1、NEMA Standards PublicationNational Electrical Manufacturers AssociationNEMA ICS 4-2015Application Guideline forTerminal BlocksNEMA Standards Publication ICS 4-2015 Application Guideline for Terminal Blocks Published by: National Electrical Manufacturers Association 1300 North 17th Street, Suite 900
2、Rosslyn, Virginia 22209 www.nema.org 2015 National Electrical Manufacturers Association. All rights, including translation into other languages, reserved under the Universal Copyright Convention, the Berne Convention for the Protection of Literary and Artistic Works, and the International and Pan Am
3、erican copyright conventions. 2015 National Electrical Manufacturers Association NOTICE AND DISCLAIMER The information in this publication was considered technically sound by the consensus of persons engaged in the development and approval of the document at the time it was developed. Consensus does
4、 not necessarily mean that there is unanimous agreement among every person participating in the development of this document. The National Electrical Manufacturers Association (NEMA) standards and guideline publications, of which the document contained herein is one, are developed through a voluntar
5、y 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 publication. While NEMA administers the process and establishes rules to promote fairness in the development of consensus, it doe
6、s 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 its standards and guideline publications. NEMA disclaims liability for any personal injury, property, or other damages of an
7、y nature whatsoever, whether special, indirect, consequential, or compensatory, directly or indirectly resulting from the publication, use of, application, or reliance on this document. NEMA disclaims and makes no guaranty or warranty, express or implied, as to the accuracy or completeness of any in
8、formation 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 undertake to guarantee the performance of any individual manufacturer or sellers products or services by virtue of this standard
9、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 NEMA undertaking to perform any duty owed by any person or entity to someone else. Anyone using this document should rely on h
10、is 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. Information and other standards on the topic covered by this publication may be available from other sources, which the user m
11、ay 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 contents of this document. NEMA does not certify, test, or inspect products, designs, or installations for safety or health purpos
12、es. Any certification or other statement of compliance with any health- or safety-related information in this document shall not be attributable to NEMA and is solely the responsibility of the certifier or maker of the statement. NEMA ICS 4-2015 Page i 2015 National Electrical Manufacturers Associat
13、ion Foreword This Applications Guideline was prepared by a technical committee of the NEMA Industrial Automation Control Products and Systems Section. It was approved in accordance with NEMA bylaws. It provides practical information concerning ratings, construction, test, performance, and manufactur
14、e of industrial control equipment. This publication is 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 Applications Gu
15、idelines represent the result of many years of research, investigation, and experience by the members of NEMA, its predecessors, and its sections and committees. They have been developed through continuing consultation among manufacturers, users, and national engineering societies and have resulted
16、in improved serviceability of electrical products with economies to manufacturers and users. One of the primary purposes of this Applications Guideline is to encourage the production of reliable control equipment that functions in accordance with accepted standards. Properly constructed industrial c
17、ontrol equipment is, however, only one factor in minimizing hazards that might be associated with the use of electricity. Hazard reduction involves the combined effort of the equipment manufacturers, the system designer, the installer, and the user. Information is provided herein to assist users and
18、 others in the proper selection of control equipment. The industrial 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 pra
19、ctices f) Maintenance This publication is not intended to instruct the control equipment user as regards these factors, except insofar as suitable equipment to meet particular needs might be recognized in this publication. Some application guidance is given. This Applications Guideline defines the c
