Like garden hoses, electrical
wires are only designed to carry a limited amount of current to prevent short
circuits. Unlike water and garden hoses, however, the current capacity of a
wire is not directly proportional to the gauge.
A six-gauge wire
(American Wire Gauge standards), for instance, has a 4.11mm diameter and a
current capacity of 37 amps for power transmission, while a twelve-gauge wire
only has a 2.05mm diameter and 9.3 amps—more than half the capacity. This isn't
just because the wire is smaller; the electrical resistance grows as it
shrinks.
