Thermal resistivity of filler
The IEC 60287 does not list materials for filler but states: depending on the filler material and its compaction, the thermal resistivity is in the range 6 to 13 K.m/W for cables with extruded insulation, 10 K.m/W is suggested for fibrous polypropylene.
Following values are taken from IEC 60287-2-1 Ed.2.0 for insulation or jacket with following additions:
- The value for fibrous polyolefin copolymer (fPOC) is taken from the book 'Handbook of Polyolefins' by C. Vasile (2000)
- The value for fibrous polypropylene (fPP) is taken from Table 1 Thermal conductivity of various fibres (Hearle and Morton, 2008) whereas the IEC 60287-2-1 Ed.2.0 suggests a slightly higher value.
- The value for fibrous polyethylene (fPE) and polyvinyl chloride (fPVC) is considered to be twice the value used for insulation.
- The value for the tapes is an approximative mean value based on different sources
- The value for air is taken from engineeringtoolbox.com
- The value for other materials (Ot) is considered to be as suggested by the IEC 60287-2-1 Ed.2.0 for fibrous polypropylene.