20、onstruction requirements for industrial control equipment and provides recommendations on proper selection for use under normal or certain specific conditions. Since any piece of industrial control equipment can be installed, operated, and maintained in a manner that results in hazardous conditions,
21、 conformance with this publication does not in itself ensure a safe installation. When, however, equipment conforming to this Applications Guideline is properly selected, installed in accordance with the National Electrical Code (NEC), and properly maintained, hazards to persons and property will be
22、 reduced. To continue to serve the best interests of industrial control and systems equipment users, the Industrial Automation Control Products and Systems Section actively cooperates with other standardization organizations in the development of simple and more universal metrology practices. In thi
23、s publication, U.S. customary units are gradually being supplemented by those of the modernized metric system known as the International System of Units (SI). This transition requires no change in standard dimensions, tolerances, or performance specifications. NEMA Applications Guidelines are subjec
24、t to periodic review. They are revised frequently to reflect user input and to meet changing conditions and technical progress. Users should secure the latest editions. Proposed revisions to this Applications Guideline should be submitted to: NEMA ICS 4-2015 Page ii 2015 National Electrical Manufact
25、urers Association Vice President, Technical Services National Electrical Manufacturers Association 1300 North 17th Street, Suite 900 Rosslyn, VA 22209 Section approval of the Applications Guideline does not necessarily imply that all section members voted for its approval or participated in its deve
26、lopment. At the time this document was approved, the section was composed of the following members: ABB Inc. Low Voltage Products NOTETests in this standard are based on conductor ratings corresponding to 75C thermal insulation rating and 30C ambient. Results are also applicable to conductors of the
27、 same cross-section and any higher thermal insulation rating. b) The connecting capacity, including the type and number of conductors simultaneously connectable; c) The tightening torque values for the clamping screws; d) Rated insulation voltage; e) Service conditions, if different from those state
28、d in ICS 1, part 6; f) Marking “Cu” for terminal blocks used for copper conductors only; g) Marking “Al” for terminal blocks used for aluminum conductors only; h) Marking “Al-Cu” for terminal blocks suitable for the connection of aluminum or copper conductors; i) Service conditions, if different fro
29、m those of clause 6; j) The rated current (reference 4.3.6DV.1, ANSI/UL 60947-1); k) The tightening torque (reference 4.3.6DV.2, ANSI/UL 60947-1); l) Factory wiring only, when applicable (reference 4.3.6DV.3, ANSI/UL 60947-1); m) Special conductor preparation or use of prepared conductors (reference
30、 4.3.6DV.4, ANSI/UL 60947-1); n) Specific insulation types (insulation displacement/piercing). Reference 4.3.6DV.6, ANSI/UL 60947-1; o) Solid conductors only or stranded conductors only, as appropriate (reference 4.3.6DV.5, ANSI/UL 60947-1); p) Special conductor types (reference 4.3.6DV.4, ANSI/UL 6
31、0947-1); q) Instructions to clearly indicate any rearrangement or adjustment necessary to adapt to various sizes of wires; r) Instructions for proper installation of the wire where the wiring method is not obvious; s) A nominal strip length for a terminal block having screwless-type clamping units (
32、reference 4.3.6DV.7, ANSI/UL 60947-1); t) Rated operational voltage (reference 4.3.1DV, ANSI/UL 60947-1). NEMA ICS 4-2015 Page 10 2015 National Electrical Manufacturers Association 5.2 MARKING FOR PROTECTIVE CONDUCTOR TERMINAL BLOCKS A protective conductor terminal block shall be marked in a durable
33、 and legible manner with the following: a) the name of the manufacturer or a trade mark by which the manufacturer can be readily identified; b) a type reference permitting its identification in order to obtain relevant information from the manufacturer or his catalogue. A protective conductor termin
34、al block not complying with 7.1.4 ANSI/UL 60947-7-2, shall be marked with the symbol in Figure 6DV or with “G,” “GR,” “GND,” “Ground,” “Grounding,” or equivalent marking. 5.3.1 Additional Information The following information shall be stated by the manufacturer, if applicable, e.g., in the manufactu
