How do you select a cable size(cu&Al)for a particular load?
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Answer Posted / sreenu
Based on KW/HP value the current rating can be caluculated
and based on current rating of Mains & cable size can be
caluculated.
for example.
HP of the motor is :A HP
KW of load is :A HP/735.5*Efficiency(E).
Generally eddicieny of the motor can be asuumed 0.8 to 0.9
Current(C) is :A HP/735.5*E*(1.73*V* cosQ)
Cos Q generally asumed as 0.8 to 0.9
If the value of current is C, the current capacity of cable
reuired is Appx. 1.5*C.
Based on cable catalogue provided by the cable manufacturer
the size of the cable can be selected.
For eample. If you use al. cable, the size of cable is
bigger than copper cable.
Rating of mains: 1.5* C, but fuse arting is C only.
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