short circuit (redirected from short-circuits)

short circuit, abnormal connection of low resistance between two points of a circuit that usually causes a high, potentially damaging current to flow. To protect against damage, devices such as a fuse or a circuit breaker are used. They sense the excess current and break the circuit so that no current can flow. They must be replaced or reset manually once the cause of the short circuit is removed.

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short circuit

a faulty or accidental connection between two points of different potential in an electric circuit, bypassing the load and establishing a path of low resistance through which an excessive current can flow. It can cause damage to the components if the circuit is not protected by a fuse

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short circuit [′shȯrt ′sər·kət]

(electricity)

A low-resistance connection across a voltage source or between both sides of a circuit or line, usually accidental and usually resulting in excessive current flow that may cause damage. Also known as short.

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Short circuit

An abnormal condition (including an arc) of relatively low impedance, whether made accidentally or intentionally, between two points of different potential in an electric network or system. See Electrical impedance

Common usage of the term implies an undesirable condition arising from failure of electrical insulation, from natural causes (lightning, wind, and so forth), or from human causes (accidents, intrusion, and so forth). From an analytical viewpoint, however, short circuits represent a severe condition that the circuit designer must consider in designing an electric system that must withstand all possible operating conditions.

In circuit theory the short-circuit condition represents a basic condition that is used analytically to derive important information concerning the network behavior and operating capability. Thus, along with the open-circuit voltage, the short-circuit current provides important basic information about the network at a given point.

The short-circuit condition is also used in network theory to describe a general condition of zero voltage. Thus the term short-circuit admittance (or impedance) is used to describe a network condition in which certain terminals have had their voltage reduced to zero for the purpose of analysis. This leads to the terms short-circuit driving point admittance, short-circuit transfer admittance, and similar references to the zero voltage condition. See Admittance

Short-circuit protection is a separate discipline dedicated to the study, analysis, application, and design of protective apparatus that are intended to minimize the effect of unintentional short circuits in power supply systems. For these analyses the short circuit is an important limiting (worst) case, and is used to compute the coordination of fuses, circuit reclosers, circuit breakers, and other devices designed to recognize and isolate short circuits. The short circuit is also an important parameter in the specification of these protective devices, which must have adequate capability for interrupting the high short-circuit current.

Short circuits are also important on high-frequency transmission lines where shorted stub lines, one-quarter wavelength long and shorted at the remote end, are used to design matching sections of the transmission lines which also act as tuning elements.