AS/NZS 2373:2003 pdf – Electric cables—Twisted pair for control and protection circuits

AS/NZS 2373:2003 pdf – Electric cables—Twisted pair for control and protection circuits.
9.3 Thickness
The average thickness of insulation, determined by the method specified in AS/NZS 1660.2.1, shall not be less than 1.5 mm and the minimum thickness at any point shall be not less than 1.30 mm.
NOTE: This requirement is designed to allow cables to withstand a voltage (under fault conditions) of 15 kV a.c. r.m.s. between the screen and the cores.
10 METALLIC SCREEN
10.1 General
The metallic screen shall be either a collective screen consisting of a tape or tapes applied
helically over the collective insulation or a moisture barrier sheath (see Clause 11).
10.2 Collective screen application
For a single tape a minimum overlap of 15 percent shall be provided. For more than one tape a gap may be used in each tape. provided the tbllowing tape is positioned centrally over the gap in the underlying tape.
10.3 Collective screen material
The screen material shall consist of copper. brass or aluminium tape having a minimum thickness of’ 0.070 mm or aluminium/polyester laminated tape having a minimum aluminium thickness of 0.023 mm.
10.4 Continuity conductor (drain wire)
Where an aluminium or aluminium/polyester helical tape is incorporated in the cable, a tinned copper stranded continuity conductor consisting of seven wires of at least 0.25 mm nominal diameter shall be included and it shall be in contact with the aluminium surface of the tape. It may be applied longitudinally and shall be continuous throughout the length of the cable.
11 MOISTURE HARRIER ShEATH (OPTIONAL)
The moisture barrier sheath shall consist of an aluminium laminated tape. longitudinally applied with a minimum overlap of 5 mm and an extruded layer of PU complying with
ASINZS 3808.
The thickness of the aluminium layer shall he approximately 0.15 mm and the composite thickness of the laminated tape shall be approximately 0.2 mm.
The overall thickness of the moisture barrier sheath shall comply with the requirements of a non-metallic sheath in AS/N/S 5000. I.
12 METALLIC SHEATH (OPTIONAL)
The metallic sheath shall be in accordance with AS/NZS 5000.1 and shall be applied over a
bedding complying with AS/NZS 5000.1. A moisture barrier sheath may be used as a
bedding.
The fictitious diameter under the bedding and the sheath shall be calculated using the method in Appendix C.