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Power outages are categorized into three different phenomena, relating to the duration and effect of the outage: A transient fault is a loss of power typically caused by a fault on a power line, e.g. a short circuit or flashover. Power is automatically restored once the fault is cleared. A brownout is a drop in voltage in an electrical power ...
Forced outage rate (FOR or FOAR) of a power station unit is the probability that the unit will not be available for service when required.. FOR is defined as the number of hours the unit is on forced outage over the total number of hours in a year (which is the sum of hours the power station is available for service and hours the power station is in forced outage).
In an electric power system, a fault or fault current is any abnormal electric current. For example, a short circuit is a fault in which a live wire touches a neutral or ground wire. An open-circuit fault occurs if a circuit is interrupted by a failure of a current-carrying wire (phase or neutral) or a blown fuse or circuit breaker .
Power system protection is a branch of electrical power engineering that deals with the protection of electrical power systems from faults [citation needed] through the disconnection of faulted parts from the rest of the electrical network. The objective of a protection scheme is to keep the power system stable by isolating only the components ...
A switched-mode power supply will be affected if the brownout voltage is lower than the minimum input voltage of the power supply. As the input voltage falls, the current draw will increase to maintain the same output voltage and current, until such a point that the power supply malfunctions or its under-voltage protection kicks in and disables ...
An earth-leakage circuit breaker (ELCB) is a safety device used in electrical installations with high Earth impedance to prevent shock. It detects small stray voltages on the metal enclosures of electrical equipment, and interrupts the circuit if a dangerous voltage is detected.
Tree limbs cause a short circuit, triggering an electrical arc during a storm. A short circuit (sometimes abbreviated to short or s/c) is an electrical circuit that allows a current to travel along an unintended path with no or very low electrical impedance. This results in an excessive current flowing through the circuit.
Generally, either an electric motor with shorted windings or a shorted power-transformer is the culprit, being capable of drawing the energy needed to sustain a dangerous arc-flash. Motors over two horsepower usually have magnetic starters , to both isolate the operator from the high-energy contacts and to allow disengagement of the contactor ...