PEC电气工程专业英语证书考试-电气工程专有名词4

PEC电气工程专业英语证考试-Glossary of Electrical Engineering Terms4 Auto ranging: A DMM that automatically selects the range with the best resolution and accuracy in response to the application. AAC: Amps alternating current AC/DC: A switch designated for use with either Alternating Current (AC) or Direct Current (DC). AC Only: A switch designated for use with Alternating Current (AC) only. AC Power: AC stands for alternating current, which is an electrical current that frequently reverses direction. AC electricity is measured according to its cycles, with one complete cycle being counted each time a given current travels in one direction and then doubles back on itself. An electrical current is able to complete many cycles per second, and is then given its frequency rating based on that number; for example, the typical frequency in North America is 60 hertz (Hz), which indicates that the current is performing 60 cycles per second. AC power is the type of electricity most commonly used in homes and offices, and is extremely versatile because its voltage can be changed through a transformer to suit a variety of transmission needs. ADC: Data converting from analog to digital format. AL/CU: 30A, 50A or 60A receptacles designated for use with aluminum or copper circuit conductors, identified by "AL/CU" stamped on the device. Receptacles without this designation must never be used with aluminum circuit conductors. Active Power: Also known as ‘Real Power’ or simply ‘Power’. Active power is the rate of producing, transfer or using electrical energy. Measured in watts and often-expressed in kW or MW. Adapter: An accessory used for interconnecting non-mating devices or converting an existing device for modified use. Ampere (Amp): The ampere, or amp, is the measure of an electrical current in a given circuit. A single amp is equal to 6,280,000,000,000,000,000 electrons passing a specific point in one second. Amplitude: A non-negative scalar measure of a wave's magnitude of oscillation, that is, the magnitude of the maximum disturbance in the medium during one wave cycle. Analog Meter: A mechanical measuring device using a needle moving across a graduated scale or dial.   Angle: A plug or connector that allows the attached flexible cord to exit at right angles.   Arc Fault: Arcing faults are one of the major causes of these fires. When unwanted arcing occurs, it generates high temperatures that can ignite nearby combustibles such as wood, paper, and carpets. Arcing faults often occur in damaged or deteriorated wires and cords. Some causes of damaged and deteriorated wiring include puncturing of wire insulation from picture hanging or cable staples, poorly installed outlets or switches, cords caught in doors or under furniture, furniture pushed against plugs in an outlet, natural aging, and cord exposure to heat vents and sunlight.   Arc Fault Circuit Interrupter (AFCI): AFCIs are newly-developed electrical devices designed to protect against fires caused by arcing faults in the home electrical wiring. THE FIRE PROBLEM: Annually, over 40,000 fires are attributed to home electrical wiring. These fires result in over 350 deaths and over 1,400 injuries each year1. Arcing faults are one of the major causes of these fires. When unwanted arcing occurs, it generates high temperatures that can ignite nearby combustibles such as wood, paper, and carpets. Arcing faults often occur in damaged or deteriorated wires and cords. Some causes of damaged and deteriorated wiring include puncturing of wire insulation from picture hanging or cable staples, poorly installed outlets or switches, cords caught in doors or under furniture, furniture pushed against plugs in an outlet, natural aging, and cord exposure to heat vents and sunlight. HOW THE AFCI WORKS: Conventional circuit breakers only respond to overloads and short circuits; so they do not protect against arcing conditions that produce erratic current flow. An AFCI is selective so that normal arcs do not cause it to trip. The AFCI circuitry continuously monitors current flow through the AFCI. AFCIs use unique current sensing circuitry to discriminate between normal and unwanted arcing conditions. Once an unwanted arcing condition is detected, the control circuitry in the AFCI trips the internal contacts, thus de-energizing the circuit and reducing the potential for a fire to occur. An AFCI should not trip during normal arcing conditions, which can occur when a switch is opened or a plug is pulled from a receptacle. Presently, AFCIs are designed into conventional circuit breakers combining traditional overload and short-circuit protection with arc fault protection. AFCI circuit breakers (AFCIs) have a test button and look similar to ground fault circuit interrupter (GFCI) circuit breakers. Some designs combine GFCI and AFCI protection. Additional AFCI design configurations are anticipated in the near future. It is important to note that AFCIs are designed to mitigate the effects of arcing faults but cannot eliminate them completely. In some cases, the initial arc may cause ignition prior to detection and circuit interruption by the AFCI. The AFCI circuit breaker serves a dual purpose – not only will it shut off electricity in the event of an “arcing fault”, but it will also trip when a short circuit or an overload occurs. The AFCI circuit breaker provides protection for the branch circuit wiring and limited protection for power cords and extension cords. Single-pole, 15- and 20- ampere AFCI circuit breakers are presently available.   