By hvhipot 
1. DC withstand voltage test
The DC withstand voltage test has a high voltage and plays a special role in detecting certain local insulation defects. It can be conducted simultaneously with the leakage current test.
Compared with AC withstand voltage test, DC withstand voltage test has the advantages of lightweight testing equipment, minimal insulation damage, and easy detection of local defects in the equipment. Compared with the AC withstand voltage test, the main disadvantage of the DC withstand voltage test is that the voltage distribution inside the insulation is different between AC and DC, and the DC withstand voltage test does not test the insulation as closely as the AC test.
Equipment selection: The ZGF series DC high voltage generator produced by HV Hipot Electric Co., Ltd. Power can be used for DC withstand voltage testing. During the DC withstand voltage test, the leakage current can be monitored using a MAS-II digital microampere meter.
2. AC voltage withstand test
The AC withstand voltage test is very strict in testing insulation and can effectively detect more dangerous concentrated defects. It is the most direct method for assessing the insulation strength of electrical equipment, and has a decisive significance in determining whether electrical equipment can be put into operation. It is also an important means to ensure the insulation level of equipment and avoid insulation accidents.
The AC withstand voltage test may sometimes exacerbate some weak points in the insulation. Therefore, before the test, it is necessary to conduct tests on the insulation resistance, absorption ratio, leakage current, and dielectric loss of the test sample. If the test results are qualified, the AC withstand voltage test can be carried out. Otherwise, it should be dealt with in a timely manner and the AC withstand voltage test should be conducted after all indicators are qualified to avoid unnecessary insulation damage.
Equipment selection: The YDJ series oil immersed test transformer produced by HV Hipot Electric Co., Ltd. Power can be used for AC withstand voltage testing. The BC2000 intelligent dual display insulation resistance tester can measure the insulation resistance of the test sample, as well as the absorption ratio and polarization index. The HTJS-V fully automatic anti-interference and abnormal frequency dielectric loss tester can measure the dielectric loss of the test sample.