BS 1432:1987 download.Specification for Copper for electrical purposes: high conductivity copper rectangular conductors with drawn or rolled edges.
1 Scope
BS 1432 specifies requirements for high conductivity copper conductors of rectangular cross section with drawn or rolled edges. It applies to conductors supplied:
a) in the grades of copper listed in Table 1; b) in the annealed, half-hard, hard and controlled proof stress conditions, the dimensions, and the corner and edge conditions given in Table 2;
c) in coils, or in cut lengths up to and including 6 m.
NOTE 1 Information to be supplied by the purchaser is given in Appendix A.
NOTE 2 Recommended dimensions and areas of bare rectangular copper conductors for various electrical applications are given in Table 9 and Table 10 in Appendix B.
NOTE 3 l’he titles of the publications referred to in BS 1432 are listed on the inside back cover.
2 Definitions
For the purposes of BS 1432 the following definitions apply.
drawn edges
the edges produced on a wrought rectangular product as a result of drawing it through a die
2.2
rolled edges
the edges produced on a wrought rectangular product as a result of edge (or side) rolling
5.2 Bend characteristics
Conductors supplied in the annealed, half-hard and hard condition shall be capable of being bent longitudinally through an angle of 180° round a former of radius as given in Table 3 without cracking. Conductors supplied in CPR1, CPR2 or CPR3 condition shall be capable of being bent longitudinally through an angle of 180° round a former of radius equal to the thickness of the conductor.
In addition, annealed conductors in widths up to and including 30 mm shall be capable of being bent, on edge, through an angle of 180° round a former of radius equal to half the width of the conductor without cracking.
NOTE For annealed conductors wider than 30 mm and for conductors in conditions other than annealed, an edgewise bend test requirement. possibly more severe than that given in 5.2. may be specified, subject to agreement between the purchaser and the supplier on the test requirements.
6 Electrical resistivity
The electrical resistivity in terms of volume resistivity at 20 °C, determined by measurement directly on the conductor, in accordance with Appendix G, shall not exceed the appropriate value given in Table 5.
NOTE Table 12 and Table 13 in Appendix D give the factors to be used for correcting resistance at various temperatures. Use of these tables enables a resistance measured at a temperature other than 20 °C to be converted to the resistance at 20 °C, in order to determine whether the conductor under test complies with the electrical resistivity requirements of this standard.
8.3 Straightness (edgewise curvature) of conductors
8.3.1 conductors in the half-hard and hard conditions in cut lengths. The edge of a conductor of cut length 2 m or over shall not vary by more than 10 mm from a straight line joining two points 2 m apart on that edge of the conductor. The edge of a conductor of cut length less than 2 m shall not vary by more than 3 mm from a straight line joining two points 1 m apart on that edge of the conductor.
NOTE No straightness requirement is specified for cut lengths shorter than I m.
8.3.2 Annealed conductors in cut lengths and conductors of any temper in. coil or on reels. The edge of a conductor of cut length of 2 m or over shall not vary by more than 20 mm from a straight line joining two points 2 m apart on that edge of the conductor. The edge of a conductor of cut length less than 2 m shall not vary by more than 5 mm from a straight line joining two points 1 m apart on that edge of the conductor.
NOTE No straightness requirement. is specified for cut lengths shorter than 1 m.
8.4 Corner radius
The dimensions and tolerances of the corner radii shall be as given in Table 8 for the appropriate
thickness.
For material supplied with corner radii or with semi-circular edges, the arc of curvature shall merge smoothly into the adjacent flat side and shall be free from sharp, rough or projecting corners.
9 Sampling
9.1 General
When tests are required to be carried out to verify that a batch complies with the mechanical property requirements of BS 1432 the samples shall be selected in accordance with 9.2 or 9.3.
The samples shall be of sufficient size to provide the necessary tensile and bend test specimens in accordance with Appendix E and Appendix F. The samples shall be cut off cold and shall not be subjected to any further treatment, other than machining to the shape and dimensions of the test specimens, before testing.
NOTE The procedure for selecting samples for the electrical resistivity and the hydrogen embrittlement tests, when required, should be agreed between the supplier and the purchaser at the time of enquiry and order (see item b) of A..2).
9.2 Samples for tensile test
Either:
a) one sample shall be taken at random for every 400 kg (or fraction thereof) contained in the batch; or
b) if the batch comprises one or more coils (or reels) each weighing more than 400 kg, one sample shall be taken to represent each coil.
9.3 Samples for bend tests
Either:
a) one sample shall be taken at random for every 800 kg (or fraction thereof) contained in the batch: or
b) if the batch comprises one or more coils (or reels) each weighing more than 800 kg, one sample shall be taken to represent each coil.
10 Testing
The tensile, bend, electrical resistivity and hydrogen embrittlement tests described in Appendix E to Appendix H shall be carried out on test pieces prepared from the samples selected in accordance with clause 9.
11 Retests
Should any one of the test pieces first selected fail the tests described in Appendix E to Appendix H, two further samples from the same batch shall be permitted to be selected for testing. One of these further samples shall be from the same conductor as that from which the original failed test sample was taken, unless that conductor had been withdrawn by the supplier.
Should the test pieces from both these additional samples pass the tests, the batch represented shall be deemed to comply with BS 1432. Should the test pieces from either of these additional samples fail the tests, the batch represented shall be deemed not to comply with this standard.
12 Expression of results
The results obtained from tests for chemical composition and tensile strength shall be rounded to the last place of figures specified as limits, by the application of the rounding rule in accordance with
BS 1957.