What is an Electrical Short Circuit?
An electrical short circuit is a fault that occurs when a low resistance path exists between the hot lead and some grounded points. When an electrical short circuit occurs, heavy current will flow in the circuit for as long as it takes for the circuit breaker to trip to OFF or for the fuse to blow. Because a properly-working circuit breaker or fuse cuts off the current flow quickly, the circuit wiring will not have time to overheat to the point where fire may occur. Sketch courtesy of Carson Dunlop. Safety warning: an over-sized or improperly-installed fuse, and also some circuit breakers do not work reliably; a circuit breaker that is damaged by rust, corrosion, modification, or a circuit breaker which was poorly designed in the first place may not trip – resulting in a fire. See FEDERAL PACIFIC FPE HAZARDS, ZINSCO / SYLVANIA HAZARDS, CIRCUIT BREAKER FAILURE for some examples of problem circuit breakers.
