BS 223:1985

Foreword
Committees responsible
Section one: General
Clause
1. Scope
Section two: Definitions
2. Definitions
Section three: Ratings
3. Standard values of nominal voltage (UN)
4. Standard values of rated current (IN)
5. Standard values of rated thermal short-time
     current (Ith)
6. Standard value of rated dynamic current (Id)
7. Minimum withstand values of cantilever load
8. Angle of mounting
9. Minimum nominal specific creepage distance
10. Temperature limits
11. Standard insulation levels
12. Maximum values of capacitance and dielectric
     dissipation factor of the test tap on transformer
     bushings
Section four: Information to be furnished when ordering
and markings
13. Enumeration of characteristics
14. Markings
Section five: Operating conditions
15. Temporary overvoltages
16. Altitude
17. Temperature of ambient air and immersion media
Section six: Test requirements
18. General
19. Test classification
20. Condition of the bushings during the dielectric
     and thermal tests
Section seven: Type tests
21. Wet power-frequency voltage withstand test
22. Dry lightning impulse voltage withstand test
23. Dry or wet switching impulse voltage withstand test
24. Thermal stability test
25. Temperature-rise test
26. Thermal short-time current withstand test
27. Dynamic current withstand test
28. Cantilever load withstand test
29. Tightness test on liquid-filled and liquid-
     insulated bushings
Section eight: Routine tests
30. Measurement of the dielectric dissipation factor
     (tan delta) and the capacitance at ambient
     temperature
31. Dry power-frequency voltage withstand test
32. Measurement of the partial discharge quantity
33. Tests of the tap insulation
34. Pressure test of gas-filled and gas-insulated
     bushings
35. Tightness test on liquid-filled and liquid-
     insulated bushings
36. Tightness test on gas-filled, gas-insulated and
     gas-immersed bushings
37. Tightness test at the flange or other fixing device
Tables
I. Standard insulation levels for nominal voltages
     lower than 300 kV
II. Standard insulation levels for nominal voltages
     equal to or higher than 300 kV
III. List of drypower-frequency withstand test voltages
     to be applied in the test according to clause 31
     for nominal voltages higher than or equal to 300 kV
Figure
1. Arrangement for thermal and dynamic current
     withstand tests according to clauses 26 and 27

Describes bushings, intended for use in electrical apparatus, transformers, and installations, for three-phase alternating current systems above 1000 V between 15 Hz and 60 Hz. Not applicable to bushings for use with rectifiers, rotating machines, testing transformers, or to terminals for power cables. Not applicable to insulating structures similar to bushings, which are used as support insulators inside metal-enclosed switchgear for voltages above 72.5 kV.