Darui Electric recommends
★★★ Precautions
1. The secondary winding of the current transformer should not have a grounding point.
2. Wiring and unwiring can only be done when the voltage regulator switch and output switch are in the off position.
3. The device should be reliably grounded before testing.
4. After completing the test, return to zero promptly. It is strictly forbidden to stay under high voltage and high current for a long time.
III. Panel Diagram and Description (Figure 1)
1——Voltage acquisition input terminal, connects to the remote end of AC output and the secondary side of CT.
2——AC current output, connects to the secondary side of CT.
3——Voltage regulator output fuse (15A).
4——Voltage regulator output switch.
5——Voltage boosting adjustment handle.
6——Four-digit LCD screen for current display (V) [also serves as CT secondary current display for ratio test].
7——Four-digit LCD screen for current display (A) [also serves as CT primary current display for ratio test].
8——Printer.
9——Data reset button.
10——Data storage button.
11——Print button.
12——Reset indicator light.
13——Storage indicator light.
14——Ratio current input, connects to CT secondary side.
15——Ratio current output, connects to CT primary side.
16——Switch for volt-ampere characteristic test and ratio test.
17——Polarity discrimination input, connects to CT secondary side.
18——Polarity discrimination output, connects to CT primary side.
19——Polarity discrimination current display meter, zero when not testing.
20——Polarity discrimination on/off button, press to turn on, release to turn off.
21——Grounding socket.
22——Main unit fuse (1A).
23——Power socket.
24——Main power switch.
25——External sensor interface, external primary current input terminal.
I. Technical Parameters
1. Input voltage: AC 220V or 380V, 50HZ, automatic identification of input voltage.
2. Operating ambient temperature: 0~40℃.
3. Input voltage: When input AC 220V, output 0-500V.
When input AC 380V, output 0-1000V.
Current: Maximum instantaneous current is 600A when testing ratio.
When input AC 220V, output 0-400A.
When input AC 380V, output 0-600A.
15A for volt-ampere characteristic test.
4. Digital voltmeter measurement range: 0-9999V; resolution: 0.1V.
When used as current display: 0-9.9A; resolution: 0.1mA.
5. Digital ammeter measurement range: 0~3000A; resolution: 0.01A.
6. Error: 1≤1%, U≤1%.
7. When testing CT ratio, the ratio value can be automatically calculated, and data and calculation results can be printed.
8. When testing volt-ampere characteristics, 20 sets of current and voltage values and the volt-ampere characteristic curve can be stored and printed.
9. Dimensions: Length × Width × Height = 470 × 340 × 260mm³.
10. Weight: 23Kg.
IV. Usage Method
● Volt-Ampere Characteristic Test:
Wiring is as shown below: (Figure 2)
1. The user should appropriately select the input voltage based on the volt-ampere characteristics of the device under test. When output voltage above 500V is required, input 380V.
2. Ground the instrument reliably.
3. Check that the current transformer has no grounding point.
4. Set switch "16" to the volt-ampere position.
5. Connect the instrument output and voltage measurement to the secondary side of the current transformer (as shown in Figure 2).
6. Check that the voltage regulator is at zero, turn on switch "24", press the reset button once, the indicator light above it will light up, and the microprocessor is in a waiting storage state.
7. Turn on output switch 4, slowly rotate the voltage regulator clockwise. When storage is needed, press the storage button once, the indicator light above the storage button will light up, and the internal buzzer will sound. (Note: During the entire measurement process, the voltage regulator must not be turned back. The dwell time at high current should be as short as possible.)
8. Up to 20 sets of current and voltage values can be stored.
9. After storage, return the voltage regulator to zero.
10. Press the print button to print the test data and volt-ampere characteristic dot matrix diagram. The voltage axis has three ranges, selected automatically based on the maximum sampled voltage:
0—199V each grid represents 10V
200V—499V each grid represents 25V
500V—2000V each grid represents 50V
The current axis has two ranges, selected automatically based on the maximum sampled current.
0—7A each grid represents 0.25A
7A—40A each grid represents 0.5A
11. After pressing the reset button to reset, the test can be repeated.
12. After the test, turn off switch "4" and switch "24", and unplug the connecting wires.
V. Ratio Test: Wiring is as shown below (left side): (Figure 3)
1. Set switch "16" to the ratio position.
2. When input AC 220V, output 0-400A;
When input AC 380V, output 0-600A.
3. Turn knob "5" to zero, turn on switch "24", then turn on switch "4", slowly rotate knob "5" so that meter "7" displays a current value `IO (A), and meter "6" has a corresponding current value Ii (mA). After the display stabilizes, press the storage button "10" to store the data.
Turn knob "5" to zero, press key "11" to print the ratio data and calculation results. Turn off switch "4".
4. After the test, disconnect the power and unplug the connecting wires.
5. When the primary current for ratio test is insufficient, an external current booster can be used. The external sensor provided with the instrument should be passed through the power cord of the current booster and then connected to the external primary socket 25. The secondary wiring should still be connected to the secondary socket. During the test, do not turn on switch 4 (the voltage regulator switch).
6. Note: ① Only one set of ratio test can be performed and calculated at a time. To repeat the ratio test, reset switch "16" forward and then switch back to the ratio position. The ratio test is automatically limited to about half a minute.
② The calculated ratio result is approximately an integer "XXX", i.e., "XXX:1". Users can convert it to "XXX:5" or other ratios based on their CT.
Note: The above information and technical parameters are compiled and published by Yangzhou Darui Electric Co., Ltd.