ASTM-1000: Title – Standard Test Methods for Pressure-Sensitive Adhesive-Coated Tapes Used for Electrical and Electronic Applications. ASTM International PUBLICATION DATE: Sep 1, 2004 SCOPE: These test methods cover procedures for testing pressure-sensitive adhesive-coated tapes to be used as electrical insulation. These tapes are classified as follows: Class 1 - Non-elastomeric backings made from materials such as: Paper, flat or creped; Fabric, uncoated or coated; Cellulose ester films; Polyethylene terephthalate (polyester) films; Fluorocarbon polymer films; Composite filament films; Polyamide films; Polyimide films, and Combinations thereof. Class 2 - Elastomeric backings that are characterized by both high stretch and substantial recovery. These backings are made from materials such as: Vinyl chloride and co-polymers; Vinylidene chloride and co-polymers, and Polyethylene and co-polymers. Laminates of Class 1 and Class 2 backings should be tested according to Class 1 test methods. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific hazards see Section 3. The procedures appear in the sections indicated below and in alphabetical order: NOTE 1 - These procedures apply to both Class 1 and Class 2 tapes except as noted above. The values stated in SI units are the standard, unless otherwise noted. If a value for measurement is followed by a value in inch-pound or English units in parentheses, the second value may only be approximate and is for information only. The first stated value is the preferred unit. NOTE 2 - These test methods are similar to IEC 60454-3, but may differ sometimes in some details. This is a fire - test response standard. Automatic Reset: A starter that automatically restarts a new replacement fluorescent lamp after the circuit is energized.   AWG: The abbreviation for American Wiring Gauge, the United States’ standard for measuring the diameter of non-ferrous (non-iron-containing) wire, which is most often applied to household electrical and telephone wiring. Lower-gauge (thicker) wires are capable of carrying more data and energy for longer distances than those with smaller diameters.   Ballast: a. Also called ballast resistor a device, often a resistor, that maintains the current in a circuit at a constant value by varying its resistance in order to counteract changes in voltage. b. a device that maintains the current through a fluorescent or mercury lamp at the desired constant value, sometimes also providing the necessary starting voltage and current.   Beryllium Copper (also High Strength Beryllium Copper): Metal alloy of copper and beryllium. Bayonet: Designed for incandescent lamps having an unthreaded metal shell with two diametrically opposite keyways that mate with the keyways on the lampholder. Pushing down on the bulb and turning it clockwise in the lampholder locks the bulb in place.   Candelabra: A small screw-base threaded lampholder designed for candelabra-base incandescent lamps commonly used in chandeliers, night lights, and ornamental lighting. Cat III: Equipment in fixed installations. Example: Installation in buildings, from main fuse box to wall outlet. Catalyst: A substance that accelerates the rate of a chemical reaction. Calibration: Zeroing of an instrument to a known standard. Capacitance: Ability of a component to hold an electrical charge, usually stated in microfarads. Capacitor: Electronic component which stores energy and then discharges it; blocks DC and allows AC to pass through. Capstan: 1. Nautical An apparatus used for hoisting weights, consisting of a vertical spool-shaped cylinder that is rotated manually or by machine and around which a cable is woound. 