This Standard covers the following; (1) Electrical requirements for outdoor power apparatus bushings having basic impulse insulation levels 110 through 1300 kilovolts. (2) Mechanical rccluiremcnts for the outdoor power apparatus bushings listed in Table 7.4 (3) Dimensions of the outdoor power transformer and alternating-current power circuit breaker apparatus bushings listed in Tables 7.1(a)@ 7.1(b). and 7.l(c). This Standard does not apply to bushings for indoor apparatus. dry type instrument transformers@ air-blast transformers. dry type regulators@ oil-less and oil-poor apparatus@ roof. Roar@ wall and generator bushings. potheads. distribution type circuit breakers and back-connected switch insulators. Bushing requirements as set forth in this Standard apply to bushings when mounted for testing. according to requirements outlined in Section 9.3.
IEEE 21-1964 history
1976IEEE 21-1976 GENERAL REQUIREMENTS AND TEST PROCEDURE FOR OUTDOOR APPARATUS BUSHINGS
1964IEEE 21-1964 Requirements and Test Code for OUTDOOR APPARATUS BUSHINGS (Includes ERRATA)
1942IEEE 21-1942 APPARATUS BUSHINGS AND TEST CODE FOR APPARATUS BUSHINGS
1941IEEE 21-1941 APPARATUS BUSHINGS and PROPOSED TEST CODE