Transformer DC resistance tester operation method and wiring method

First, the operating mode and wiring method of transformer DC resistance tester:

This machine has five buttons: "reset", "print", "move", "discharge" and "determine".

1, resistance measurement:

After the transformer DC resistance tester is turned on or presses the reset button, it enters the initial state (1). Press "Move" key to move "↑" cursor pointer arrow back and forth to select the desired function, so that "↑" key points to "Ω", press "OK" key to enter the state of automatic resistance measurement (2), display resistance value (3) . Press the "Print" button once to print the measurement results. After the test is completed, press the "Discharge" button and the instrument will automatically discharge (4).


The current loop should be connected with the thick wire in the test wire, and the voltage loop should be connected with the thin wire in the test wire. (This instrument is equipped with a set of 4 x 8m test leads)

1. The measurement wiring for a single resistor is shown in the figure below. RX is the measured resistance.

2. When the measuring resistance is greater than "2Ω", select the constant current to test, press the "Move" button to move the indicator arrow "↑" to the right, select "A", press the confirmation button, press the "Print" button to increase, press "Move" button decreases. Can use this formula I = 10 / Ω to roughly estimate the current, select the appropriate current, in order to improve the measurement accuracy, press the confirmation key to display the loop current, and then press the confirmation key to test. After the resistance value is displayed, printing and discharging operations can be performed.

Second, the transformer DC resistance tester instrument features:

1. Fast measurement speed: The instrument outputs a maximum of 10A constant current, which can effectively compensate the current inertia of large inductance equipment and accelerate the saturation of core, thus shortening the charging time and improving the measurement speed. The bridge is hundreds of times faster.

2. High accuracy: This instrument uses the advanced high-power and high-precision program-controlled constant voltage and constant current technology of the single-chip microcomputer, which makes the charging current of the inductive load maintain a relatively stable value, the anti-induction ability is stable, and the anti-interference ability is strong. Guaranteed measurement accuracy.

3. The instrument has a high degree of intelligence, compact structure and reasonable layout. In addition to adopting advanced four-terminal measurement method, it also adopts dual-path control comparison analysis, auto-zero calibration, anti-pull arc and data analysis circuit, automatic output print measurement data, menu operation, human-machine dialogue, operation reading extremely Convenient and quick.

Third, the use of matters needing attention:

1. It is forbidden to disassemble directly during measurement. After the wiring tester is finished, it is forbidden to directly press the reset button and forcefully turn off the power.

2. During the measurement process or after the measurement is completed, press the back key “←” or save the keyboard “→” to discharge the test object. After the discharge is completed, the connection cable can be removed.

3. During power failure maintenance of the transformer during operation, the high voltage side must be grounded for safety reasons, but when measuring the transformer windings, the connection between the winding and the ground should be removed, otherwise the measurement time will be prolonged.

4. When the special fixture is clamped on the winding end of the transformer, the transformer DC resistance tester should remove the oil contamination and the oxide layer, and should be clamped on the part directly connected to the winding, and do not cause measurement errors through screws.

5. In order to ensure the stability of the measurement figures, the AC220V voltage provided by the on-site instrument should be “one phase and one zero” instead of “one phase, one ground,” otherwise the liquid crystal display will jump more.

6. When measuring the low-voltage side of the transformer, all personnel should maintain a proper safety distance from the high-voltage side.

7. The instrument should avoid strong vibration, direct sunlight and magnetic field during transportation, storage and work. When storing and keeping the instrument, attention should be paid to the ambient temperature and humidity. It should be suitable for dry, ventilated, non-corrosive gas. When exposed to moisture, rain, or sun exposure, use it gently and gently. Do not drop it.

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