1、NEMA Standards PublicationNational Electrical Manufacturers AssociationNEMA ICS 2.4-2003 (R2012)NEMA and IEC Devices for Motor Service A Guide for Understanding the DifferencesNEMA ICS 2.4-2003 (R2012) NEMA and IEC Devices for Motor Service A Guide for Understanding the Differences Published by: Nat
2、ional Electrical Manufacturers Association 1300 North 17th Street Rosslyn, Virginia 22209 www.nema.org Copyright 2012 by the National Electrical Manufacturers Association. All rights including translation into other languages, reserved under the Universal Copyright Convention, the Berne Convention f
3、or the Protection of Literary and Artistic Works, and the International and Pan American Copyright Conventions. ICS 2.4-2003 (R2012) Page ii Copyright 2012 by National Electrical Manufacturers Association NOTICE AND DISCLAIMER The information in this publication was considered technically sound by t
4、he consensus of persons engaged in the development and approval of the document at the time it was developed. Consensus does not necessarily mean that there is unanimous agreement among every person participating in the development of this document. The National Electrical Manufacturers Association
5、(NEMA) standards and guideline publications, of which the document contained herein is one, are developed through a voluntary consensus standards development process. This process brings together volunteers and/or seeks out the views of persons who have an interest in the topic covered by this publi
6、cation. While NEMA administers the process and establishes rules to promote fairness in the development of consensus, it does not write the document and it does not independently test, evaluate, or verify the accuracy or completeness of any information or the soundness of any judgments contained in
7、its standards and guideline publications. NEMA disclaims liability for any personal injury, property, or other damages of any nature whatsoever, whether special, indirect, consequential, or compensatory, directly or indirectly resulting from the publication, use of, application, or reliance on this
8、document. NEMA disclaims and makes no guaranty or warranty, expressed or implied, as to the accuracy or completeness of any information published herein, and disclaims and makes no warranty that the information in this document will fulfill any of your particular purposes or needs. NEMA does not und
9、ertake to guarantee the performance of any individual manufacturer or sellers products or services by virtue of this standard or guide. In publishing and making this document available, NEMA is not undertaking to render professional or other services for or on behalf of any person or entity, nor is
10、NEMA undertaking to perform any duty owed by any person or entity to someone else. Anyone using this document should rely on his or her own independent judgment or, as appropriate, seek the advice of a competent professional in determining the exercise of reasonable care in any given circumstances.
11、Information and other standards on the topic covered by this publication may be available from other sources, which the user may wish to consult for additional views or information not covered by this publication. NEMA has no power, nor does it undertake to police or enforce compliance with the cont
12、ents of this document. NEMA does not certify, test, or inspect products, designs, or installations for safety or health purposes. Any certification or other statement of compliance with any health or safetyrelated information in this document shall not be attributable to NEMA and is solely the respo
13、nsibility of the certifier or maker of the statement. ICS 2.4-2003 (R2012) Page iii Copyright 2012 by National Electrical Manufacturers Association FOREWORD This Standards Publication was prepared by a technical committee of the NEMA Industrial Automation Control Products and Systems Section. It was
14、 approved in accordance with the bylaws of NEMA and supersedes the indicated NEMA Standards Publication. This Standards Publication supersedes ICS 2.4-1989 (R2000). This Standards Publication provides practical information concerning ratings, construction, test, performance, and manufacture of indus
15、trial control equipment. These standards are used by the electrical industry to provide guidelines for the manufacture and proper application of reliable products and equipment and to promote the benefits of repetitive manufacturing and widespread product availability. NEMA Standards represent the r
16、esult of many years of research, investigation, and experience by the members of NEMA, its predecessors, its Sections and Committees. They have been developed through continuing consultation among manufacturers, users and national engineering societies and have resulted in improved serviceability of
