In document ISO 10303-226, a fault is defined as an abnormal condition or defect at the component, equipment, or sub-system level which may lead to a failure.
In telecommunications, according to the Federal Standard 1037C of the United States, the term fault has the following meanings:
- An accidental condition that causes a functional unit to fail to perform its required function. See § Random fault.[1]
- A defect that causes a reproducible or catastrophic malfunction. A malfunction is considered reproducible if it occurs consistently under the same circumstances. See § Systematic fault.
- In power systems, an unintentional short circuit, or partial short circuit, between energized conductors or between an energized conductor and ground. A distinction can be made between symmetric and asymmetric faults. See Fault (power engineering).