1. Wiring: Connect the instrument terminals (A, B, C, a, b, c) to the transformer terminals (A, B, C, a, b, c) accordingly. Be careful not to reverse the high and low voltage connections, as this may damage the instrument.
2. Turn on the power switch. The display will show self-test 1, self-test 2, self-test 3, and then "Pass", indicating that the instrument is performing self-tests. Finally, it will display the turns ratio, tap percentage, vector group, and the information display (error display) will show "Self-test passed", indicating that the instrument is normal and ready for the next step.
3. Press the
key to input the turns ratio, tap spacing, and vector group sequentially until the parameter indicator light turns off. If the parameters for this test are the same as the previous ones, this step can be omitted.
4. Use the tap adjustment keys to adjust the tap position. Each press of this key moves the tap value by one tap spacing. If pressing the tap adjustment key has no effect on the tap display, it means the tap spacing has not been set. In this case, press the Parameter key to set the tap spacing.
5. Measurement
a. Three-phase continuous: Press the key, the key light turns on. Press the key, the key light turns on, and the instrument begins measurement, automatically entering the recording state. After each phase is measured, a prompt tone sounds, and the instrument proceeds to the next phase. After all phases are completed, it stops automatically.
b. Single-phase: Press the key, the key light turns on. Press the key, the key light turns on, and the instrument begins measurement. After the error display stabilizes, record the data, then press the key, the key light turns on, completing the AB phase test. Similarly, complete the BC and CA phase measurements.
6. Printing
a. If printing is required, you must press the Record key before the measurement operation. The key light turns on, and the instrument enters the automatic recording state, automatically recording data from each subsequent measurement operation. If the power is cut off, and if you use the three-phase continuous function for measurement, the instrument automatically records, so there is no need to press the key before measurement.
b. Press the Print key, the screen displays "Printing", and after a moment, the screen displays "Print completed", indicating that printing is done. If any key is pressed during printing, the screen displays "Print aborted", and printing can be exited midway. If there is no data in memory, pressing the Print key will cause both the Print key light and the Record key light to flash, and the screen will display "Memory empty", indicating that printing is not possible.
c. Of course, if previous test data does not need to be retained, clear the data before the measurement operation. Press the key. If the memory is already empty, both the Clear Memory key light and the Record key light will flash, and the screen will display "Memory already empty". If the memory is not empty, the screen will display "Clear memory?", then press the Clear Memory key again to clear the memory, or press any other key to abort clearing, and the screen will display "Memory clear aborted". When the memory is full, the and key lights will flash as a prompt. Press the key twice consecutively to clear old data.
7. Use of Other Function Keys
a. key: If you need to observe the measured turns ratio during the measurement process, press the key before measurement. The key light turns on, indicating that the measured turns ratio can be displayed during measurement. Press the key again, the key light turns off, and the measured turns ratio will not be displayed during measurement.
b. key: Most transformers have taps on the high voltage side. When testing transformers with taps on the low voltage side, use this key. The key light turns on. Press this key again, the key light turns off. In most cases, this key light should be off.
c. key: If the vector group of a three-phase transformer is not known in advance, connect the three-phase transformer test leads, press the key, the key light turns on. Press the key, and the instrument begins working. It takes about 70 seconds, and the vector group and turns ratio test results will be displayed. The instrument does not analyze single-phase transformer vector groups; they are only 0 or 6. If the polarity is incorrect, the vector group display window will flash to indicate an error. Some transformers may show errors during vector group analysis, but can measure normally with input parameters. The reason is that the symmetry of the transformer core lamination is poor, and when one column is excited, the magnetic distribution error in other columns is large.
d. key: Press the key, and the instrument begins self-testing. First, it sequentially lights up all displays for the operator to check, then it checks whether the voltage divider and measurement circuit are working properly.
e. Number keys: The number keys are multifunctional keys, effective when the key light is on. For example, when the number "0" is pressed while the Parameter key light is on, pressing the key inputs 0. If the Parameter key light is off, pressing the key prints.
