Emergency power systems are a type of device, which may include lighting, generators and other apparatus, to provide backup resources in a crisis or when regular systems fail. They find uses in a wide variety of settings from residential homes to hospitals, scientific laboraties and modern naval ships. Emergency power systems can rely on generators or uninterruptible power supplies. A physician visiting the sick in a hospital. ... An electrical generator is a device that produces electrical energy from a mechanical energy source. ... An uninterruptible power supply, or UPS, is a device or system that maintains a continuous supply of electric power to certain essential equipment that must not be shut down unexpectedly. ...

History

Emergency power systems were used as early as World War II on naval ships. In combat, a ship may lose the function of its steam engines, which power the steam driven turbines for the generator. In such a case, one or more diesel engine(s) are used to drive back-up generators. Early transfer switches relied on manual operation; two switchs would be placed horizontally, in line and the "on" position facing each other. a rod is placed in between. In order to operate the switch one source must be turned off, the rod moved to the other side and the other source turned on. Combatants Allies: Soviet Union United Kingdom United States and others Axis Powers: Germany Italy Japan and others Commanders Winston Churchill Franklin Roosevelt Joseph Stalin Adolf Hitler Benito Mussolini Hideki Tojo Casualties Military dead: 17,000,000 Civilian dead: 33,000,000 Total dead: 50,000,000 Military dead: 8,000... A steam engine is a heat engine that makes use of the thermal energy that exists in steam, converting it to mechanical work. ... WWII era steam turbine used for ship propulsion. ... An electrical generator is a device that produces electrical energy from a mechanical energy source. ... A Diesel engine built by MAN AG in 1906 Rudolf Diesels 1893 patent on his engine design The diesel engine is a type of internal combustion engine; more specifically, it is a compression ignition engine, in which the fuel is ignited by being suddenly exposed to the high temperature... Transfer switches allow switching from a primary power source to a secondary or tertiary power source and are employed in some electrical power distribution systems. ...

Operation in buildings

Utility power (known as normal power) can be lost due to downed lines, malfunctions at a sub-station, planned blackouts or in extreme cases a grid-wide failure. In a modern building, most emergency power sytstems rely on a diesel engine driven generator, although smaller buildings may use a gasoline engine driven generator. An automatic transfer switch is used to tie the emergency power in. One side is connected to both the normal power feed and the emergency power feed; and the other side is connected to the load designated as emergency. If no electricity comes in on the normal side, the transfer switch uses a solenoid to throw a triple pole, single throw switch. This switches the feed from normal to emergency power. The loss of normal power also triggers a battery operated starter system to start the generator, similar to using a car battery to start an engine. Once the transfer switch is switched and the generator starts, the building's emergency power comes back on (after going off when normal power was lost.) Emergency lighting (also known as egress lighting) is almost always on a building's emergency power system. Unlike emergency lights, emergency lighting is not a type of light fixture, it is a pattern of the building's normal lights that provides a path of lights to allow for safe eixt in case of an emergency or light up service areas such as mechanical rooms and electric rooms. Emergency lighting also includes exit signs. Fire alarm systems and the electric motor pumps for the fire sprinklers is almost always on emergency power. Other equipment that may be on emergency power can include smoke isolation dampers, smoke evacuation fans, handicap doors and outlets in service areas. Hospitals use emergency power outlets to power life support systems and monitoring equipment. Some buildings may even use emergency power as part of normal operations, such as a theatre using it to power show equipment because "the show must go on." Rolling blackout refers to an intentionally-engineered electrical power outage, caused by insufficient available resources to meet prevailing demand for electricity. ... Transmission lines in Lund, Sweden Transmission towers and lines in Coquitlam, British Columbia. ... A Diesel engine built by MAN AG in 1906 Rudolf Diesels 1893 patent on his engine design The diesel engine is a type of internal combustion engine; more specifically, it is a compression ignition engine, in which the fuel is ignited by being suddenly exposed to the high temperature... An electrical generator is a device that produces electrical energy from a mechanical energy source. ... Gasoline engine (also referred to as petrol engine or Otto engine) invented at the end of the 19th century by German engineer Nikolaus Otto is a type of internal combustion engine which is often used for automobiles, aircraft, small mobile vehicles such as lawnmowers or motorcycles, and outboard motors for... Image:Turbo starter. ... An emergency is a situation that poses an immediate threat to human life or serious damage to property. ... A well-designed fire exit sign should be easily seen, even if visibility is poor. ... A fire alarm system is an active fire protection system that controls all the fire alarms in a building. ... This typical sprinkler head will spray water into the room if sufficient heat reaches the bulb and causes it to shatter. ... Life support, in the medical field, refers to a set of therapies for preserving a patients life when essential body systems are not functioning sufficiently to sustain life unaided. ...

