What is an electrical short-circuit or overload?
A short circuit occurs when there is unintended or accidental contact between conductors in a system caused, for example, by a failure of the insulation in the equipment, or a metal tool such as a pick axe being driven into a live cable, or a metal object being dropped onto live parts in electrical equipment.
An overload occurs when more electrical current flows in a system than the system was designed to carry, leading to overheating and the possibility of fire.