Insulation thickness between conductors and sheath used to calculate $T_1$ with following considerations:

- For multi-core cables, $t_1$ is up to the sheath and $t_2$ is between sheath and armour.
- A tape screen is considered equivalent to a sheath, so for single-core cables with a tape screen and no sheath and for multi-core cables with a common screen and no sheath, the screen serving is added to $t_2$.
- A wired screen is not relevant for the calculation.
- For multi-core cables with separate sheaths, the filler is part of $t_2$.

Type of screen/sheath of multi-core cables

- SS: with separate screen and separate sheaths
- SC: with separate screen and common sheath
- CC: with common screen and common sheath

$t_{\mathrm{1}}$

mm

$\frac{t}{2} + t_{\mathrm{scb}}$ | single-core with tape screen |

$\frac{t}{2} + t_{\mathrm{f}} + t_{\mathrm{scb}}$ | multi-core cables type CC with tape screen and no sheath |

$\frac{\Delta d_{\mathrm{sh}}}{2} + \frac{t}{2} + t_{\mathrm{scb}} + t_{\mathrm{scs}}$ | other single-core cables / three-core cables type SS with sheath |

$\frac{\Delta d_{\mathrm{sh}}}{2} + \frac{t}{2} + t_{\mathrm{f}} + t_{\mathrm{scb}} + t_{\mathrm{scs}}$ | other multi-core cables |

$t_{\mathrm{f}}$

$t_{\mathrm{scb}}$

$t_{\mathrm{scs}}$

$T_{\mathrm{1}}$

$t_{\mathrm{1t}}$

$X_{\mathrm{G}}$

Factor X_{G} [-]

$Y_{\mathrm{G}}$

Factor Y_{G} [-]

$Y_{\mathrm{K}}$

Factor Y_{K} [-]