Install Instructions

24 S1A53832 03/2019
Prospective Short-Circuit Current
Calculation
The prospective short-circuit current shall be computed at the drive connection points.
We recommend using the Schneider Electric tool Ecodial Advance Calculation available on
https://www.se.com/en/product-range-presentation/61013-ecodial-advance-calculation/
The following equations allow to estimate the value of the symmetrical three-phase prospective short-circuit
current (Isc) at the drive connection points.
Isc
Symmetrical three-phase prospective short-circuit current (kA)
Xt
Transformer reactance
U
No-load phase to phase voltage of the transformer (V)
Sn
Apparent transformer power (kVA)
usc
Short-circuit voltage, according to the transformer data sheet (%)
Zcc
Total short-circuit impedance (mΩ)
ρ
Conductor resistivity e.g. Cu: 0.01851 mΩ.mm
l
Conductor length (mm)
S
Conductor cross section (mm
2
)
Xc
Conductor lineic reactance (0.0001 mΩ/mm)
Rf, Xf
Resistance and reactance of the line filter (mΩ)
(see page 26)