IEEE 21-1976 pdf download.IEEE General Requirements and Test Procedure for Outdoor Apparatus Bushings.
1.1 Scope. This standard applies to outdoor power class apparatus bushings which have basic impulse insulation levels of 110 kV and above for use as components of oil-filled trans formers, oil-filled reactors, and oil circuit breakers.
1.2 Purpose. This standard defines the special terms used, service conditions, rating, general requirements, and test procedure. See IEEE Std 24-1976. Electrical. Dimensional, and Re- lated Requirements for Outdoor Apparatus Bushings (ANSI C76.2-1976)， for specific listings of values of electrical and mechanical char acteristics. dimensions, and other related test and quality control requirements which are de scribed in this standard.
7. Test Procedure
This test procedure summarizes the variou tests which are made on power apparatus bushings, describes accepted methods used in making the tests, and specifies the tests which will demonstrate ratings in this standard. It does not preclude the use of other equivalent or more effective methods of demonstrating ratings. These tests are divided into the following classifications:
(1)Design tests
(2)Production tests
7.1 Preparation of Bushings for Tests. The test specimen shall comply with the following re quirements.
(1)Except for mechanical tests, bushings shall be mounted on a supporting structure and in the position approximating that for which they were designed and with their ends in media of the type in which they are intended to operate.
(2)Bushings shall be completely assembled with all elements normally considered essential parts of the bushings.IEEE 21-1976 pdf download.