1. Connection: Turn off the power switch of the instrument, and connect wires according to the following methods. Single-phase transformer Three-phase transformer Instrument Transformer Instrument Transformer A A A A B X B B C Not connected C C a a a a b x b b c Not connected c c The neutral point of the transformer is not connected to the instrument or to the ground. Connect the instrument's ground wire properly. Insert one end of the power cord into the power socket on the instrument panel, and connect the other end to an AC 220V power supply. Note: Do not reverse the high and low voltage connections of the transformer! Set connection method Set standard ratio Start data measurement View historical data ↑: Select Confirm: Execute 2. Turn on the power switch of the instrument. After a moment, the main menu appears on the LCD screen, as shown below. The selected menu is displayed in reverse (black background with white text). At this time, you can press the "↑" key to select the function menu, and press "Confirm" to execute the corresponding function. Note: Press and release the key for one key input. Set connection method Connection: Yy Set standard ratio Start data measurement View historical data ↑: Select Confirm: Save 3. Connection method setting: After entering the connection method setting, the LCD screen displays as follows. At this time, press the "↑" key to select the connection method, and press "Confirm" to save the connection method and return to the main menu. Set connection method Set standard ratio Ratio=25.000 Start measurement View historical data →: Shift ↑↓: Increase/Decrease Confirm: Save 4. Set standard ratio: After entering the standard ratio setting, the LCD screen displays as follows. At this time, press the "→" key to select the data digit, and the selected digit is displayed in reverse. Press the "↑" and "↓" keys to modify the data. After selecting a digit, pressing "↑" or "↓" cycles the digit from 0 to 9. If it is the first digit, it can only cycle from 1 to 9, and 0 will not appear. After selecting the decimal point, pressing "↑" or "↓" moves the decimal point cyclically. Set connection method Set standard ratio Tap ratio=0.00% Start measurement View historical data →: Shift ↑↓: Increase/Decrease Confirm: Save If the transformer has taps, the standard ratio set here is the standard ratio for the middle tap. After pressing "Confirm" to save the ratio, the LCD screen displays as follows. The setting method for the tap ratio is the same as that for the standard ratio. If the transformer has taps, set it according to the actual value; otherwise, set it to 0.00%. After pressing "Confirm" to save the tap ratio, return to the main menu. 5. After warming up for 5 minutes, select "Start data measurement" and press "Confirm". The display shows as follows. Connection=Yy? Ratio=25.000? →: No Confirm: Yes ↑↓: Change tap The ratio value displayed on the screen is the actual standard ratio needed for this measurement. You can press "↑" or "↓" to modify this value. Each modification step equals the set standard ratio multiplied by the tap ratio. After the measurement is completed, the display shows as follows. 3rd time Total 3 times Group: 12 o'clock AB: 25.008 0.03% BC: 25.010 0.04% CA: 25.000 0.00% ↑: Page up →: Print Confirm: Return After each measurement, the instrument automatically saves the data, up to 30 data sets. When more than 30, the current data is stored as the 30th, and the first data is cleared, i.e., first in, first out. The first line on the left shows the position of the current data in the historical data, and on the right shows the number of historical data sets. The second line is the group. The third line on the left is the ratio of phase AB, and on the right is the relative error of phase AB, and so on. If measuring a single-phase transformer, only the first three lines are displayed. If the relative error of the measured ratio is greater than 10%, display ">10%"; if less than -10%, display "<-10%". Press "↑" to view data. Press "←" to enter the print menu, where you can print the current data, print all data, or clear all historical data. Press "Confirm" to return to the main menu.
Precautions
1. Fuse 1 is 2A, fuse 2 is 0.5A. If the test leads are short-circuited or the high and low voltage connections are reversed, the fuse will blow. After the fuse blows, if a measurement is attempted, the display will stop after showing "Measuring, please wait!". Turn off the power, replace the fuse with the same rating, and retest. 2. Ensure good contact in the connections. The instrument should be properly grounded! 3. The working place of the instrument should be far from strong electric fields, strong magnetic fields, and high-frequency equipment. The power supply interference should be as small as possible. It is advisable to use lighting lines. If the power supply interference is still significant, an AC purified power supply can be used to power the instrument. The capacity of the AC purified power supply should be greater than 200VA. 4. During operation, if the LCD display is disordered, all keys are unresponsive, or the measured values differ greatly from the actual values, press the reset key or turn off the power and restart the operation. 5. If the display has no characters or the color is too light, adjust the brightness potentiometer to an appropriate position. The brightness potentiometer is a multi-turn potentiometer with 10 turns! 6. The instrument should be stored in a dry and ventilated place. If it is not used for a long time or the environment is humid, extend the warm-up time before use to remove moisture. 7. The communication port is used for debugging.
