Temperature of screen/sheath

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

Symbol
$\theta_{s}$
Unit
$^{\circ}$C
Formulae
$- T_{1} \left(W_{c} + \frac{W_{d}}{2}\right) + \theta_{c}$
$\theta_{c}$
$W_{c}$
$W_{d}$