Transformer - Required kVA Rating

Required transformer kVA rating given 3-phase secondary load, voltage, power-factor and 20 % safety margin.

TransformerkVAMarine

Load on secondarykWPower factorDesign margin%

Calculated kVA: 352.9kVA

Standard size: 400 kVA

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

S = \frac{P}{\cos\varphi} \cdot (1 + m)

Symbol	Meaning	Unit
$P$	Active load	kW
$\cos\varphi$	Power factor
$m$	Design margin

Source: IEC 60076 / IEC 60092-302

In short

Required transformer kVA rating given 3-phase secondary load, voltage, power-factor and 20 % safety margin.

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