Factor $\beta_M$

Factor $\beta_M$ for the calculation of the geometric factor for multi-core cables according to IEC 60287-2-1.

Symbol
$\beta_M$
Formulae
$\frac{\alpha_M \left(\frac{X_G}{1+Y_G}-0.5\right)}{\frac{X_G}{1+Y_G}+1.5}$$n_c<=2$
$\frac{\alpha_M \left(\frac{2}{\sqrt{3}} \left(1+\frac{2X_G}{1+Y_G}\right)-3\right)}{\frac{2}{\sqrt{3}} \left(1+\frac{2X_G}{1+Y_G}\right)+3}$$n_c>=3$