Winding Resistance Meters |  Detailed introduction of technical principles

The core principle of a transformer winding resistance tester is the DC voltage drop method. A constant DC current is injected into the winding, and the DC resistance is calculated based on Ohm's law (R=U/I) by precisely measuring the voltage drop across the winding.

Due to the extremely high inductance of the winding, the instrument employs a "constant current-sampling" operating mode: first, a constant DC current (typically several to hundreds of amperes) is output to charge the winding. Once the current stabilizes and the inductive effect is largely eliminated, the instrument simultaneously and rapidly acquires the current (I) and the voltage (U) across the winding. The DC resistance of the winding under the test current can then be precisely calculated.

This test is one of the most fundamental and important tests for transformers. By measuring the DC resistance of each phase winding and comparing the unbalance rate between the three phases, as well as the deviations from factory data and historical data, defects such as poor welding of internal winding wires, loose lead connections, tap changer contact faults, and inter-turn short circuits can be effectively diagnosed. Transformer Winding Resistance Tester, Transformer Winding Resistance Ohmmeter, Transformer Winding Resistance Tester 5mA-20A

1. The instrument offers 6 output current settings, with a maximum current of 20A and a minimum current of <5mA, suitable for measuring the DC resistance of various types of transformers and instrument transformers.

2. The instrument has a wide measurement range (from 100μΩ to 100KΩ).

3. Faster response speed; it can directly switch to on-load tap changer during measurement, and the instrument automatically refreshes the data.

4. The instrument has an audible discharge alarm function, with clear discharge indication, reducing accidental operation.

5. Comprehensive protection functions reliably protect the instrument from back EMF impacts, ensuring more reliable performance.

6. The instrument uses a 7-inch color LCD screen with a clear and aesthetically pleasing interface, and can print out results in real time.

7. The instrument can be configured with both English and Chinese operating interfaces, and can be customized according to customer needs.

1. Output Current: 20A, 10A, 5A, 2A, 100mA, <5mA (six testing ranges)

2. Measuring Range: 100μΩ-1Ω (20A), 500μΩ-2Ω (10A), 1mΩ-4Ω (5A), 5mΩ-10Ω (2A), 100mΩ-200Ω (100mA), 200Ω-100kΩ (<5mA)

3. Accuracy: 0.2%±2μΩ

4. Resolution: 0.1μΩ

5. Operating Temperature: 0-40℃

6. Ambient Humidity: ≤90%RH (non-condensing)

7. Altitude: ≤1000 meters

8. Power Supply: AC220V±10% 50Hz±1Hz

DC Resistance Tester, Winding Resistance Tester, Transformer Winding Resistance Tester, Transformer DC Resistance Tester, DC Winding Resistance Test Kit

MS-520 Winding Resistance Tester, Transformer Winding Resistance Ohmmeter, Transformer Winding Resistance Tester