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Fire Alarms
A fire alarm system is a building system designed to detect, alert occupants, and alert emergency forces of the presence of fire, smoke, carbon monoxide, or other fire-related emergencies. Fire alarm systems are required in most commercial buildings. They may include smoke detectors, heat detectors, and manual fire alarm activation devices (Manual fire alarm activation, pull stations). All components of a fire alarm system are connected to a fire alarm control panel. Fire alarm control panels are usually found in an electrical or panel room. Fire alarm systems generally use visual and audio signalization to warn the occupants of the building. Some fire alarm systems may also disable elevators, which are unsafe to use during a fire under most circumstances. Design Fire alarm systems are designed after fire protection requirements in a location are established, which is usually done by referencing the minimum levels of security mandated by the appropriate model building code, in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BS 5839 Part 1
BS 5839 Part 1 ''Fire detection and fire alarm systems for buildings – Part 1: Code of practice for design, installation, commissioning and maintenance of systems in non-domestic premises'' is a standard published by the British Standards Institution. BS 5839-1:2017 supersedes BS 5839-1:2013, which has been withdrawn. It s the first of 9 parts in a series on national standards relating to fire alarms. Purpose BS 5839 Part 1 provides recommendations for the planning, design, installation, commissioning and maintenance of fire detection and fire alarm systems for non-domestic premises. Recommendations for fire detection and fire alarm systems in domestic premises are given in BS 5839-6. It does not recommend whether or not a fire detection and alarm system should be installed in any given premises, nor does it provide any exceptions for non-domestic premises which are under construction. The term "fire detection and fire alarm systems" is a fairly wide definition, including small ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heat Detector
A heat detector is a fire alarm device designed to respond when the convected thermal energy of a fire increases the temperature of a heat sensitive element. The thermal mass and conductivity of the element regulate the rate flow of heat into the element. All heat detectors have this thermal lag. Heat detectors have two main classifications of operation, "rate-of-rise" and "fixed temperature". The heat detector is used to help in the reduction of property damage. Fixed temperature heat detectors This is the most common type of heat detector. Fixed temperature detectors operate when the heat sensitive eutectic alloy reaches the eutectic point changing state from a solid to a liquid. Thermal lag delays the accumulation of heat at the sensitive element so that a fixed-temperature device will reach its operating temperature sometime after the surrounding air temperature exceeds that temperature. The most common fixed temperature point for electrically connected heat detectors is . ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Input Device
In computing, an input device is a piece of equipment used to provide data and control signals to an information processing system, such as a computer or information appliance. Examples of input devices include keyboards, computer mice, scanners, cameras, joysticks, and microphones. Input devices can be categorized based on: * modality of output (e.g., mechanical motion, audio, visual, etc.) * whether the output is discrete (e.g., pressing of key) or continuous (e.g., a mouse's position, though digitized into a discrete quantity, is fast enough to be considered continuous) * the number of degrees of freedom involved (e.g., two-dimensional traditional mice, or three-dimensional navigators designed for CAD applications) Keyboard A keyboard is a human interface device which is represented as a matrix of buttons. Each button, or key, can be used to either input an alphanumeric character to a computer, or to call upon a particular function of the computer. It acts as th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Generator
In electricity generation, a generator, also called an ''electric generator'', ''electrical generator'', and ''electromagnetic generator'' is an electromechanical device that converts mechanical energy to electrical energy for use in an external circuit. In most generators which are rotating machines, a source of kinetic power rotates the generator's shaft, and the generator produces an electric current at its output terminals which flows through an external circuit, powering electrical loads. Sources of mechanical energy used to drive generators include steam turbines, gas turbines, water turbines, internal combustion engines, wind turbines and even hand cranks. Generators produce nearly all of the electric power for worldwide electric power grids. The first electromagnetic generator, the Faraday disk, was invented in 1831 by British scientist Michael Faraday. The reverse conversion of electrical energy into mechanical energy is done by an electric motor, and motors and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lead–acid Battery
