1、NEMA Standards PublicationNational Electrical Manufacturers AssociationANSI C78.79-2014Nomenclature for Envelope Shapes Intended for Use with Electric LampsC78.79-2014 Page i 2014 National Electrical Manufacturers Association American National Standard Approved: 06/19/2014 Secretariat: National Elec
2、trical Manufacturers Association for Electric Lamps Nomenclature for Envelope Shapes Intended for Use with Electric Lamps ANSI C78.79-2014 An American National Standard implies a consensus of those substantially concerned with its scope and provisions. It is intended as a guide to aid the manufactur
3、er, the consumer, and the general public. The existence of an American National Standard does not in any respect preclude anyone, whether he has approved the standard or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the standards. Users
4、 are cautioned to obtain the latest editions. The American National Standards Institute does not develop standards and will in no circumstances give an interpretation of any American National Standard. Moreover, no person shall have the right or authority to issue an interpretation of an American Na
5、tional Standard in the name of the American National Standards Institute. CAUTION NOTICE: This American National Standard may be revised or withdrawn at any time. The procedures of the American National Standards Institute require that action be taken periodically to reaffirm, revise, or withdraw th
6、is standard. Purchasers of American National Standards may receive current information on all standards by calling or writing the American National Standards Institute. C78.79-2014 Page ii 2014 National Electrical Manufacturers Association American National Standard Approval of an American National
7、Standard requires verification by ANSI that the requirements for due process, consensus, and other criteria for approval have been met by the standards developer. An American National Standard implies a consensus of those substantially concerned with its scope and provisions. Consensus is establishe
8、d when, in the judgment of the ANSI Board of Standards Review, substantial agreement has been reached by directly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be consid
9、ered, and that a concerted effort be made toward their resolution. The existence of an American National Standard does not in any respect preclude anyone, whether s/he has approved the standard or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conform
10、ing to the standards. It is intended as a guide to aid the manufacturer, the consumer, and the general public. The American National Standards Institute does not develop standards and will in no circumstances give an interpretation of any American National Standard. Moreover, no person shall have th
11、e right or authority to issue an interpretation of an American National Standard in the name of the American National Standards Institute. Requests for interpretations should be addressed to the Committee Secretary referred to in the foreword. CAUTION NOTICE: This American National Standard may be r
12、evised or withdrawn at any time. The procedures of the American National Standards Institute require that action be taken periodically to reaffirm, revise, or withdraw this standard. Purchasers of American National Standards may receive current information on all standards by calling or writing the
13、American National Standards Institute. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without prior written permission of the publisher. Printed in the United States of America. C78.79-2014 Page iii 2014 National Electrical Manufacturers As
14、sociation Foreword (This Foreword is not part of ANSI C78.79.-2014.) This is a revised and re-designated standard recently updated by American National Standards Committee C78 on Electric Lamps. Suggestions for improvement of this standard should be submitted to the Senior Technical Director, Operat
15、ions National Electrical Manufacturers Association 1300 North 17th Street, Suite 900 Rosslyn, VA 22209 This standard was processed and approved by Accredited Standards Committee on Electric Lamps, ASC C78. Committee approval of the standard does not necessarily imply that all committee members voted
16、 for that approval. The purpose of the revision and re-designation of this horizontal standard is to include solid state light sources that are functional applications of traditional lamps (incandescent, fluorescent and high intensity discharge lamps). This horizontal standard was first developed in
17、 the 1940s by the Accredited Standards Committee (ASC) C79 under this secretariat. ASC C79 has been disbanded and consolidated into the work program of ASC C78. The following represents some of the select changes incorporated into this proposed revision/re-designation: Change designation from ASC C7
18、9 to ASC C78 A Patent Disclaimer statement The statement “glass bulb” replaced with “envelope shapes” for the electric lamp Inclusion of relevant normative standards Inclusion of envelope shapes germane to solid state lighting. As an example, the “MRX” (multifaceted reflector, extended). C78.79-2014
19、 Page iv 2014 National Electrical Manufacturers Association TABLE OF CONTENTS Foreword . iiii 1 Scope . 1 2 Definitions 2 2.1 Bulb . 2 2.2 Approximate Reference Line or CD Line 2 2.3 Base Line or Base Circle 2 2.4 Base Line Length 2 3 Designations 3 3.1 General (Other than Rectangular) . 3 3.1.1 Fir
