Answer / manikandan

current rating cable depends upon manufacture (make cu
percentage) for the cable selection first calculate the
cable length and voltage drop,total impedance ect..

Answer / gnd kumaran

First calculate the load current.
Then select the cable according to the current carrying
capacity.[To know the current carrying capacity, refer
cables catalog]


Load Current X Length of the cable X Voltage drop per Amps
per Meter [in milli volts]/ 1000
now we will get voltage drop
If voltage drop is below 3- 5 percentage, you can choose
the above cable, if it is more than 3-5 percentage, go to
next higher size and repeat the calculation.

Answer / shailesh

conductore size (cu 3A/Sqmm and Al 1A/Sqmm )but in case of
cable it depends on its type of used.for ex-for cu-1sqmm
can take 11A. when it used in pvc conduits in indoor.

Answer / pillay

I like to add a bit more to Gnd Kumarans answer.
INCLUDE LOAD CURRENT, LENGTH,VOLT DROP AND
1)Type of cable cu/ al, underground, pvc etc
2}how you want to lay eg overhead line, conduit,
underground. cable tray, trunking.
3)if necessary type of protection you are giving
than with the help of the manufacturers cable catalogue you
can safely determine the cable size.
there is no fast rule to say cu cables carry 2.;5 times &al
cables carry 1.5 times the cable size to determine the cable
size.

Answer / rsbangra

cupper cable take 2.5 times current its ratting in mm2
and aluminiuam cable taken 1.5 times of its ratting.

exampl. 10 mm2 alu. cable take 15 amp current
and cupper cable 10 mm2 cable take 25-30 amp.

Answer / mohit.k.k

it depends upon length. but you can take it as for al cable
1 sqmm = 1a and for cu 1sqmm = 2.5 a

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