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How to select DC resistance tester?

:2022-08-11 13:37:45:

The transformer DC resistance tester is subdivided 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, the DC resistance testers above 10A on the market are not battery powered.

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

1. Current and voltage: in the actual measurement, different test currents shall be selected based on different subjects. When the current is too small, the measurement accuracy will be affected. The output voltage determines the speed of measuring the DC resistance of the transformer

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

3. Measurement accuracy: the higher the better

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

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

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

For 35kV voltage level, 10a DC resistance tester is generally selected;

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

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

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


KST-205a transformer DC resistance quick tester is a professional transformer DC resistance test equipment launched by our company * and is mainly used for DC resistance test of transformers in power system. The instrument adopts large screen LCD display, full Chinese menu, friendly human-machine interface, perfect function and convenient operation. It is an ideal instrument for DC resistance test of transformers in power system and transformer manufacturers.

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