1、NEMA IA*2.1 946470247 0506198758NEMA STANDARDS PUBLICATION NO.IA 2.1-1994IEC PUBLICATION NO.1131-1号ProgrammableControllers-Part 1:GeneralInformationNEMANATIONAL ELECTRICAL MANUFACTURERS ASSOCIATION2101 L STREET,N.W.,WASHINGTON,D.C.20037Copyright por National Electrical Manufacturers AssociationSun M
2、ay 05 07:36:32 2002NEMA Standards Publication No.IA 2.1-1993(R2000)/IEC 61131-1Programmable Controllers-General InformationPublished by:National Electrical Manufacturers Association1300 North 17th Street,Suite 1847Rosslyn,VA22209 Copyright 2000 by the National Electrical Manufacturers.All rights inc
3、luding translation intoother languages reserved under the Universal Copyright Convention,the Berne Convention forthe Protection of Literary and Artistic Works,and the International and Pan American CopyrightConventions.Copyright por National Electrical Manufacturers AssociationSun May 05 07:36:32 20
4、02NEMA IA*2.194647024?0506200136IAA2.1-1994IEC1131-1PageiTABLE OF CONTENTSPageReferenced Standards.dAmendments.1Copyright por National Electrical Manufacturers AssociationSun May 05 07:36:32 2002NEMA IA*2.1 9464702470506201072IA2.1-1994IEC1131-1Page ilFOREWORDThis Standards Publication is a NEMA Ado
5、ptive Standard based on Part 1 of IEC 1131,Programmable Controllers.This Standards Publication was prepared by a technical committee of the NEMA Automation Products and SystemsSection.It was approved in accordance with the bylaws of NEMA and supersedes NEMA Standards Publication ICS 3-1988,Part3-304
6、.This Standards Publication provides practical information concerning ratings,construction,test,performance andmanufacture of industrial control equipment.These standards are used by the electrical industry to provide guidelines forthe manufacture and proper application of reliable products and equi
7、pment and to promote the benefits of repetitivemamufacturing and widespread product availability.NEMA Standards represent the result of many years of research,investigation and experience by the members ofNEMA,its predecessors,its Sections and Committees.They have been developed through continuing c
8、onsultation amongmanufacturers,users and national engineering societies and have resulted in improved serviceability of electrical productuwith economies to manufacturers and users.One of the primary purposes of this Standards Publication is to encourage the production of reliable control equipmentw
9、hich,in itself,finctions in accordance with these accepted standards.Some portions of these standards,such as electricalspacings and interrupting ratings,have a direct bearing on safety;almost all of the items in this publication,when appliedproperly,contribute to safety in one way or another.Proper
10、ly constructed industrial control equipment is,however,only one factor in minimizing the hazards which maybe associated with the use of electricity.The reduction of hazard involves the joint efforts of the various equipmentmanufacturers,the system designer,the installer and the user.Information is p
11、rovided herein to assist users and others inthe proper selection of control equipment.The industrial control manufacturer has limited or no control over the following factors which are vital to a safeinstallation:a.environmental conditionsb.system designc.equipment selection and applicationd.install
12、atione.operating practicesf.maintenanceThis publication is not intended to instruct the user of control equipment with regard to these factors except insofar assuitable equipment to meet needs can be recognized in this publication and some application guidance is givenThis Standards Publication is n
13、ecessarily confined to defining the construction requirements for industrial controlequipment and to providing recommendations for proper selection for use under normal or certain specific conditions.Sinceany piece of industrial control equipment can be installed,operated and maintained in such a ma
14、nner that hazardousconditions may result,conformance with this publication does not by itself assure a safe installation.When,however,equipment conforming with these standards is properly selected and is installed in accordance with the National ElectricalCode and properly maintained,the hazards to
15、persons and property will be reducedTo continue to serve the best interests of users,NEMA is actively cooperating with other standardization organizationsin the development of simple and more universal metrology practices.In this Standards Publication,the U.S.customary unitsare gradually being suppl
16、emented by those of the modernized metric system known as the International Systems of Units(SI).This tramsition involves no changes in standard dimensions,tolerances,or performance specificationsCopyright por National Electrical Manufacturers AssociationSun May 05 07:36:32 2002NEMA IA*2.19464702470
17、506202T0可A2.1-19941E01131-1Page相NEMA Standards Publications are subject to periodic review.They are revised frequently to reflect user input and tomeet changingionsand chical progress.Users should secue the latest editions.See the postal retur card anachedto the front cover of this Standards Publica
18、tion for the proper procedure to obain revision service for your copy of thepublication.Proposed revisions to this Standards Publication should be submitted to:Engineering DepartmentNational Electrical Manufacturers Association2101 L Street,N.W.Washington,DC 20037Copyright por National Electrical Manufacturers AssociationSun May0507:36:322002