35、rers data sheet or his catalog or on the packing unit: a) the rated cross-section; b) the rated connecting capacity. The manufacturer shall declare if the protective conductor terminal block rated equal to or above 8 AWG (10 mm2) is intended for PE function only. NOTE: No marking indicates suitabili
36、ty for use in PE function. c) service conditions, if different from those of clause 6. The information in subclause 5.2 of Annex C, item 1, ANSI/UL 60947-7-1 shall be stated by the manufacturer, except for rated operational voltage, rated current, rated insulation voltage, and rated impulse withstan
37、d voltage. 5.4 MARKING FOR FUSE TERMINAL BLOCKS A fuse terminal block shall be marked in a durable and legible manner with the following: a) the name of the manufacturer or a trademark by which the manufacturer can be readily identified; b) a type reference permitting its identification in order to
38、obtain relevant information from the manufacturer or his catalog; c) energy flow direction, if required to ensure protection against electric shock, according to 7.1.8 ANS/UL 60947-7-3, e.g., line-load marking or . 5.4.1 Additional Information The following information shall be stated by the manufac
39、turer, if applicable, e.g., in the manufacturers data sheet or catalog or on the packing unit: a) the rated cross-section; b) the rated connecting capacity, if different from ANSI/UL 60947-7-1, Table 2, including the number of conductors simultaneously connectable; c) the rated insulation voltage of
40、 the terminal block base and the fuse-carrier, if applicable; d) the working voltage or working voltage range, primarily determined by the fuse-link or by additional components, e.g., illuminated indicators; e) operating conditions, if different from clause 6; f) the size of the fuse-link. 5.5 MARKI
41、NG FOR TERMINAL BLOCKS WITH SHORT CIRCUIT CURRENT RATING GREATER THAN 10 kA Refer to ANSI/UL 1059, clause SA5, “Markings.” NEMA ICS 4-2015 Page 11 2015 National Electrical Manufacturers Association Section 6 CONSTRUCTION 6.1 TERMINAL ASSEMBLIES 6.1.1 Mechanical and Electrical Connection of Conductor
42、s The terminal assembly shall allow the conductors to be connected by means that ensure reliable mechanical and electrical connection. The construction of the terminal blocks shall not allow the conductors attached to the clamping units, the clamping units themselves, or the terminal assemblies to b
43、e displaced in a manner detrimental to the insulation. Likewise, under the above conditions, the construction shall not allow a reduction of clearance or creepage distance, or both. The terminal assembly shall be able to withstand the forces that can be applied through the connected conductors. Refe
44、r to ANSI/UL 60947-7-1, paragraph 7.1.1. For fuse terminal blocks, refer to ANSI/UL 60947-7-3, paragraph 7.1.1DV. 6.1.2 Terminal Assembly Material The main current-carrying parts of a terminal shall be of copper or copper alloy, aluminum or aluminum alloy, or steel. The steel shall be coated with an
45、 electrically conductive coating that will inhibit oxidation and corrosion. 6.1.3 Protective Coating of Terminal Assembly All combinations of terminal assembly and conductor materials shall have a protective coating, except the following combinations: a) aluminum or aluminum alloy terminal assemblie
46、s used only for the connection of aluminum conductors; b) copper or copper alloy terminal assemblies used only for the connection of copper conductors. Where protective coating is necessary, tin coating is acceptable for all combinations of terminal assemblies, including the clamping screws. 6.1.4 C
47、lamping of Conductors Terminal assemblies shall be so designed that contact pressure is not transmitted through insulating material. Refer to ANSI/UL 60947-7-1, paragraph 7.1.1. 6.2 MOUNTING MEANS Terminal blocks shall be provided with means that allow them to be securely attached to a rail, a mount
48、ing surface, or a printed circuit board (PCB). Refer to ANSI/UL 60947-7-1, paragraph 7.1.2. For protective conductor terminal blocks, refer to ANSI/UL 60947-7-2, paragraph 7.1.2DV.1. For fuse terminal blocks, refer to ANSI/UL 60947-7-3, paragraph 7.1.2DV. 6.3 IDENTIFICATION A terminal block shall be
49、 permitted to have provisions for identification marks or numbers for each clamping unit or terminal assembly to be related to the circuit of which it is to form a part. Refer to ANSI/UL 60947-7-1, paragraph 7.1.4. For protective conductor terminal blocks, refer to ANSI/UL 60947-7-2, paragraph 7.1.4DV.1. 6.4 CLEARANCE AND CREEPAGE DISTANCES Clearances and creepage distances shall be determined with the terminal blocks installed and connected according to the manufacturers instruction and for the most unfavorable combination of conductor cross-NEMA ICS 4-2015 Page 12 2015
