Short-Circuit Current (IEC 61363)

Peak and RMS symmetrical short-circuit currents on a shipboard bus - IEC 61363-1 approach for switchgear sizing.

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Generator MVA ratingMVASystem voltage (line-line)VX″d subtransient reactance (pu)puPeak factor κ -

Base current: 3,280A

RMS symmetrical SC (I″k): 23,431A

Peak SC (i_p): 59,647A

Changing the inputs requires JavaScript. The calculator above shows its default inputs and result. The formula, symbols, and regulatory sources are shown in the Formula section below.

Formula, assumptions, and limits

I''_k = \frac{I_\text{base}}{X''_d}, \quad i_p = \kappa \cdot \sqrt{2} \cdot I''_k

Symbol	Meaning	Unit
$I_\text{base}$	Base current = MVA/(√3·V)	A
$X''_d$	Sub-transient reactance pu	pu
$κ$	Peak factor
$I''_k$	RMS symmetrical SC	A
$i_p$	Peak SC	A

Source: IEC 61363-1 - Short-circuit calculation for shipboard installations

In short

Peak and RMS symmetrical short-circuit currents on a shipboard bus - IEC 61363-1 approach for switchgear sizing.

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