~ 40 °C

6. Ambient humidity: ≤ 80%RH, no condensation

7. Power supply: AC: AC220V±10%, 50Hz±1Hz

8. Volume: Length 420mm× width 320mm× height 200mm

9. Net weight: 13.8kg