Cableizer ®

Electrical resistance sheath

Electrical resistance of sheath at operating temperature.

Symbol
$R_{sh}$
Unit
$\Omega$/m
Formulas
${10}^6\frac{\rho_{sh}}{A_{sh}}$at 20°C
${10}^6\frac{F_{cor,sh} \rho_{sh}}{A_{sh}}$CIGRE TB 880 Guidance Point 30, at 20°C
$R_{sh} \left(1+\alpha_{sh} \left(\theta_{sh}-20\right)\right)$at operating temperature
$F_{lay,3c} R_{sh}$CIGRE TB 880 Guidance Point 27, at operating temperature
Related
$A_{sh}$
Cross-sectional area sheath [mm$^2$]
$\alpha_{sh}$
Temperature coefficient sheath material [1/K]
$F_{cor,sh}$
Effective length per unit pitch length corrugated sheath
$F_{lay,3c}$
Effective length per unit lay length twisted conductors
$\rho_{sh}$
Specific electrical resistivity sheath material [$\Omega$.m]
$\theta_{sh}$
Temperature sheath [°C]
Used in
$\lambda_{11,sc}$
Loss factor screen, circulating currents
$\lambda_{11,sh}$
Loss factor sheath, circulating currents
$\lambda_{12}$
Loss factor shield, eddy currents
$m_0$
Substitution coefficient $m_0$ for eddy-currents [Hz.m/$\Omega$]
$R_e$
Electrical resistance shield/armour [$\Omega$/m]
$R_s$
Electrical resistance shield [$\Omega$/m]
$R_{so}$
Electrical resistance screen/sheath 20°C [$\Omega$/m]