Cableizer ®

Phase-to-neutral fault current

Definition according to Schneider Electric Cahier technique 158 (2000), chap. 2.1)

This is a fault between one phase and the neutral, supplied with a phase-to-neutral voltage $U/\sqrt{3}$. The short-circuit current $I_{sc_1}$ is:
$I_{sc_1} = \frac{U/\sqrt{3}}{Z_{sc}+Z_{Ln}}$

In certain special cases of phase-to-neutral faults, the zero-sequence impedance of the source is less than the short-circuit impedance $Z_{sc}$ (for example, at the terminals of a star-zigzag connected transformer or of a generator under subtransient conditions). In this case, the phase-to-neutral fault current may be greater than that of a three-phase fault.

Symbol
$I_{k1}$
Unit
A
Used in
$I_{ka}$
Complex conductor current a [A]
$I_{kb}$
Complex conductor current a [A]
$I_{kc}$
Complex conductor current c [A]