This is the loss factor for sheath and screen bonded at both ends caused by circulating currents. When a non-magnetic armour is present, $R_s$ is replaced by $R_e$ in the following formulas.

Symbol
$\lambda_{\mathrm{1cb}}$
Unit
-
Formulae
$\frac{R_{\mathrm{s}}}{R \left(\frac{R_{\mathrm{s}}^{2}}{X_{\mathrm{s}}^{2}} + 1\right)}$two single-core cables and three single-core cables in trefoi}
$\frac{R_{\mathrm{s}}}{R \left(\frac{R_{\mathrm{s}}^{2}}{X_{\mathrm{s}}^{2}} + 1\right)}$three single-core cables in flat formation, with regular transposition
$\frac{R_{\mathrm{s}}}{R} \left(\frac{0.75 P_{\mathrm{cc}}^{2}}{P_{\mathrm{cc}}^{2} + R_{\mathrm{s}}^{2}} + \frac{2 \sqrt{3} P_{\mathrm{cc}} Q_{\mathrm{cc}} R_{\mathrm{s}} X_{\mathrm{m}}}{3 \left(P_{\mathrm{cc}}^{2} + R_{\mathrm{s}}^{2}\right) \left(Q_{\mathrm{cc}}^{2} + R_{\mathrm{s}}^{2}\right)} + \frac{0.25 Q_{\mathrm{cc}}^{2}}{Q_{\mathrm{cc}}^{2} + R_{\mathrm{s}}^{2}}\right)$3 cables, flat formation, not transposed, outer cable with greates loss (lagging phase R/1)
$\frac{Q_{\mathrm{cc}}^{2} R_{\mathrm{s}}}{R \left(Q_{\mathrm{cc}}^{2} + R_{\mathrm{s}}^{2}\right)}$3 cables, flat formation, not transposed, middle cable (2/S)
$\frac{R_{\mathrm{s}}}{R} \left(\frac{0.75 P_{\mathrm{cc}}^{2}}{P_{\mathrm{cc}}^{2} + R_{\mathrm{s}}^{2}} - \frac{2 \sqrt{3} P_{\mathrm{cc}} Q_{\mathrm{cc}} R_{\mathrm{s}} X_{\mathrm{m}}}{3 \left(P_{\mathrm{cc}}^{2} + R_{\mathrm{s}}^{2}\right) \left(Q_{\mathrm{cc}}^{2} + R_{\mathrm{s}}^{2}\right)} + \frac{0.25 Q_{\mathrm{cc}}^{2}}{Q_{\mathrm{cc}}^{2} + R_{\mathrm{s}}^{2}}\right)$3 cables, flat formation, not transposed, other outer cable (leading phase T/3)
$0$multi-core cables with common screen and/or common sheath
$\frac{R_{\mathrm{sc}}}{R \left(\frac{R_{\mathrm{sc}}^{2}}{X_{\mathrm{s}}^{2}} + 1\right)}$multi-core cables with separate screen and common sheath or no sheath)
$\frac{1.5 R_{\mathrm{s}}}{R \left(\frac{R_{\mathrm{s}}^{2}}{X_{\mathrm{s}}^{2}} + 1\right)}$multi-core cables with separate sheaths, armoured
$\frac{1.0 R_{\mathrm{s}}}{R \left(\frac{R_{\mathrm{s}}^{2}}{X_{\mathrm{s}}^{2}} + 1\right)}$multi-core cables with separate tape screen and/or separate sheaths, unarmoured (pipe-type)
$\frac{1.0 R_{\mathrm{e}}}{R \left(\frac{R_{\mathrm{e}}^{2}}{X_{\mathrm{s}}^{2}} + 1\right)}$multi-core cables with separate tape screen, without sheath, with non-magnetic armour (pipe-type)
$R_{\mathrm{e}}$
$X_{\mathrm{m}}$
$X_{\mathrm{s}}$
Used in
$\lambda_{\mathrm{1c}}$
$\lambda_{\mathrm{2}}$