Before using the tester, it is necessary to check the integrity of the DC high-voltage generator. The connecting cables should have no open circuits or short circuits, and the equipment should be free from any damages such as cracks.
2. Place the chassis and the voltage booster cylinder in the appropriate positions, and properly connect the power lines, cable lines and grounding wires. The protective grounding wire, the working grounding wire, and the grounding wire of the discharge rod should all be separately connected to the ground wire of the test sample (i.e., single-point grounding). It is strictly prohibited to connect the grounding wires in series with each other. Therefore, special grounding wires for DHV should be used.
3. The power switch should be in the off position and the voltage regulating potentiometer should be at zero. The overvoltage protection setting value is generally 1.1 times the test voltage.
4. Verify the sensitivity of the overvoltage protection setting during no-load voltage rise testing.
5. Switch on the power switch. At this point, the red light will come on, indicating that the power is connected.
6. Press the green button, and the green light will come on, indicating that the high voltage is connected.
7. Gradually adjust the pressure regulating potentiometer in a clockwise direction. The output terminal will start to increase the voltage from zero. Once the desired voltage is reached, record the current meter reading at the specified time, and check for any abnormal phenomena or sounds in the control box and the high-voltage output line.
8. Reduce the pressure. After returning the pressure regulating potentiometer to zero, immediately press the red button to cut off the high voltage and turn off the power switch.
9. Conduct leakage and DC withstand voltage tests on the sample. After confirming that there are no abnormal conditions in the test equipment through the inspection test, the leakage and DC withstand voltage tests on the sample can be carried out. Connect the sample and the ground wire properly, and after checking for no errors, turn on the power.
10. Increase the voltage or current to the desired level. The voltage increase speed should be 3-5 kV per second. For large-capacitance test samples, it is also necessary to monitor that the charging current of the ammeter does not exceed the maximum charging current of the test device. For small-capacitance test samples such as zinc oxide arresters and magnetic blowout arresters, first increase to 95% of the desired voltage (current), then slowly and carefully increase to the desired voltage (current). Then read the voltage (current) value from the digital display meter.
When conducting the 0.75UDC-1mA measurement on the zinc oxide arrester, first raise the voltage to the UDC1mA level, then press the yellow button. At this point, the voltage will drop to 75% of its original value and remain in this state. At this time, the current can be read. After the measurement is completed, turn the voltage regulating potentiometer counterclockwise back to zero and press the green button. To increase the voltage again, press the red button. If necessary, use an external high-voltage divider to compare the voltage on the control box.
11. After the test is completed, reduce the pressure and turn off the power supply.
12. Operations after the protection action
During use, if the green light goes out and the red light comes on, and the voltage drops, it indicates that the relevant protection has been activated. At this point, the power switch should be turned off. The indicator lights on the panel will not light up. The voltage regulating potentiometer should be returned to the zero position. After one minute, when the low-voltage capacitors in the standby system have fully discharged, the power switch can be turned on again.
Post time: Feb-28-2026