17、 electrical products with economies to manufacturers and users. One of the primary purposes of this Standards Publication is to encourage the production of reliable control equipment which, in itself, functions in accordance with these accepted standards. Some portions of these standards, such as el
18、ectrical spacings and interrupting ratings, have a direct bearing on safety; almost all of the items in this publication, when applied properly, contribute to safety in one way or another. Properly constructed industrial control equipment is, however, only one factor in minimizing the hazards which
19、may be associated with the use of electricity. The reduction of hazard involves the joint efforts of the various equipment manufacturers, the system designer, the installer, and the user. Information is provided herein to assist users and others in the proper selection of control equipment. The indu
20、strial control manufacturer has limited or no control over the following factors which are vital to a safe installation: a. Environmental conditions b. System design c. Equipment selection and application d. Installation e. Operating practices f. Maintenance This publication is not intended to instr
21、uct the user of control equipment with regard to these factors except insofar as suitable equipment to meet needs can be recognized in this publication and some application guidance is given. This Standards Publication is necessarily confined to defining the construction requirements for industrial
22、control equipment and to providing recommendations for proper selection for use under normal or certain specific conditions. Since any piece of industrial control equipment can be installed, operated, and maintained in such a manner that hazardous conditions may result, conformance with this publica
23、tion 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 Electrical Code and properly maintained, the hazards to persons and property will be reduced. To continue to serve the be
24、st interests of users of Industrial Control and Systems equipment, the Industrial Automation Control Products and Systems Section is actively cooperating with other standardization organizations in the development of simple and more universal metrology practices. In this publication, the U.S. custom
25、ary units are gradually being supplemented by those of the modernized ICS 2.4-2003 (R2012) Page iv Copyright 2012 by National Electrical Manufacturers Association metric system known as the International Systems of Units (SI). This transition involves no changes in standard dimensions, tolerances, o
26、r performance specifications. NEMA Standards Publications are subject to periodic review. They are revised frequently to reflect user input and to meet changing conditions and technical progress. Proposed revisions to this Standards Publication should be submitted to: Senior Technical Director, Oper
27、ations National Electrical Manufacturers Association 1300 North 17th Street Rosslyn, Virginia 22209 This standards publication was developed by the Industrial Automation Control Products and Systems Section. Section Approval of the standard does not necessarily imply that all section members voted f
28、or its approval or participated in its development. At the time it was approved, the Section was composed of the following members: ABB Control, Inc. Wichita Falls, TX Alstom Power Conversion Pittsburgh, PA Automatic Switch Company Florham Park, NJ Balluff, Inc. Florence, KY Carlo Gavazzi, Inc. Buff
29、alo Grove, IL Control Concepts Corporation Beaver, PA Cooper Bussman St. Louis, MO Cummins, Inc. Minneapolis, MN CyberxLC RichmondVAEaton Corporation Milwaukee, WI Echelon Corporation San Jose, CA Electro Switch Corporation Weymouth, MA Emerson Process Management Austin, TX Entrelec, Inc. Irving, TX
30、 GE Industrial Systems Plainville, CT Hubbell Incorporated Madison, OH Joslyn Clark Controls, Inc. Lancaster, SC Lexington Switch such ratings are expressed via nameplates, catalogues, or technical literature. 1.2 MARKINGS 1.2.1 Nameplate Markings Both NEMA and IEC motor starters and contactors have
31、 nameplates (labels) that list ratings to help the user select and apply the devices. ICS 2.4-2003 (R2012) Page 2 Copyright 2012 by National Electrical Manufacturers Association 1.2.1.1 NEMA Nameplate Ratings NEMA Size: A standardized rating system of sizes for motor controllers. For each NEMA Size,
32、 there are specifically assigned horsepower, voltage, frequency, and current ratings as defined by the NEMA/ICS Standards. Horsepower and Voltage: The maximum rating (in horsepower) at various voltages corresponding to the values assigned for each NEMA Size. Continuous Current: The maximum current w
33、hich an enclosed starter or contactor may be expected to switch and carry continuously without exceeding the temperature rises permitted by the NEMA Standard. 1.2.1.2 IEC Nameplate Ratings HP and KW: The maximum rating for each mated operational voltage (Ue) and Utilization Category. The most common
