Written by Ampacity is the current, in amperes, that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.
All electrical conductors have some resistance to the flow of electricity, and electric current flowing through them causes voltage drop and power dissipation, which heats the cable. Copper or aluminum can conduct a large amount of current before melting, but long before the conductors melt, their insulation would be damaged by the heat.
