\u201cDielectric Strength\u201d<\/i> is an engineering term that describes the maximum voltage that insulating oil can withstand without damage or interference. \u00a0Dielectric strength is the main characteristic of liquid insulating oils and is one of the main criteria for the testing of new oils on reliability and suitability for use in electric power transformers.<\/p>\n
Reduced operational capability of transformer oils is a major cause of accidents and catastrophic transformer failures. \u00a0That is why oil must be monitored and cleaned and purified before it becomes harmful to the transformer core and solid insulation.<\/p>\n
Before using and installing insulating oil, it is important to establish the parameters of the dielectric strength necessary to properly protect the transformer. \u00a0Additionally, it is important to establish a preventive maintenance program that best meets the needs of the electric power equipment.<\/p>\n
Indicators are computed by exposure to high voltage insulation in a specially equipped medium which can be used to measure the potential electrical breakdown.<\/p>\n
\u201cDielectric Breakdown\u201d is the indication of a transformer insulating oil\u2019s ability to withstand electrical load. \u00a0The international test standard for dielectric strength is found in the American Society for Testing and Materials (ASTM) standard D-877.<\/p>\n
The test for dielectric strength of is quite simple to perform and the results are very easy to use as a reference value in the comparison of data from multiple test and trials. \u00a0The voltage used to check the dielectric strength of the transformer insulating oil typically ranges from between 5,000 and 400,000 volts (5-400 kv).<\/p>\n
A sample of transformer oil is placed in a cleaned container for testing. \u00a0In the same vessel, usually at the bottom of the vessel, \u00a0two flat electrodes are placed at a distance of 2.5 mm (sometimes 4 mm, for checking the operation oils in certain types of transformers) from each other. \u00a0The two electrodes are slowly charged with electricity with the voltage gradually rising. \u00a0Eventually a spark will jump between the two electrodes as the voltage is increased. \u00a0This test is repeated between three and six times and an average voltage of the testing is used to arrive at the actual \u201cBreakdown Voltage\u201d number. \u00a0This number indicates the voltage level at which the oil will breakdown and conduct electricity. \u00a0Once the oil becomes a conductor of electricity, it can no longer function as an insulator for the transformer\u2019s core and windings.<\/p>\n
Testing to determine the dielectric strength of transformer insulating oil is the most important test because dielectric strength is the one performance characteristic that determines the operating ability of the liquid insulation. \u00a0Dielectric strength must be high enough to protect the solid insulation and ensure the safe operation of the transformer.<\/p>\n
New or recently purified transformer oil that is clean will yield higher test results than used oils that contain moisture and mechanical impurities. \u00a0The Minimum breakdown voltage for transformer insulating oil (dielectric strength) that is considered safe is 30 kV.<\/p>\n
There is a range of equipment on the market that utilize specialized testers that can check the value of the \u201cBreakdown Voltage\u201d number taken from of transformer oil samples.<\/p>\n","protected":false},"excerpt":{"rendered":"
\u201cDielectric Strength\u201d is an engineering term that describes the maximum voltage that insulating oil can withstand without damage or interference. \u00a0Dielectric strength is the main characteristic of liquid insulating oils and is one of the main criteria for the testing of new oils on reliability and suitability for use in electric power transformers. Reduced operationalRead More <\/a><\/p>\n","protected":false},"author":7,"featured_media":2114,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[],"class_list":["post-1953","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-case_studies"],"acf":[],"language":"en","_links":{"self":[{"href":"https:\/\/oilregeneration.globecore.com\/en\/wp-json\/wp\/v2\/posts\/1953","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/oilregeneration.globecore.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/oilregeneration.globecore.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/oilregeneration.globecore.com\/en\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/oilregeneration.globecore.com\/en\/wp-json\/wp\/v2\/comments?post=1953"}],"version-history":[{"count":0,"href":"https:\/\/oilregeneration.globecore.com\/en\/wp-json\/wp\/v2\/posts\/1953\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/oilregeneration.globecore.com\/en\/wp-json\/wp\/v2\/media\/2114"}],"wp:attachment":[{"href":"https:\/\/oilregeneration.globecore.com\/en\/wp-json\/wp\/v2\/media?parent=1953"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/oilregeneration.globecore.com\/en\/wp-json\/wp\/v2\/categories?post=1953"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/oilregeneration.globecore.com\/en\/wp-json\/wp\/v2\/tags?post=1953"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}