AS 1049.1:2014 Australian Standard Telecommunication cables—Insulation, sheath and jacket
3.1.2 Material selection
The highest performance required of insulation material is from installed cable in long service life (greater than 20 years) applications, jointed in outdoor above-ground enclosures that are subject to a severe thermal environment (‘more severe condition’). In such circumstances the entire cable may be designed to survive conditions that only the terminated ends will experience. Due to the need for ease of re-entry, and standardized work practices, there are applications that cannot avoid such conditions, and therefore require the performance of materials and rigour of testing to prove suitability of purpose. However, with lesser service requirements and more protective methods of termination, alternative materials and tests for suitability are presented (‘less severe condition’ and ‘other cables’).
3.1.3 Cables jointed outdoors
There are two applications for ‘cables jointed outdoors’ in Tables 3.1 and 3.2: ‘less severe condition’ and ‘more severe condition’. The minimum performance specifications that shall be adopted are the following:
(a) Less severe condition Based on EN 50290-2-23.
(b) More severe condition Based on the Telcordia (formally Bellcore) Pedestal and OIT tests from GR 421-CORE. The Telcordia Pedestal text is referred to in AS 1049.2 as the ‘environmental ageing method’ (Appendix FF). This test shall be conducted for initial qualification. Filled cables generally degrade faster than similar insulation used in dry core cables, so testing a filled cable will qualify a dry core cable. ‘The environmental ageing method’ test shall be conducted on the smallest insulation radial, and this will qualify the full range of insulation sizes for the same insulation material.
By default, cables meeting the requirements of the ‘more severe condition’ shall be deemed suitable for use in the ‘less severe condition’.
3.2.4 Stabilizers
For the stabilizers to function effectively, it is important that they are homogeneously dispersed throughout the polymer matrix. This is best achieved by the cable manufacturer using a fully compounded PE material supplied by the polymer compounder. Stabilizer masterbatches do not provide sufficient dispersion when added to the PE base material by the cable manufacturer when extruding insulation on conductor.