Medium Voltage Power Cables Catalogue - AEC Online

D.7 Short Circuit Capacity
Tables F.2 and F.3 give the short circuit current for conductor
based on the following conditions:
A. Short circuit starts from the maximum operating conductor
temperature 90 °C
B. Maximum temperature during short circuit 250 °C
C. Maximum short circuit current duration is 5 seconds.
If the short circuit current is required at duration not mentioned
in the catalogue, it is obtained by dividing the short circuit
current for 1 second by the square root of the required duration
as follows:
Where;
Short circuit current for t second
Short circuit current for 1 second
Duration
D.8 Voltage Drop
During current flows in a cable conductor there is a voltage drop
between the ends of the conductors, which is the product of the
current and the impedance. The following equations should be
used to calculate the voltage drop of three-phase circuit:
Where
Where
Where
Voltage drop
Load current
Route length
AC Resistance
Reactance
Power factor
2 π f
Operating frequency
inductance
km
km
km
km
km
Relation between Cos θ and Sin θ: