6 and 8.7 are the design voltages between the cable conductor and the shielding layer.
The DC withstand voltage test of 10kV cable is 40kV.
The DC withstand voltage test of the cable is 4 times the rated voltage, and the time is 65438 0 minutes. AC power frequency withstand voltage test belongs to destructive test, the voltage is 2.5 times the rated voltage, and the time is 1 min.
1. Breakdown test is one of the main methods to test the overvoltage tolerance of electrical appliances, electrical equipment, electrical devices, electrical circuits and electrical safety appliances. Frequency division withstand voltage test and DC withstand voltage test.
2. Power frequency withstand voltage test: the test voltage is one to several times of the rated voltage of the tested equipment, and not less than 1 000 v ... Its pressurization time: porcelain and liquid-based insulation equipment1minute, organic solid-based insulation equipment for 5 minutes, voltage transformer for 3 minutes, and oil-immersed power cable1minute.
3.DC withstand voltage test can draw the leakage current-voltage characteristic curve through the leakage current value under different test voltages. Electrical equipment can find local defects, moisture and aging of insulation through withstand voltage test.
Extended data:
The DC high voltage generator adopts intermediate frequency voltage doubling circuit, and the new DC high voltage generator adopts PWM pulse width modulation technology and high power IGBT devices. According to the theory of electromagnetic compatibility, special shielding, isolation and grounding measures are adopted. The DC high voltage tester is of high quality and portable, and can withstand rated voltage discharge without damage.
DC high-voltage generator has many protection functions, such as low-voltage overcurrent, low-voltage overvoltage, high-voltage overcurrent, high-voltage overvoltage, zero protection and ungrounded protection. Intelligent DC high voltage generator adopts special sensor for fault sampling, the action time is nanosecond, and the optical isolation element is nanosecond. In general, the action time is 10 microsecond, which can completely turn off the DC main circuit.
Test purpose: to preliminarily judge whether the main insulation is aging due to moisture, and to check whether there is any defect in the cable main insulation after the withstand voltage test. The decrease of insulation resistance indicates that insulation is damp, aging and deterioration, which may lead to cable breakdown and burning. It can only effectively detect the overall moisture and penetration defects, and is insensitive to local defects.
Precautions:
1. DC withstand voltage test of electrical equipment can only be carried out after one person connects the wires and the other person checks and confirms that the wires are correct.
2. Microammeters used should be shielded during high-voltage wiring, with shielded wires for high-voltage leads and shielding covers for test cables.
3. When there is no special test device, a filter capacitor should be added to the test object with small capacitance.
4. In the half-wave rectifier device, it must be noted that the maximum working voltage of the rectifier tube shall not exceed half of the rated peak voltage.
5. Pay attention to the polarity of silicon tube when using silicon tube for voltage doubling rectification.
6. Micro-ammeters for high-voltage measurement should be equipped with protective devices, and the protective capacitors should be well insulated, and there should be no leakage.
7. Do the DC withstand voltage test of the cable and connect the protective resistor in the conductive loop. After the test, it should be discharged through resistance, and if necessary, the nearby equipment should be discharged or short-circuited in advance.
8. When conducting current test of lightning arrester, high voltage measurement should be adopted.
9. For equipment that can be carried out in stages, it must be carried out in stages, so as to compare and judge the test results of each stage.