1、ElectricalTerms and DefinitionsCEMA 110-1995PDF Version - 2002CEMASTANDARDNO. 110ISBN 1-891171-51-8Conveyor EquipmentManufacturers AssociationFor Information on Company Membershipvisit the CEMA Web Site athttp:/www.cemanet.orgConveyorChainCEMA ORGANIZATIONAL CHARTControls PalletizersMeet in March an
2、d/or SeptemberConferenceStrategic PlanningInsuranceMeetingsMembershipPublic RelationsStatisticsSafety SteeringFinance and BudgetPast PresidentsBulk HandlingSectionCommitteesUnit HandlingSectionEngineering ConferenceConveyor ChainPerformance TerminologyUnit Handling StandardsIdlersPulleysBeltSystemsS
3、crewConveyorsBeltManualAccessoriesSafety ControlsTerms andDefinitionsInternationalStandardsMeets Each JuneScrewConveyorsBulk HandlingComponentsand SystemsGeneral Bulk Handling SectionBulkAccessoriesUnit Handling Conveying SectionCOMMITTEES BOARD OF DIRECTORS OFFICERSSAFETY NOTICEThe Conveyor Equipme
4、nt Manufacturers Association has developed Industry Standard Safety Labelsfor use on the conveying equipment of its member companies.The purpose of the labels is to identify common and uncommon hazards, conditions, and unsafepractices which can injure, or cause the death of, the unwary or inattentiv
5、e person who is workingat or around conveying equipment.The labels are available for sale to member companies and non-member companies.A full description of the labels, their purpose, and guidelines on where to place the labels on typicalequipment, has been published in CEMAs Safety Label Brochure N
6、o. 201. The Brochure is availablefor purchase by members and non-members of the Association. Safety Labels and Safety LabelPlacement Guidelines, originally published in the Brochure, are also available free on the CEMAWeb Site at http:/www.cemanet.org/Safety/PLEASE NOTE: Should any of the safety lab
7、els supplied by the equipment manufacturer becomeunreadable for any reason, the equipment USER is then responsible for replacement and locationof these safety labels.Replacement labels and placement guidelines can be obtained by contacting your equipment supplieror CEMA.DISCLAIMER The information pr
8、ovided in this document is advisory only. These recommendations are provided by CEMA in the interest of promoting safety in the work place. These recommendations are general in nature and are not intended as a substitute for a thorough safety program. Users should seek the advise, supervision or con
9、sultation of qualified engineers or other safety professionals. Any use of this document, the information contained herein, or any other CEMA publication may only be made with the agreement and understanding that the user and the users company assume full responsibility for the design, safety, speci
10、fications, suitability and adequacy of the system component, or mechanical or electrical device designed or manufactured using this information. The user and the users company understand and agree that CEMA, its member companies, its officers, agents and employees shall not be liable in any manner u
11、nder any theory of liability for the user or users reliance on these recommendations. The users and the users company agree to release, hold harmless and indemnify CEMA, its member companies, successors, assigns, officers, agents and employees from any and all claims of liability, costs, fees (inclu
12、ding attorneys fees), or damages arising in any way out of the use of this information. CEMA and its member companies, successors, assigns, officers, agents and employees make no representations or warranties whatsoever, either express or implied, about the information contained in this document, in
13、cluding, but not limited to, representations or warranties that the information and recommendations contained herein conform to any federal, state or local laws, regulations, guidelines or ordinances. FOREWORD AND ACKNOWLEDGMENTSThis publication, Electrical Terms and Definitions has been prepared by
14、 the Electrical Terms and DefinitionsCommittee of the CEMA Engineering Conference. The objective and purpose for publishing this standardinclude:A. Encourage uniform usage and understanding of electrical and electronics terminology utilizedin the conveying field.B. Assist in providing appropriate in
15、formation for the selection and application of proper engineeringpractice in the field of materials handling as accomplished through usage of conveyor equipment.C. Provide a source or basis of information related to characteristics, features and conditionsinherent to the practices of materials handl
16、ing through usage of conveying equipment.Throughout this standard, preferred terms are followed by their definitions. Alternate terms in commonusage are listed and cross-indexed back to the preferred term in each case.Utilitization of Electrical Terms and Definitions, as published herein, is complet
17、ely voluntary. This publicationmay be adhered to in its entirety, in part, or not at all, dependent upon agreement of the parties involved.For definitions of terminology which are not included herein, review the following references:A. CEMA Terms and Definitions (Standard No. 102).B. CEMA Classifica
18、tion and Definitions of Bulk Materials (Book No. 550).C. CEMA Conveyor Performance Terminology (Standard No. 705).D. ANSI/ASME B20.1, Safety Standard for Conveyors and Related Equipment.Legal terms and definitions are not within the scope of this publication.The Conveyor Equipment Manufacturers Asso
19、ciation gratefully acknowledges the advice, assistanceand constructive criticisms afforded by the members of the committee and their companies. Without theirrespective contributions, preparation of this standard would not been have possible.CONVEYOR EQUIPMENT MANUFACTURERS ASSOCIATION6724 Lone Oak B
20、lvd.Naples, Florida 34109(239) 514-3441Web SIte: http:/www.cemanet.orgAALTERNATING CURRENT CONTACTOR - a contactorfor the specific purpose of establishing and interruptingan alternating current power circuit.AMBIENT CONDITIONS - the condition of the atmo-sphere adjacent to the electrical apparatus.