34、 Kilowatt or 1HP ratings on a contactor or starter are for Utilization Category AC-3. Utilization Category (Examples: AC-1, AC-3): Describes the types of service for which the controller is rated. (See 2.1). Thermal Current (Ith): The maximum current which a contactor or a starter, each without its
35、enclosure, may be expected to carry continuously without exceeding the temperature rises allowed by the IEC Standard. This is not a load switching rating. Rated Operational Current (Ie): The maximum FLC at which a motor starter or contactor may be used for a given combination of voltage, frequency,
36、and utilization category (AC-1, AC-3, etc). A device may have more than one operational current. Rated Insulation Voltage (Ui): A design parameter sometimes shown on the nameplate that defines the insulation properties of the controller. It is not used for selection or application. Rated Operational
37、 Voltage (Ue): The voltage at which each stated horsepower or kilowatt rating applies. Standard Designation: The specific IEC Standard to which the product has been tested is required by IEC to be marked. 1.2.2 UL Markings Underwriters Laboratories, Inc. policy permits any complying motor control pr
38、oduct to be UL Listed, UL Recognized or UL Classified, and so marked. A product that is UL Listed carries the UL Listing Mark (UL in a circle) on its nameplate adjacent to the ratings to which the UL Listing Mark applies. Adjacent to the UL Listing Mark are the words “Listed Industrial Control Equip
39、ment“ or “Listed Ind. Cont. Eq.“ Listed industrial control equipment is suitable for installation with general use tools and for application at the ratings to which the Listing Mark is related. A UL Listed motor control product complies with the UL 508 Standard, and qualifies for installation under
40、specific provisions of the NEC. A motor control product that is UL Recognized may carry the UL Recognized Component Mark known as the “Backward UR“, the printed letters U and R, joined and reversed, as they would appear in a mirror. When used, according to UL, this mark must appear adjacent to the M
41、anufacturers identification and catalog number. UL Recognized equipment is not suitable for general use and must be combined with other items, under stated conditions of acceptability, into a product which, in turn, may be submitted to ICS 2.4-2003 (R2012) Page 3 Copyright 2012 by National Electrica
42、l Manufacturers Association UL, become UL Listed, and carry, the UL Listing Mark. The conditions of acceptability are published in the manufacturers “UL Component Recognition Report.“ A motor control product that is UL Classified carries the UL in a circle, the word Classified, and a notation that U
43、nderwriters Laboratories has evaluated the product with respect to compliance with a specific characteristic, standard, or part of a standard. ULs classification of a product to such a standard has no bearing on the product s ability to comply with UL 508, or to the NEC. Not every function or rating
44、 shown on the nameplate of a UL Listed, Recognized or Classified product is qualified for use under all Articles of the NEC or necessarily meets all UL Standards. For example, a motor controller with magnetic trip provisions, listed under UL 508 as a motor controller, may not necessarily meet the re
45、quirements for listing under UL 489. UL requires that where a contactor or starter carries a UL Listing Mark, only the ratings covered by that Listing Mark are to appear with the Mark on the nameplate. Other ratings, such as Kilowatt ratings, may be shown, but they must be appropriately segregated.
46、Under certain circumstances, UL allows the manufacturer to use a line as a means of separation between groupings of rating information to show that differentiation. Ratings adjacent to the UL Listing Mark relate to the Listing. Ratings shown on the opposite side of the line do not relate to the devi
47、ce Listing and do not qualify the device for general use in compliance with the NEC. 1.3 REFERENCES For ease of reference, those contactors, overload relays, and starters designed to meet NEMA and UL Standards, with the traditional features and conventions initially provided primarily for the North
48、American market, will be called traditional “NEMA” devices. Those contactors, overload relays, and starters designed to meet IEC Standards, with their associated traditional features and conventions, will be called traditional “IEC“ devices. Many IEC devices conform to NEMA and UL Standards and are
49、marked accordingly, differing only in conventions. Conversely, many NEMA devices conform to IEC Standards, and may be marked accordingly, differing only in conventions. 1.4 CONVENTIONS Practices followed by a majority of manufacturers selling in a given market have resulted in features and characteristics which are associated with either NEMA or IEC devices. This guide attempts to identify those resulting conventions as design philosophies. It also identifies differences in standards, where differences exist. Note: A convention, as used in this
