BS 3297-2:1993

Committees responsible
National foreword
Foreword
Section one - General
1. Scope
2. Object
3. Electrical characteristics
4. Mechanical characteristics
5. Dimensional characteristics
6. Fixing arrangements
7. Plan of the standard
8. Designation of post insulators
Section two - Examples of insulator types
Figures
1. Example of an indoor post insulator of ceramic
     material or glass
2. Example of an indoor post insulator of organic
     material
3. Example of an outdoor cylindrical post insulator
     with internal metal fittings
4. Example of an outdoor cylindrical post insulator
     with external metal fittings
5. Example of an outdoor pedestal post insulator
Section three - Characteristics of standard post
insulators
Tables
I Indoor post insulators of ceramic material or glass
     and with internal metal fittings
IA Optional auxiliary holes in the top and/or bottom
     metal fitting
II Indoor post insulators of organic material and with
     internal metal fittings
IIA Optional auxiliary holes
III Outdoor cylindrical post insulators of ceramic
     material or glass and with internal metal fittings
IIIA Optional auxiliary holes in the top and/or bottom
     metal fittings
IV Outdoor cylindrical post insulators of ceramic
     material or glass and with external metal fittings
IVA Standard fixing arrangements of outdoor cylindrical
     post insulators with external metal fittings
V Outdoor pedestal post insulator units (metric units)
VA Standard fixing arrangements of pedestal post
     insulators
VI Outdoor pedestal post insulator units (inch-pound
     units)
VIA Standard fixing arrangements of pedestal post
     insulators
VII Outdoor pedestal post insulator units. Bending
     strength in stacks (metric units)
VIII Outdoor pedestal post insulator units. Bending
     strength in stacks (inch-pound units)
Appendix A -
Table AI - Examples of composition of outdoor pedestal
            post insulator (metric units)
Table AII - Examples of composition of outdoor pedestal
            post insulators
Annex ZA (normative) Other international publications
                     quoted in this standard with the
                     references to relevant European
                     publications
Annex ZB (normative) Special national conditions
National annex NA (informative) Cross-references

Establishes standard values of the electrical characteristics, dimensions and mechanical characteristics that are essential for the interchangeability of post insulators and post insulator units of the same type. Applies to post insulators and post insulator units of ceramic material or glass meant for outdoor and indoor service, and to post insulators of organic material in electrical installations or equipment operating on alternating current systems with a maximum frequency of 100 Hz and a nominal voltage over 1,000 V. Coverage includes: examples of insulator types; characteristics of standard post insulators. Also includes tables and annexes.

This standard applies to post insulators and post insulator units of ceramic material or glass intended for indoor or outdoor service, and to post insulators of organic material intended for indoor service in electrical installations or equipment operating on alternating current systems with a nominal voltage greater than 1 000 V and a frequency not greater than 100 Hz. It may also be regarded as a provisional standard for insulators for use on direct current systems. The insulators covered by this standard are primarily intended for use in isolators (disconnectors) or as bus-bar or fuse supports. This standard covers five types of post insulators: indoor post insulators of ceramic material or glass and with internal metal fittings; indoor post insulators of organic material and with internal metal fittings; outdoor cylindrical post insulators of ceramic material or glass and with internal metal fittings; outdoor cylindrical post insulators of ceramic material or glass and with external metal fittings; outdoor pedestal post insulators of ceramic material or glass. The term “cylindrical insulators” is intended to cover insulators of the truncated conical form also. The five types of insulators are distinguished by their electrical, mechanical and dimensional characteristics. Figure 1, Figure 2, Figure 3, Figure 4 and Figure 5 illustrate typical examples of each type of insulator. These drawings are only general illustrations and other shapes and constructions are permitted.