Choice of Electric cable

The essential components of a cable are a metallic conductor of low resistivity to carry the current and insulation around cable which provide dielectric medium for isolating conductors from one another and from their surroundings.

It is recommended that always choose the correct size of cable that is big enough to avoid wasted power in the form of excessive voltage drop. This wasted power is used in heating the cable, causing the temperature may be rise sufficiently to damage or even destroy the insulation of the cable and also efficiency of electrical devices is decreased. Cheaper cables are not good for electric wiring, because the power loss and voltage drop in these cables are very high.

Electric cables

The chose the correct size of cable for electric  wiring, some important points to be remember.

(1) Conductor material.
(2) Insulation.
(3) Type of wiring.
(4) Bunching.
(5) Load current.
(6) Voltage drops.
(7) Ambient temperature.
(8) Mechanical injury.
(9) Condition of installation at site.
(10) Short circuit capacity of a cable.