The lead–acid battery is a type of rechargeable battery first invented in 1859 by French physicist Gaston Planté. It was the first type of rechargeable battery to be invented. Compared to modern rechargeable batteries, lead–acid batteries have relatively low energy density. Despite this, they are able to supply high surge currents. These features, along with their low cost, make them attractive for use in motor vehicles in order to provide the high current required by starter motors. Lead–acid batteries suffer from relatively short cycle lifespan (usually less than 500 deep cycles) and overall lifespan (due to the ''double sulfation'' in the discharged state), as well as long charging times. As they are not as expensive when compared to newer technologies, lead–acid batteries are widely used even when surge current is not important and other designs could provide higher energy densities. In 1999, lead–acid battery sales accounted for 40–50% of the value from batteries ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Branch Circuit
Electrical wiring is an electrical installation of cabling and associated devices such as switches, distribution boards, sockets, and light fittings in a structure. Wiring is subject to safety standards for design and installation. Allowable wire and cable types and sizes are specified according to the circuit operating voltage and electric current capability, with further restrictions on the environmental conditions, such as ambient temperature range, moisture levels, and exposure to sunlight and chemicals. Associated circuit protection, control, and distribution devices within a building's wiring system are subject to voltage, current, and functional specifications. Wiring safety codes vary by locality, country, or region. The International Electrotechnical Commission (IEC) is attempting to harmonise wiring standards among member countries, but significant variations in design and installation requirements still exist. Wiring methods Materials for wiring interior ele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alternating Current
Alternating current (AC) is an electric current that periodically reverses direction and changes its magnitude continuously with time, in contrast to direct current (DC), which flows only in one direction. Alternating current is the form in which electric power is delivered to businesses and residences, and it is the form of electrical energy that consumers typically use when they plug kitchen appliances, televisions, Fan (machine), fans and electric lamps into a wall socket. The abbreviations ''AC'' and ''DC'' are often used to mean simply ''alternating'' and ''direct'', respectively, as when they modify ''Electric current, current'' or ''voltage''. The usual waveform of alternating current in most electric power circuits is a sine wave, whose positive half-period corresponds with positive direction of the current and vice versa (the full period is called a ''wave cycle, cycle''). "Alternating current" most commonly refers to power distribution, but a wide range of other appl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Command (computing)
In computing, a command is an instruction received via an external Interface (computing), interface that directs the behavior of a computer program. Commonly, commands are sent to a program via a command-line interface, a scripting language, script, a network protocol, or as an event triggered in a graphical user interface. Many commands support arguments to specify input and to modify default behavior. Terminology and syntax varies but there are notable common approaches. Typically, an option or a flag is a name (without Whitespace character, whitespace) with a prefix such as dash or Slash (punctuation), slash that modifies default behavior. An option might have a required value that follows it. Typically, flag refers to an option that does not have a following value. A parameter is an argument that specifies input to the command and its meaning is based on its position in the command line relative to other parameters; generally ignoring options. A parameter can specify anything ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fire Alarm Control Panel
A fire alarm control panel (FACP), fire alarm control unit (FACU), fire indicator panel (FIP), or simply fire alarm panel is the controlling component of a fire alarm system. The panel receives information from devices designed to detect and report fires, monitors their operational integrity, and provides for automatic control of equipment, and transmission of information necessary to prepare the facility for fire based on a predetermined sequence. The panel may also supply electrical energy to operate any associated initiating device, notification appliance, control, transmitter, or relay. There are four basic types of panels: coded panels, conventional panels, addressable panels, and multiplex systems. Coded panels Coded panels were the earliest type of central fire alarm control, and were made during the 1800s to the 1970s. A coded panel is similar in many ways to a modern conventional panel (described below), except each zone was connected to its own code wheel, which, depe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fire Alarm Systems 4
Fire is the rapid oxidation of a fuel in the exothermic chemical process of combustion, releasing heat, light, and various reaction products. Flames, the most visible portion of the fire, are produced in the combustion reaction when the fuel reaches its ignition point temperature. Flames from hydrocarbon fuels consist primarily of carbon dioxide, water vapor, oxygen, and nitrogen. If hot enough, the gases may become ionized to produce plasma. The color and intensity of the flame depend on the type of fuel and composition of the surrounding gases. Fire, in its most common form, has the potential to result in conflagration, which can lead to permanent physical damage. It directly impacts land-based ecological systems worldwide. The positive effects of fire include stimulating plant growth and maintaining ecological balance. Its negative effects include hazards to life and property, atmospheric pollution, and water contamination. When fire removes protective vegetation, heavy r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
