Thermal resistance jacket

Symbol
$T_{j}$
Unit
K.m/W
Formulas
$\frac{\rho_{j}}{2\pi} \ln\left(\frac{D_{j}}{D_{j}-2\left(t_{j}+t_{jj}\right)}\right)$IEC 60287-2-1
$\frac{\rho_{j}}{2\pi} \ln\left(\frac{D_{j}-2t_{jj}}{D_{j}-2\left(t_{j}+t_{jj}\right)}\right)$CIGRE TB 880 Guidance Point 15
Used in