The DC resistance fast tester is a high-precision replacement product that replaces the DC single and double-arm bridges. The DC resistance test of the transformer winding is an indispensable test item after the transformer is handed over, overhauled, and changed the tap switch. By measuring the DC resistance of the transformer windings, you can check the welding or connection quality of the leads, whether the windings are short-circuited or open, and whether the tap switch is in good contact. In the past, the measurement of direct resistance was measured by QJ44 double-arm bridge, and the measurement current of this type of bridge is milliampere, which takes a long time to measure, and the accuracy is also low. In order to change this situation, shorten the measurement time and reduce the workload of testers, thus developed a rapid DC resistance tester.

How to use the DC resistance fast tester:

When measuring each phase winding of the same voltage level of the same transformer, the same current should be selected for measurement to avoid causing system errors. The larger the transformer capacity, the smaller the resistance of the winding, and the larger the selected test current. Note that the measurement range of the selected test current must be greater than the actual resistance value. The test starts after pressing the "Measure" key. At this time, the screen appears "charging.", and there is a charging progress bar to show the charging progress. After the charging is finished, the screen prompts "Please wait while the measurement is being performed", and the display area in the middle of the screen displays the measured resistance value. After the reading is stable, read the value, and then press the "storage" key to store the measured data or press the "print" key to print the data as needed.

If the measured resistance is out of the range that can be measured in the current range, the screen prompts "over range". At this time, press the "Exit" key to exit the measurement, and then reselect the test current and try again.

End measurement:

After testing a tap on the no-load tapping transformer, you need to press the "Exit" key of the instrument, wait for the discharge instruction to finish, and then adjust the tap switch for the next measurement.

For the on-load tapping transformer, after measuring a tap, there is no need to discharge it. After directly adjusting the on-load tapping switch, press the “re-test” key of the instrument, and the instrument will perform the next tap measurement, which greatly shortens the measurement time. .

After the measurement is over (please refer to the "Data Storage and Printing" chapter for storing data or printing data), press the "Exit" key. The machine turns off the output and returns to the initial state. Wait for the next measurement. If it is an inductive load, it will enter the discharge state, and the discharge information will be displayed on the screen at this time. After the discharge is completed, return to the measurement menu and wait for the next measurement. The discharge time depends on the inductance of the tested product.

Note: After measuring the inductive load, the test line cannot be directly removed, so as not to endanger the safety of testers and equipment due to inductive discharge. The output terminal of this machine is equipped with a discharge circuit. When the output is turned off, the inductor will discharge energy through it. The test line must be removed after the discharge instruction is completed.