21、The spe-cific reference may apply to temperature, contamination,humidity, etc.AMBIENT TEMPERATURE - the temperature of themedium such as air, water, or earth into which the heatof the equipment is dissipated. The temperature of thesurrounding cooling medium, such as gas or liquids,which comes into c
22、ontact with the heated parts of theapparatus. Notes:(a) For self-ventilated equipment, the ambienttemperature is the average (*) temperature of the air inthe immediate neighborhood of the equipment.(b) For air- or gas- cooled equipment with forcedventilation or secondary water cooling, the ambientte
23、mperature is taken as the temperature of the in-goingair or cooling gas.(c) For self-ventilated enclosed (including oil-immersed) equipment considered as a complete unit,the ambient temperature is the average (*) temperatureof the air outside of the enclosure in the immediateneighborhood of the equi
24、pment.(*) The average of temperature readings atseveral locations.AMPACITY - current-carrying capacity expressed inamperes.ANALOG SIGNAL - a continuous signal that dependsdirectly on magnitude (voltage or current) to representsome condition. For example, a voltage could representthe speed of a motor
25、 (e.g. 5 V corresponding to 200rpm; 10 V corresponding to 400 rpm, etc.).ANALOG-TO-DIGITAL CONVERTER - circuit thatconverts a continuous signal that depends directly onmagnitude to a discrete signal that represents magnitudeby a coded number. For example: a 0 through 10 Vsignal can be represented by
26、 a set of binary signalswhose numerical values from 0 through 4095 areproportional to the voltage (e.g., 0V=0 5V=204810V=4095).ANTIHUNT - see Damping.ANTI-PLUGGING PROTECTION - the effect of a controlfunction or a device which operates to prevent applicationof counter-torque by the motor until the m
27、otor speed hasbeen reduced to an acceptable value.APPLICATION TESTS - those tests performed by amanufacturer to determine those operatingcharacteristics which are not necessarily established bystandards but which are of interest in the application ofdevices.AUTOMATIC RESET - a function which operate
28、s toautomatically reestablish specific conditions.AUXILIARY CONTACTS - auxiliary contacts of aswitching device are contacts in addition to the main-circuit contacts and function with the movement of thelatter.AUXILIARY DEVICE - any electrical device other thanmotors and motor starters necessary to f
29、ully operate themachine or equipment.BBACKPLATE - see SUBPANEL.BAR CODE - an automatic identification technologywhich encodes information into an array of varying widthparallel rectangular bars and spaces.BAR CODE LABEL - a label which carries a bar codesymbol and is suitable to be affixed to an art
30、icle.BAR CODE READER - see SCANNER - a device toretrieve data by passing a wand scanner or sensor acrossa set of variable width lines or bars printed on a label.BARRIER - a partition for the insulation or isolation ofelectric circuits or electric arcs.BAUD - the measure of the number of bits per sec
31、ondthat can be transmitted in a data communicationssystem.BCD - an abbreviation for Binary Coded Decimal. BCDis a system of representing decimal data in binary code.For example: in BCD, 16 is represented as 0001 (for 1)and 0110 (for 6).BINARY - a numbering system that uses a base number,or radix, of
32、 two. There are two digits (1 and 0) in thebinary system.BIT - an acronym for Binary digIT. A BIT can assumeone of two possible states: ON or OFF; HIGH or LOW,Logic 1 or Logic 0; etc.BIT CLEAR - a special function that clears a bit in aholding register or an output register. When a Bit Clear(BC) coi
33、l is energized, the designated bit is cleared to alogic 0. When the BC is de-energized, the designatedbit is unaffected.BIT FOLLOW - a special function coil that, whenenergized, sets the bit for which the Bit Follow (BF) isprogrammed. When the BF coil is de-energized, thedesignated bit clears to a l
34、ogic 0.BIT PICK - a contact used to determine the state ofindividual bits in registers.BLOCK DIAGRAM - a diagram showing the relationshipof separate sub-units (blocks) in the control system. Ablock made up of a group of interconnected blocks, eachof which represents a device or subsystem.BONDING CON
35、DUCTOR - one which serves to connectexposed metal surfaces together.BRANCH CIRCUIT - the portion of a wiring systemextending beyond the final overcurrent device protectingthe circuit. (A device not approved for branch-circuitprotection, such as a thermal cutout or motor overloadprotective device, is
