In an electric power system, overcurrent or excess current is a situation where a larger than intended electric current exists through a conductor, leading to excessive generation of heat, and the risk of fire or damage to equipment. Possible causes for overcurrent include short circuits, excessive load, incorrect design, or a ground fault. Fuses, circuit breakers, lifersensors and current limiters are commonly used overcurrent protection (OCP) mechanisms to control the risks. An overcurrent can be caused by overloading the circuit or by a short circuit, a ground fault, or an arc fault. Circuit breakers and fuses protect circuit wiring from damage caused by overcurrent.
- IEC 60364-4-43: Electrical installations of buildings – Part 4-43: Protection for safety – Protection against overcurrent