AS 62271 301 pdf download – High voltage switchgear and controlgear Part 301: Dimensional standardization of terminals
4 DIMENSIONAL REQUIREMENTS4.1General
Terminals shall comply with the details and dimensions shown in Figures 1 to 3 and ‘Tablesl and 2 as appropriate, and with the requirements given in Clauses 4.2 to 4.4.
4.2 Surface areas of terminals
The current carrying surface(s) of terminals shall be flat or cylindrical as applicable,freefrom blemishes and with a surface roughness as defined in AS 1100.201 not greater than3.2 um.
The contact and rear surface areas of palm terminals shall be parallel. If the rear surface isrequired as a current-carrying surface, this shall be specified by the purchaser.
4.3 Thickness of palm terminals
The palm terminal thicknesses given in Table 1 are considered to be minimum practicalvalues for the current ratings nominated and for normal mechanical loading.Where specialconditions apply，such as abnormal mechanical loading, the thickness shall be as specifiedby the purchaser, or where applicable shall be subject to their approval.
4.4Space orientation of major and minor axes of palm terminals
The space orientation of the major and minor axes of equipment palm terminals shall be asspecified by the purchaser.
5 ALTERNATING CURRENT RATINGs
The current ratings assigned to the terminals in Figures 1 to 3 are those specified in thevarious Australian standards for electrical equipment, are in accordance with the R10 seriesof preferred numbers in AS 2752, and reflect common usage.
The assigned values for palm terminals may be exceeded provided that the current densityat the joint face, i.e.0.17 A/mm3for aluminium or 0.32 A/mm’ for copper,is not exceededand that the joint is designed and prepared in accordance with Appendix B.
NOTE: Palm terminals having current ratings exceeding 5000 A and cylindrical terminals havingcurrent ratings exceeding 3150 A are not covered by this standard and are a matter for agreementbetween purchaser and manufacturer.
The terminal may be made from any material acceptable to the purchaser.7TERMINALAPPLICATION
7.1Terminals with rectangular shape
The recommended dimensions for rectangular terminals should be restricted to thediameters of and the distances between the hole.
The dimensions are as follows:
(a)Hole diameters: 14 mm,16 mm, 1 8 mm, and 22 mm.
(b)Distance between holes: 40 mm,45 mm, 50 mm, 60 mm and 70 mm (centre-to-centre)Any possible combination of these dimensions is permitted.
The distance between holes should be applied to two adjacent holes, both along the abscissaand ordinate.
7.2 Palm terminals (See Figures 1 and 2)
All palm terminals except numbers 6 and ll may be used either as equipment palmterminals or as conductor palm terminals.Terminal number 7 is intended for use asconductor palm terminal with equipment palm terminal numbers 12,13 and 14.
Terminal numbers 6 and l l are intended for use as conductor palm terminals.7.3Cylindrical terminals (See Figure 3)
Where terminal numbers 15 to 20 are supplied on equipment，suitable adaptor palmterminals shall be provided by the equipment manufacturer if specified by the purchaser.