36、 not considered as the overcurrentdevice protecting the circuit.)BREAK - to open an electrical circuit.BREAK RATING - the value of current for which a contactassembly is rated for opening a circuit repeatedly at aspecified voltage and under specified operatingconditions.BUS - one or more conductors
37、used for transmittingsignals or power from one or more sources to one ormore destinations.(a) A set of power supply leads, or(b) A conductor which provides multipleconnections.CCAM - machine part or component that applies force toswitch actuator causing actuator to move as intended.CAM TRACK - dista
38、nce from switch mounting surfaceto a specified point on actuator.CAPTIVE SCREW - screw-type fastener that is retainedin some manner when unscrewed and cannot easily beseparated from the part it secures.CARRYOVER PERIOD - the maximum time of powerloss during which a system will remain within specifie
39、dlimits of performance.CHAIN - to program two or more functions as a groupso that the group operates as a single function withexpanded capabilities. For example: Drum controllersmay be chained to expand the number of steps beyondthe individual 128 step maximum.CHASSIS - sheet-metal box, frame, or si
40、mple plate onwhich electronic components and their associatedcircuitry can be mounted.CIRCUIT BREAKER - a device designed to open andclose a circuit by non-automatic means, and to open thecircuit automatically on a predetermined overload ofcurrent, without injury to itself when properly applied with
41、its rating.CIRCUIT INTERRUPTER - a non-automatic manuallyoperated device designed to open, under abnormalconditions, a current-carrying circuit without injury toitself.CLEARANCE - the shortest distance through air betweenconducting parts, or between a conducting part and theouter surface of the insu
42、lating enclosure.CLOCK - a device that generates periodic signals forsynchronization or timing.CMOS - an abbreviation for Complimentary Metal OxideSemiconductor. A family of very low-power, high-speedintegrated circuits.CODE READER - see BAR CODE READER.COMBINATION CONTROLLER - 600 volts or less * -
43、 afull magnetic or semi-magnetic controller with additionalexternally operable disconnecting means contained in acommon enclosure. The disconnecting means may bea circuit breaker or a disconnect switch.(*) Combination starters are specific forms ofcombination controllers.COMBINATION STARTER - a magn
44、etic starter havinga manually operated disconnecting means built into thesame enclosure with the magnetic contactor andoverload device.CONDUCTING PARTS (LIVE PARTS) - those partswhich are designed to carry current.CONNECTION DIAGRAM - see WIRING DIAGRAM.CONSTRUCTION DIAGRAM - a diagram that showsthe
45、 physical arrangement of parts, such as wiring, buses,resistor units, and so forth.Example: A diagram showing the arrangement ofgrids and terminals in a grid-type resistor.CONTACTOR - a two-state (on-off) device for repeatedlyestablishing and interrupting an electric power circuit.Interruption is ob
46、tained by introducing a gap or a verylarge impedance.CONTACTS - conducting parts which complete orinterrupt a circuit.CONTACTS (AUXILIARY) (SWITCHING DEVICE) -contacts in addition to the main-circuit contacts thatfunction with the movement of the latter.CONTACTS (NON-OVERLAPPING) - combination oftwo
47、 sets of contacts, actuated by a common means, eachset closing in one of two positions, and so arranged,that the contacts of one set open before the contacts ofthe other set close.CONTACTS (OVERLAPPING) - combination of two setsof contacts, actuated by a common means, each setclosing in one of two p
48、ositions, and so arranged that thecontacts of one set open after the contacts of the otherset have been closed.CONTINUOUS RATING - the maximum constant loadthat can be carried continuously without exceedingestablished temperature-rise limitations under prescribedconditions of test and within the lim
49、itations of establishedstandards. The rating which defines the substantiallyconstant load which can be carried for an indefinitelylong time.CONTROL - the methods and means of governing theperformance of any electric apparatus, machine orsystem.CONTROL CIRCUIT (INDUSTRIAL CONTROL) - thecircuit that carries the electric signals directing theperformance of the controller but does not carry the mainpower circuit.CONTROL STATION (Local - Remote) - location atwhich actuators are placed for the purpose of starting,stopping, reversing, or otherwise controlling the conveyoror system of conve
