Editing Short circuit (section)

== Examples ==
A common type of short circuit occurs when the positive and negative terminals of a [[Battery (electricity)|battery]] or a [[capacitor]] are connected with a low-[[electrical resistance|resistance]] [[Electrical conductor|conductor]], like a [[wire]].  With a low resistance in the connection, a high [[Current (electricity)|current]] will flow, causing the delivery of a large amount of energy in a short period of time.

A high current flowing through a battery can cause a rapid increase of temperature, potentially resulting in an explosion with the release of [[hydrogen]] gas and [[electrolyte]] (an [[acid]] or a [[base (chemistry)|base]]), which can burn tissue and cause blindness or even death. Overloaded wires will also [[Overheating (electricity)|overheat]] causing damage to the wire's insulation, or starting a fire. 

In electrical devices, unintentional short circuits are usually caused when a wire's [[Electrical insulation|insulation]] breaks down, or when another conducting material is introduced, allowing charge to flow along a different path than the one intended.

In [[Mains electricity|mains]] circuits, short circuits may occur between two [[Polyphase system|phases]], between a phase and [[Ground and neutral|neutral]] or between a phase and [[Ground and neutral|earth]] (ground).  Such short circuits are likely to result in a very high current and therefore quickly trigger an overcurrent protection device. However, it is possible for short circuits to arise between neutral and earth conductors and between two conductors of the same phase. Such short circuits can be dangerous, particularly as they may not immediately result in a large current and are therefore less likely to be detected. Possible effects include unexpected energisation of a circuit presumed to be isolated. To help reduce the negative effects of short circuits, power distribution transformers are deliberately designed to have a certain amount of [[Leakage inductance|leakage reactance]]. The leakage reactance (usually about 5 to 10% of the full load impedance) helps limit both the magnitude and rate of rise of the [[fault current]].
[[File:Melting an iron nail.webm|thumb|Short-circuiting a 3000 [[farad]] [[supercapacitor]] through an iron nail resulted in a 1000 [[amperes]] current. This caused the iron nail to melt, eject [[Spark (fire)|sparks]], and eventually break, becoming an open circuit.]]
A short circuit may lead to formation of an [[electric arc]]. The arc, a channel of hot ionized [[plasma (physics)|plasma]], is highly conductive and can persist even after significant amounts of original material from the conductors has evaporated. Surface erosion is a typical sign of electric arc damage. Even short arcs can remove significant amounts of material from the electrodes. The temperature of the resulting electrical arc is very high (tens of thousands of degrees), causing the metal on the contact surfaces to melt, pool and migrate with the current, as well as to escape into the air as fine particulate matter.<ref>{{cite web | title = Lab Note #105 ''Contact Life - Unsuppressed vs. Suppressed Arcing'' | publisher = Arc Suppression Technologies | date = April 2011 | url = http://www.arcsuppressiontechnologies.com/arc-suppression-facts/lab-app-notes/ | access-date = February 5, 2012 | archive-date = September 30, 2018 | archive-url = https://web.archive.org/web/20180930071357/http://www.arcsuppressiontechnologies.com/arc-suppression-facts/lab-app-notes/ | url-status = live }}</ref>