Thermal resistivity of insulation
The values of the thermal resistivity of insulation are taken from standard IEC 60287-2-1 Ed.2.0 where available with the following additions:
- For the purposes of current rating calculations, the semi-conducting screening materials are assumed to have the same thermal properties as the adjacent dielectric materials.
- Value for Polypropylene (PP) is based on the minimal value of thermal conductivity (0.17 to 0.22) given in the book 'Polypropylene - The Definitive Users Guide and Databook', Plastics Design Library, 1998. whereas a range of 0.10 to 0.23 is given by professionalplastics.com
- Value for Silicone rubber (SiR) is taken from shinetsusilicone-global.com
- Value for Ethylene vinyl acetate (EVA) is taken from expresspolymlett.com and J. Allan and Z. Dehouche: 'Enhancing the thermal conductivity of ethylene-vinyl acetate (EVA) in a photovoltaic thermal collector', 2016 ().
|PVC||5.0 (U_n <= 3kV)|
6.0 (U_n > 3kV)
|EPR||3.5 (U_n <= 3kV)|
5.0 (U_n > 3kV)
5.0 (pipe-type oil-filled)
5.5 (pipe-type gas pressure)