2. A small cylindrical shaft used to drive magnetic tape at a constant speed in a tape recorder. CE Rated: About the CE marking Marking of electrical equipment, machinery, gas appliances and heating boilers within the European Union Electrical equipment, machinery, gas appliances and heating boilers to be marketed within the European Economic Area must bear the CE marking. It is a self declaration but mandatory. CE marking generally requires a Technical Construction File, which forms the basis for the Declaration of Conformity. The Technical Construction File indicates the product's conformity with the directives and includes the test reports for the product. The directives require that the manufacturer is capable of manufacturing products of consistent quality. SGS is a notified body and is able to support you to fulfil the requirements of the CE marking. Advantages of the CE marking This is a declaration by the manufacturer or by an importer located within the European Economic Area that the product complies with the essential health and safety requirements of the relevant EU directives. Products being sold in or, respectively, imported into the European Union have to comply with this EU-directive and, for confirmation, have to carry a visible CE-marking. This applies to more than 80% of all industrial and consumer products. Sale without a CE-marking within the EU is not permitted. Circline:  A four-contact, double-ended lampholder designed for use with tubular, circular fluorescent lamps. CO/ALR:  15A or 20A receptacles designated for use with aluminum or copper circuit conductors, identified by "CO/ALR" stamped on the device. Receptacles without this designation must never be used with aluminum circuit conductors. CP:  Clean Power - Less than 5% harmonic distortion Clamp-on: DMM with jaws that allow it to fit around a conductor to measure AC or DC current without breaking the circuit. Clamping Level: A clamping level is the highest level of voltage that a surge protector will allow an electrical device to reach, before actively diverting excess electricity to a grounding line. Clamping Voltage: The peak voltage that can be measured after a Surge Protective Device has limited or "clamped" a transient voltage surge.  Clamping voltage must be determined by using IEEE Standard C62 testing and evaluated by UL Standard 1449. Clock Hanger: A single, recessed receptacle with a specialized cover plate that provides a hook or other means of supporting a wall clock.   Cold Start: A method of restarting a computer by turning the power back on; often necessary after a power failure or other system interruption. Also known as a Cold Boot. Some Uninterruptible Power Supply units are capable of performing a Cold Start on the computers they are providing with battery backup. Combination: A multiple- gang wallplate with openings in each gang to accommodate different devices.   Compact Fluorescent: A lampholder designed for the Compact Fluorescent Lamps (CFL’s) that are increasingly being used to replace incandescent lamps for energy efficiency.   Conductive: Having the quality or power of conducting heat or electricity or sound; exhibiting conductivity   Contact: A connection between two conductors that allows a flow of current. Continuity: The continuous path for current flow in a closed circuit. Cord Connector: A portable receptacle designed for attachment to or provided with flexible cord, not intended for fixed mounting. Corrosion Resistant: A device constructed of special materials and/or suitably plated metal parts that is designed to withstand corrosive environments. Corrosion resistant devices must pass the ASTM B117-13 five-hundred hour Salt Spray (Fog) Test with no visible corrosion. Cube Tap: An adapter that converts one receptacle opening into multiple openings. Current: The flow of an electrical charge through a conductor; measured in amperes or amps. Current Tap: An adapter designed for medium base lampholders which has one or two receptacle openings. Available with or without integral switch. C22.2 No. 1010.1: Safety Requirements for Electrical Equipment for Measurement, Control and Laboratory Use - Part 1: General Requirements. First edition, 1992. Second Edition, 2003.   CSA C22.2 #42: A Canadian Standards Association document that gives safety requirements for attachment plugs, electrical receptacles, and similar wiring devices.   Data hold: Feature of DMM that allows continued display of the last reading taken, after probes have been removed. Data logging: The practice of recording sequential data, often chronologically. Decora®: Wallplates with Decora-size openings for compatibility with Leviton’s entire line of Decora devices. Available in a variety of multiple-gang configurations. Screwless-design snap-on versions also available. dB (also db and DB): In electronics and communications, a logarithmic expression of the ratio between two signal power, voltage, or current levels.   DBm: Decibels, referenced to one milliwatt.   