Medium voltage cable parameters

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Electrical parameters

Symbol Parameter Unit
Rcond20 Conductor resistance at 20
DC current
/km
Rcond90 Conductor resistance at 90
AC current
/km
Rscreen20 Metallic screen resistance at 20
DC current
/km
Rscreen80 Metallic screen resistance at 80
AC current
/km
- Electric field strength at conductor screen kV/mm
- Electric field strength at isolation kV/mm
R0 Zero sequence resistance /km
G Conductance S
X0 Zero sequence reactance /km
C Capacitance µF/km
B Susceptance S/km
Xc Capacitive reactance k/km
Ic Charging current kA/km
L Inductance - triangle formation, distance between centers of phases equals to diameter of cable mH/km
Inductance - flat formation, distance between centers of phases equals cable diameter mH/km
Inductance - flat formation, distance between centers of phases equals to diameter of cable + 70 mm mH/km
XL Inductive reactance - triangle formation, distance between centers of phases equals to diameter of cable /km
Inductive reactance - flat formation, distance between centers of phases equals cable diameter /km
Inductive reactance - flat formation, distance between centers of phases equals to diameter of cable + 70 mm /km
Z Impedance - triangle formation, distance between centers of phases equals to diameter of cable /km
Impedance - flat formation, distance between centers of phases equals 2 x cable diameter /km
Impedance - flat formation, distance between centers of phases equals to diameter of cable + 70 mm /km

Ampacity in Air and in Earth

Formation Parameter Unit
Flat Both ends bonded A
Single point bonding and cross-bonding A
Triangle Both ends bonded A
Single point bonding and cross-bonding A

Short circuit parameters

Part Parameter Unit
Conductor 1-s short circuit current kA
x-s short circuit current kA
Metallic screen 1-s short circuit current kA
x-s short circuit current kA
Cable Capacitive short-circuit current with earth A/km
Earth factor magnitude -
Earth factor angle deg

Mechanical parameters

Parameter Unit
Conductor diameter mm
Isolation thickness mm
Sheath thickness mm
Metallic screen cross-section mm
Diameter over metallic screen mm
External diameter of cable mm
Cable weight kg/km
Max. pulling force kN
Min. bending radius m