Skin and proximity effect coefficient b for PAC/GIL enclosure

The coefficient is not used for calculation of skin effect factor for PAC/GIL enclosure as falsely written in CIGRE Guide 2018 (2003).

Symbol

$b_{encl}$

Formulae

$\frac{56}{211+{z_{encl}}^2}$	$z_{encl}<5$
$\frac{2}{4\sqrt{2z_{encl}}-5}$	$z_{encl}>30$
$0.5356-2.1030734{\cdot}{10}^{-1} z_{encl}+6.495563{\cdot}{10}^{-2} {z_{encl}}^2-1.089373{\cdot}{10}^{-2} {z_{encl}}^3+1.0372874{\cdot}{10}^{-3} {z_{encl}}^4-5.8238557{\cdot}{10}^{-5} {z_{encl}}^5+1.9109965{\cdot}{10}^{-6} {z_{encl}}^6-3.3893677{\cdot}{10}^{-8} {z_{encl}}^7+2.509622{\cdot}{10}^{-10} {z_{encl}}^8$	otherwise

Related

$z_{encl}$