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 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 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 for fibrous polypropylene.

Symbol

$\rho_f$

Unit

K.m/W

Related

$M_f$

Material of filler

Used in

$T_1$

Thermal resistance between one conductor and sheath [K.m/W]

$T_2$

Thermal resistance of armour bedding [K.m/W]

Choices

Material	Value
fPOC	6.6
fPP	9.0
fPE	7.0
fPVC	12.0
sPVC	6.0
sPE	3.5
PRod	8.0
PTube	12.0
OilD	6.0
TY	5.3
Jute	6.0
tape	6.0
Air	38.2
Ot	10.0