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Static Transfer Switch
A transfer switch is an electrical switch that switches a load between two sources. Some transfer switches are manual, in that an operator effects the transfer by throwing a switch, while others are automatic and trigger when they sense one of the sources has lost or gained power. An ''Automatic Transfer Switch'' (ATS) is often installed where a backup generator is located, so that the generator may provide temporary electrical power if the electricity distribution, utility source fails. Operation of a transfer switch As well as transferring the load to the backup generator, an ATS may also command the backup generator to start, based on the voltage monitored on the primary supply. The transfer switch isolates the backup generator from the electric utility when the generator is on and providing temporary power. The control capability of a transfer switch may be manual only, or a combination of automatic and manual. The switch transition mode (see below) of a transfer switch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wiring Diagram Of 3-phase Transfer Switch
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] |
Switch
In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit, interrupting the electric current or diverting it from one conductor to another. The most common type of switch is an electromechanical device consisting of one or more sets of movable electrical contacts connected to external circuits. When a pair of contacts is touching current can pass between them, while when the contacts are separated no current can flow. Switches are made in many different configurations; they may have multiple sets of contacts controlled by the same knob or actuator, and the contacts may operate simultaneously, sequentially, or alternately. A switch may be operated manually, for example, a light switch or a keyboard button, or may function as a sensing element to sense the position of a machine part, liquid level, pressure, or temperature, such as a thermostat. Many specialized forms exist, such as the toggle swit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electricity Distribution
Electric power distribution is the final stage in the delivery of electricity. Electricity is carried from the transmission system to individual consumers. Distribution substations connect to the transmission system and lower the transmission voltage to medium voltage ranging between and with the use of transformers. ''Primary'' distribution lines carry this medium voltage power to distribution transformers located near the customer's premises. Distribution transformers again lower the voltage to the utilization voltage used by lighting, industrial equipment and household appliances. Often several customers are supplied from one transformer through ''secondary'' distribution lines. Commercial and residential customers are connected to the secondary distribution lines through service drops. Customers demanding a much larger amount of power may be connected directly to the primary distribution level or the subtransmission level. The transition from transmission to distrib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backfeeding
Backfeeding is the flow of electric power in the direction reverse to that of the generally understood or typical flow of power. Depending on the source of the power, this reverse flow may be intentional or unintentional. If not prevented (in the case of unintentional backfeeding) or properly performed (in cases of intentional backfeeding), backfeeding may present unanticipated hazards to electrical grid equipment and service personnel. Types of backfeeding Intentional backfeeding Development and economization of consumer power generation equipment such as wind turbines and photovoltaic systems has led to an increase in the number of consumers that may produce more electrical power than they consume during peak generating conditions. If supported by the consumer's electric utility provider, the excess power generated may be fed back into the electrical grid. This process makes the typical consumer a temporary producer while the flow of electrical power remains reversed. When ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uninterruptible Power Supply
An uninterruptible power supply (UPS) or uninterruptible power source is a type of continual power system that provides automated backup electric power to a electrical load, load when the input power source or mains electricity, mains power fails. A UPS differs from a traditional auxiliary power, auxiliary/emergency power system or standby generator in that it will provide near-instantaneous protection from input power interruptions by switching to energy stored in battery packs, supercapacitors or flywheels. The on-battery run-times of most UPSs are relatively short (only a few minutes) but sufficient to "buy time" for initiating a standby power source or properly shutting down the protected equipment. Almost all UPSs also contain integrated surge protection to shield the output appliances from voltage spikes. A UPS is typically used to protect hardware such as computers, hospital equipment, data centers, telecommunications equipment or other electrical equipment where an unexp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicon-controlled Rectifier
A silicon controlled rectifier or semiconductor controlled rectifier (SCR) is a four-layer solid-state current-controlling device. The name "silicon controlled rectifier" is General Electric's trade name for a type of thyristor. The principle of four-layer p–n–p–n switching was developed by Moll, Tanenbaum, Goldey, and Holonyak of Bell Laboratories in 1956. The practical demonstration of silicon controlled switching and detailed theoretical behavior of a device in agreement with the experimental results was presented by Dr Ian M. Mackintosh of Bell Laboratories in January 1958. The SCR was developed by a team of power engineers led by Gordon Hall and commercialized by Frank W. "Bill" Gutzwiller in 1957. Some sources define silicon-controlled rectifiers and thyristors as synonymous while other sources define silicon-controlled rectifiers as a proper subset of the set of thyristors; the latter being devices with at least four layers of alternating n- and p-type mate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circuit Breaker
A circuit breaker is an electrical safety device designed to protect an Electrical network, electrical circuit from damage caused by current in excess of that which the equipment can safely carry (overcurrent). Its basic function is to interrupt current flow to protect equipment and to prevent fire. Unlike a fuse (electrical), fuse, which operates once and then must be replaced, a circuit breaker can be reset (either manually or automatically) to resume normal operation. Circuit breakers are commonly installed in distribution boards. Apart from its safety purpose, a circuit breaker is also often used as a main switch to manually disconnect ("rack out") and connect ("rack in") electrical power to a whole electrical sub-network. Circuit breakers are made in varying current ratings, from devices that protect low-current circuits or individual household appliances, to switchgear designed to protect high voltage, high-voltage circuits feeding an entire city. Any device which pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
