Answer / sindhejs

With knowing the kW rating and voltage, the current can be
calculated as I=P/(sr(3)*V*pf). The pf can be assumed to be
as 0.8. After knowing the current, choose the 10% higher
current carrying capacity cable for the safety purpose.

current rating for differnt cables are different for same
size.Copper has higher current carrying capacity.

Answer / moh. baheer

We can so easy calculate the current and choose the cable
size form chart if we have the quantities of Voltage (Volt)
and total power (KW) please find from this formula the
current rate according to the load (kW).
P = U*I*cosФ
I = P/U =?
Then we can choose the cable size from chart according to
current.
Regards

Answer / shahidul islam (srabon)

When the power is known in kW then the formula for knowing
the current in A is I=(P/(sr(3)*V(phase)). Now we the
current. After finding the current we know that the current
density of copper is 2.5. Finally to calculate the cable
isze we apply the given formula in practice.
I=A*2.5
so, A=I/2.5 (in square mm)
Where A=Area of conductor or here cooper is used
A=w*l
w=width
L=length of the conductor
Hope the answer of the question

Answer / abdul rahman

While all loads are given in KW,only current matters while calculating cable sizing assuming voltage remains constant neglecting minor fluctuations.
From power equation once u find the load current you decide the cable sizing.As a thumb rule 1sq mm of Cu carries 2.4A whereas Al carries 1.4A. 
For example a 100kw load requires nearly 180A current.The cable sizing would be 4core X 95 sqmm Cu plus 1core 50 sqmm ECC.
Different manufacturers have their standard sizes hence the value main differ slightly but the thumb rules will help u.

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