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, otherwise the instrument may be damaged.

2. Turn on the power switch. The display will show self-test 1; self-test 2; self-test 3; passed, indicating the instrument is performing self-test. Finally, it will display the turns ratio, tap percentage, vector group, and the information display (error display) will show "Self-test passed", indicating the instrument is normal and ready for the next step.

3. Press the key to input the turns ratio, tap step, and vector group sequentially until the parameter indicator light turns off. If the parameters used for this test are the same as the previous ones, this step can be omitted.

4. Use the tap adjustment key to adjust the tap position. Each press of this key moves the tap value by one tap step. If pressing the tap adjustment key has no response on the tap display, it means the tap step has not been set. In this case, press the parameter key to set the tap step.

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 and automatically enters the recording state. After each phase is measured, a prompt tone sounds, and it 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. 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 records automatically, 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 complete" to finish printing. If you press any key during printing, the screen displays "Print aborted", allowing you to exit printing 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 displays "Memory empty", so printing cannot be performed.

c. Of course, if previous test data does not need to be retained, clear the data before measurement operations. Press the key. If the memory is already empty, the clear memory key light and record key light will flash simultaneously, and the screen displays "Memory already empty". If the memory is not empty, the screen displays "Clear memory?", and pressing the clear memory key again will clear the memory. If you press any other key, it will abort clearing memory, and the screen displays "Clear memory aborted". When the memory is full, the and key lights flash as a prompt. Press the key twice consecutively to clear old data.

7. Usage of Other Function Keys

a. key: If you need to observe the measured turns ratio during measurement, 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 unknown, connect the three-phase transformer test leads, press the key, the key light turns on. Press the key, the instrument begins working, and it takes about 70 seconds. 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 flashes to indicate an error. Some transformers may show errors during vector group analysis, but normal measurement with input parameters works. The reason is that the symmetry of the transformer core lamination is poor, and when one limb is excited, the magnetic distribution error in other limbs is large.

d. key: Press the key, the instrument starts self-test. 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. Numeric keys: The numeric keys are multi-function keys and are effective when the key light is on. For example, when the parameter key light is on, pressing the key with the number "0" inputs 0. When the parameter light is off, pressing the key prints.