Cableizer ®

Temperature screen

The formulae to calculate the loss factor for screen $\lambda_1$ use the resistance of the screen $R_{sh}$ at its maximum operating temperature. Because the temperature of the screen is a function of the current, $I_c$, an iterative method is used for the calculation.

With crossing heat sources, a temperature rise of $\Delta\theta_{0x}$ applies at the hottest point.

Symbol
$\theta_{sc}$
Unit
°C
Formulas
$\theta_{c}-T_{1} \left(W_{c}+\frac{W_{d}}{2}\right)$
Related
$\Delta \theta_{0x}$
Temperature rise by crossing heat sources [K]
$T_{1}$
Thermal resistance conductor—sheath [K.m/W]
$\theta_{c}$
Temperature conductor [°C]
$W_{c}$
Conductor losses (phase) [W/m]
$W_{d}$
Dielectric losses (phase) [W/m]
Used in
$R_{sc}$
Electrical resistance screen [$\Omega$/m]
$\rho_{sc}$
Specific electrical resistivity screen material [$\Omega$.m]
$\theta_{s}$
Temperature screen/sheath [°C]
$\theta_{sh}$
Temperature sheath [°C]
$\theta_{spf}$
Mean temperature medium in the steel pipe [°C]