1. Wiring: Connect the instrument terminals (A, B, C, a, b, c) to the transformer terminals (A, B, C, a, b, c) correspondingly. 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 transformation ratio, tap percentage, group, and the information display bar (error display bar) will show "Self-test passed", indicating the instrument is normal and ready for the next step.

3. Press the key to input the transformation ratio, tap spacing, and group in sequence until the parameter indicator light goes out. 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 spacing. If pressing the tap adjustment key has no response 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 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, 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" to finish printing. If any key is pressed 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 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, 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?", then press the clear memory key again to clear the memory, or press any other key to abort clearing, 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. Use of Other Function Keys

a. key: If you need to observe the measured ratio during measurement, press the key before measurement. The key light turns on, indicating that the measured ratio can be displayed during measurement. Press the key again, the key light turns off, and the measured 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 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 group and ratio test results will be displayed. The instrument does not analyze single-phase transformer groups; it is only 0 or 6. If the polarity is wrong, the group display window flashes to indicate an error. Some transformers may show errors when analyzing the group, 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 lights up all displays in sequence 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.