How do you select a cable size(Cu&Al) for a particular load

Answer Posted / gulderaiym

Factors like the length of the cable, resistance, current
being carried by the cable , short circuit current, voltage
drop all come into play when selecting cable to be used.

First calculate the load current

I = P / x V x pf
pf =0,9 according to TCO Standard P-ST-2035, point 9.9

Then find apparent power

For three phase: S = x V x I
For single phase: S = V x I

Then I find the resistance by Ohm's law:

Z = V / I
V - is particular Load

Then find the short circuit current

I short circuit = S / Z

Then find cable size

S = I sh.circuit x / k k = 143, t = 1

And then select the cable according to the cable catalogs

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