In multi-core cables, the axial separation depends on the construction of sreen and sheath.

In single-core cables, the axial separation depends on the laying: In trefoil formation, the separation is the axial spacing between the phases: $s_c = s_{cf}$ whereas in flat or individual formation, the separation is the geometric mean of the spacing between the cables or ducts.

- For systems with three phases, we take the maximum value of the geometric mean of the spacing for any two cables, $\sqrt{s_{RS}s_{ST}}, \sqrt{s_{RS}s_{RT}}, \sqrt{s_{RT}s_{ST}}$.
- For systems with three phases and phase-split, we take the mean value between the maximum for each group, calculated as above.
- For systems with two phases and phase-split, which are usually in square arrangement, we take the mean value of the distances between the phases.

$s_{\mathrm{c}}$

mm

$d_{\mathrm{x}} + t$ | multi-core cables with common screen/sheath |

$d_{\mathrm{x}} + t + 2 t_{\mathrm{sc}} + 2 t_{\mathrm{scb}} + 2 t_{\mathrm{scs}}$ | multi-core cables with separate screen and common sheath |

$D_{\mathrm{oc}}$ | multi-core cables with separate screen/sheaths |

$d_{\mathrm{x}}$

$s_{\mathrm{c2}}$

Separation of cables [mm]

$t_{\mathrm{sc}}$

$t_{\mathrm{scb}}$

$t_{\mathrm{scs}}$

$\Delta _{\mathrm{1}}$

$\Delta _{\mathrm{2}}$

$GMD$

$\lambda_{\mathrm{0}}$

$\lambda_{\mathrm{1es}}$

$\lambda_{\mathrm{2}}$

$\lambda_{\mathrm{3}}$

$X_{\mathrm{s}}$

$X_{\mathrm{S1}}$

Reactance section 1 [Ω/m]

$X_{\mathrm{S2}}$

Reactance section 2 [Ω/m]

$X_{\mathrm{S3}}$

Reactance section 3 [Ω/m]

$y_{\mathrm{p}}$