DC Power:  DC is the abbreviation for direct current, which is a type of electrical current that travels through a circuit in only one direction. Direct current is the type of electrical power that is produced by fuel cells, batteries, and generators equipped with commutators. While DC power was the first type of electricity to be commercially transmitted, it has been widely replaced by alternating current (AC) electricity, and is now used primarily in electrochemical and metal-plating applications. Differential Signaling:  A method of transmitting data electronically over two separate wires, often used to eliminate EMI/RFI. Digital Media Receiver:  A home entertainment device used to connect a home theatre system to a computer network in order to retrieve media files. Dimmer:  An electronic device with either a round knob, slide lever or finger-tip controlled buttons used to dim/brighten incandescent lighting. Available in a variety of wattages; fluorescent version also available. Diode:  An electronic semiconductor device that predominantly allows current to flow in only one direction. Display:  Receptacle with a special cover plate intended for flush mounting on raised floors or walls. DMM: digital multimeter An instrument that uses an LCD typically capable of measuring voltage, current and resistance. Door: A momentary contact switch, usually installed on a doorjamb, that is activated when the door is opened or closed. Double-Contact Recessed: Designed for high-output fluorescent lamps. Double Insulated:  A Class II or double insulated electrical appliance is one which has been designed in such a way that it does not require a safety connection to electrical earth (US: ground). The basic requirement is that no single failure can result in dangerous voltage becoming exposed so that it might cause an electric shock and that this is achieved without relying on an earthed metal casing. This is usually achieved at least in part by having two layers of insulating material surrounding live parts or by using reinforced insulation. In Europe, a double insulated appliance must be labeled "Class II", "double insulated" or bear the double insulation symbol (a square inside another square).   Double-Pole, Single-Throw (DPST):  A switch that makes or breaks the connection of two circuit conductors in a single branch circuit. This switch has four terminal screws and ON/OFF markings. Double-Pole, Double-Throw (DPDT):  A switch that makes or breaks the connection of two conductors to two separate circuits. This switch has six terminal screws and is available in both momentary and maintained contact versions, and may also have a center OFF position. Duplex:  An adapter that provides two female receptacle openings when plugged into a single receptacle opening. Dust Proof:  A device designed so that dust will not interfere with its operation. The IP Suitability Rating designates the degree of protection a device offers against the ingress of foreign objects (e.g. IP 20). Earth / ground: In electrical engineering, the term ground or earth has several meanings depending on the specific application areas. Ground is the reference point in an electrical circuit from which other voltages are measured, a common return path for electrical current (earth return or ground return), or a direct physical connection to the Earth. Edison Base: An internally-threaded lampholder, with the inner shell approx. 1" in diameter. Designed for widely-used standard medium base lamps. Electrical Conductivity: When a voltage is applied across a substance, an electric current will only flow if the substance conducts electricity Electrical resistance: is a measure of the degree to which an object opposes an electric current through it, measured in ohms. Its reciprocal quantity is electrical conductance measured in siemens. Assuming a uniform current density, an object's electrical resistance is a function of both its physical geometry and the resistivity of the material it is made from Electrolier: Similar to the Edison Medium Base lampholder, but with a smaller outer diameter. Electromigration: The transport of material caused by the gradual movement of the ions in a conductor due to the momentum transfer between conducting electrons and diffusing metal atoms. The effect is important in applications where high direct current densities are used, such as in microelectronics and related structures. As the structure size in electronics such as integrated circuits (ICs) decreases, the practical significance of this effect increases. Epoxy: Any of various usually thermosetting resins capable of forming tight cross-linked polymer structures characterized by toughness, strong adhesion, and low shrinkage, used especially in surface coatings and adhesives. Epoxy Glue: A thermosetting resin; used chiefly in strong adhesives and coatings and laminates.   Equalization : Technique used to reduce distortion and compensate for signal loss (attenuation) over long distance communication lines.   EN 61326:1998 : Electrical equipment for measurement, control, and laboratory use—EMC requirements. Explosion Proof: A device constructed to meet the requirements of hazardous locations as defined by the National Electrical Code, NFPA-70. Fan Hanger: A single receptacle with a specialized cover plate that provides a hook or other means of supporting a wall fan. Farad