Dielectric strength test of vacuum pressure switch

The dielectric strength test of vacuum pressure switches is an important link in evaluating their insulation performance, usually involving the following aspects:

Test purpose

Dielectric strength testing aims to measure the highest voltage that a vacuum pressure switch can withstand without being broken down within a specified period of time, in order to verify the tolerance of its insulating material or medium in an electric field.

Test equipment

The test equipment mainly includes high-voltage generators (AC or DC), breakdown voltage testers, test electrodes and protection devices, etc. The high-voltage generator is used to provide the test voltage, the breakdown voltage tester is used to record the voltage value at the time of breakdown, and the test electrode is used to apply voltage to the sample under test.

Test method

Preparation stage: Connect the conductive part of the sample to be tested to the high-voltage generator and ensure that the test environment meets the standard requirements, such as temperature and humidity.

Applied voltage: Gradually increase the voltage applied to the sample until the material breaks down. During the process of applying voltage, it is necessary to observe whether there is any breakdown, leakage or flashover phenomenon.

Record the result: Record the voltage value at the time of breakdown, which reflects the maximum withstand capacity of the material.

Test standards and evaluation

Dielectric strength is usually expressed in "volts per unit thickness" (such as V/mil or V/mm). The test results are expressed in terms of dielectric strength (breakdown voltage divided by insulation thickness), with the unit of kilovolts per millimeter (kV/mm). When conducting tests, relevant standards must be followed. For instance, standards such as IEC, UL, and GB have clear regulations on dielectric strength testing.

Precautions

Safe operation: During the testing process, safety operation procedures must be strictly followed to ensure the safety of personnel and equipment. For instance, operators should reserve a sufficient safe operating distance to avoid direct contact with high-voltage sections.

Equipment calibration: Before testing, the test equipment should be calibrated to ensure the accuracy of the test results.

Environmental control: The test environment should meet the standard requirements and avoid the influence of factors such as temperature and humidity on the test results.