How to Select the DC Resistance Tester Correctly

Transformer DC resistance tester is divided into 1A, 3A, 5A, 10A, 20A, 40A, 50A, 100A and other specifications. The instrument power supply is divided into external power supply AC220V, internal power supply (battery power supply), AC and DC power supply. At present, DC resistance testers above 10A on the market are not battery powered.

Performance requirements, technical indicators and characteristic analysis of transformer DC resistance tester:

1. Current and voltage: In actual measurement, different test currents should be selected according to different items. When the current is too small, the measurement accuracy will be affected.

2. Measuring range: the DC resistance of general power transformer is between 100m Ω – 100 Ω, and the measuring range of high-power inductors and other equipment is between 100u Ω – 2K Ω

3. Measurement accuracy: the higher the better

4. Instrument functions: single-phase measurement and three-phase measurement, data storage and printing

In principle, the greater the transformer capacity, the greater the test current.

3-5A DC resistance tester is generally used for 10KV voltage level;

10A DC resistance tester is generally selected for 35kV voltage level;

20A DC resistance tester is generally used for 110kV voltage level;

40A DC resistance tester is usually used for 220kV voltage level.

Excessive current will lead to temperature rise of transformer, which will lead to inaccurate resistance test, and too small current will lead to low test accuracy.

The above is the introduction of KST Power on how to choose a DC resistance tester. If you have any other information you want to know, please contact us online or by phone. We have a professional technical manager who will serve you wholeheartedly.