Electrionic device protection

Computers, communication networks and other modern electronic devices depend on a steady stream of power to continue to operate. If the source voltage drops significantly or drops out completely these devices will fail, even if it is for a fraction of a second. Because of this, even a generator back-up does not provide protection because of the start-up time envolved. To achieve this protection an uninterruptible power supply (UPS) is used. UPS systems can be local or building wide. Local UPS's are a small box that fits under a desk or a telecom rack and powers a small number of devices. A building wide UPS is a large bank of batterties located in an electric room or outside near the main feed. It directly feeds a system of outlets designated as UPS feed and can power a large number of devices. An uninterruptible power supply, or UPS, is a device or system that maintains a continuous supply of electric power to certain essential equipment that must not be shut down unexpectedly. ...

Structure and operation in utility stations

Diagram of a redundant power supply system.

In recent years, large units of a utility power station are usually designed on a unit system basis in which the required devices, including the boiler, the turbine generator unit, and its power (step up) and unit (auxiliary) transformer are solidly connected as one unit. A less common set-up consists of two units grouped together with one common station auxiliary. As each turbine generator unit has its own attached unit auxiliary transformer, it is connected to the circuit automatically. For starting the unit, the auxiliaries are supplied with power by another unit (auxiliary) transformer or station auxiliary transformer. The period of switching from the first unit transformer to the next unit is designed for automatic, instantaneous operation in times when the emergency power system needs to kick in. It is imperative that the power to unit auxiliaries not fail during a station shutdown (an occurrence known as black-out when all regular units temporarily fail) Instead, during shutdowns the grid is expected to remain operational. When problems occur, it is usually due to reverse power relays and frequency-operated relays on grid lines due to severe grid disturbances. Under these circumstances, the emergency station supply must kick in to avoid damage to any equipment and to prevent hazardous situations such as the release of hydrogen gas from generators to the local environment. Image File history File links Download high resolution version (2060x1455, 303 KB) Summary Drawn from memory; scanned and uploaded in PNG format. ... Image File history File links Download high resolution version (2060x1455, 303 KB) Summary Drawn from memory; scanned and uploaded in PNG format. ... Three-phase pole-mounted step-down transformer. ... For other uses, see Blackout (disambiguation). ... GRID can refer to : GRID computing short for gay-related immune deficiency, a former name for AIDS. See also homosexuality and medical science General Repository for Interaction Datasets, a database of biological interactions hosted at Mount Sinai Hospital in Toronto, Canada This is a disambiguation page — a navigational aid which... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ...

Fueling the emergency power system

For a 230 V AC emergency supply system, a central battery system with controls, located in the power station building itself, is used to avoid long electric supply leads. This central battery system consists of lead-acid battery cell units to make up 240 V DC as well as a few more stand-by cells, each with its own battery charging unit. Also needed are an inverter unit capable of receiving 230 V AC and an automatic switch-less system that is able to signal to and activate the emergency supply circuit in case of failure of AC 230 V station supply. A sealed lead acid battery. ...

See also

• Emergency light