Switching Surge Tests for Oil-Insulated Power Transformers

A draft of proposed standards for switching surge tests on oil-insulated power transformers is presented for study and information. A brief review of the background leading to such tests is followed by the proposed standard dealing with switching surge test specifications, the test code which includes wave shape requirements, suggested methods of generating switching surge transients, sequence of tests, failure detection, core saturation, and test connections. A table of switching surge test voltage corresponding to basic impulse insulation level is presented for oil-immersed apparatus to be used when switching surge tests are specified.