20、st Letter Symbol . 3 3.1.2 First Number Symbol . 3 3.1.3 Second Letter Symbol 3 3.1.4 Second Number Symbol 3 3.1.5 Fluorescent And PAR 8 4 Units . 8 4.1 Customary Units . 8 4.2 SI (Metric) Units 9 4.2.1 General 9 4.2.2 Fluorescent Bulbs 9 4.2.3 Round PAR 9 4.2.4 Rectangular Bulbs . 9 4.2.5 Solid Sta
21、te Envelopes 9 5 Examples of Designations 10 5.1 Customary Units . 10 5.2 SI (Metric) Units 11 6 Bulb Shape Classification 11 6.1 Basic Shapes 11 6.2 Modifiers . 14 7 Identification of Bulbs for Use in Lamps . 15 7.1 Lamp Description in Customary Units . 15 7.2 Lamp Description in Metric Units 15 An
22、nexes Annex A (Informative) Decimal Equivalents and Metric Conversions of Existing Bulbs A-3 Annex B (Informative) Related Standards A-7 C78.79-2014 Page 1 2014 National Electrical Manufacturers Association American National Standard Nomenclature for Envelope Shapes Intended for Use with Electric La
23、mps 1 Scope This standard describes a system of nomenclature that provides designations for envelope shapes used for all electric lamps. This system is shown in customary (inch-based) units and SI (metric-based) units. These envelope shapes are intended to be used with ANSI standardized base and hol
24、der systems. These general shapes are not associated with specific base and holder systems; they may be used with one or more of these systems. The nomenclature system is intended for application with LED lamps and glass bulbs that originate both as parts and as stock. As a part, a bulb is assembled
25、 directly into finished lamps without major alterations. As stock, a bulb may be re-worked or altered during lamp assembly, while maintaining its basic identifying characteristics. 1.1 Important Patent Disclaimer It is possible that some of the elements of this document may be the subject of patent
26、rights. When this document was approved for publication, the National Electrical Manufactures Association did not know of any patent applications, patents pending, or existing patents. NEMA shall not be held responsible for identifying any or all such patent rights. 1.2 Normative References The foll
27、owing standards contain provisions, which through reference in this text constitute provisions of this American National Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this American National Standard
28、are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. The following normative reference standards are the other ANSI lamp specific dimensional and performance standards that should be used with this standard. ANSI C81.61-2009 Bases (Caps
29、) for Electric Lamps ANSI C81.62-2009 Electric Lampholders C78.79-2014 Page 2 2014 National Electrical Manufacturers Association ANSI C81.63-2009 Gauges for Electric Lamp Bases and Lampholders ANSI_IEC C81.64-2005 Guidelines and General Information for Electric Lamp Bases, Lampholders and Gauges 2 D
30、efinitions 2.1 Bulb The outer envelope of glass or other material enclosing the essential components of an electric lamp. The material may be transparent, translucent, opaque, or of a surface emitting material. 2.2 Approximate Reference Line or CD Line A construction line transverse to the axis thro
31、ugh the neck of the bulb. It defines the approximate position at which the rim of a base, such as an Edison screw base, would meet the neck of a bulb. The sole purpose of the approximate reference line is to aid the establishment of technical definitions of bulb shapes. This line appears in figure 1
32、 as a CD line. No such line exists for pressed glass bulbs. 2.3 Base Line or Base Circle A diameter on the end portion of a bulb at the approximate point where the base seats. The concept of a base line or base circle is applicable only to double-ended tubular lamp bulbs. 2.4 Base Line Length The di
33、stance between the two base lines. C78.79-2014 Page 3 2014 National Electrical Manufacturers Association 3 Designations 3.1 General (Other than Rectangular) Bulbs (glass and other materials), also known as envelope shapes, shall be described by a designation consisting of the following sequence of l
34、etter and number symbols, without spaces in between, as follows: a) A first letter symbol comprising up to three letters describing the bulb shape. The letter or letters of this symbol may, in some cases, be a basic shape, letter symbol only, and in other cases, it may be a combination of a basic sh
35、ape symbol and a modifier or modifiers. Basic shapes are defined in clause 6.1 and modifiers are defined in clause 6.2. b) A first number symbol indicating the major diameter (nominal) of the bulb c) A second letter symbol consisting of one or two arbitrary letters d) A second number symbol using ar
36、bitrary numbers 3.1.1 First Letter Symbol The first letter symbol shall identify the shape classification to which the bulb belongs. The letter symbols that have thus far been established are described in Clause 6.1 and illustrated in Figure 1. If additional symbols are adopted, the letters I, O, Q,
37、 and U shall not be used. 3.1.2 First Number Symbol The first number symbol shall indicate one of the following: a) The nominal major diameter of that part of the bulb above the CD line b) The nominal major diameter of a tubular bulb c) The maximum diameter of a round PAR bulb 3.1.3 Second Letter Sy
38、mbol The second letter symbol shall serve to distinguish between bulbs having the same shape classification and major diameter but differing in other features above the CD line. The letters of the second letter designation shall be assigned in alphabetical order beginning with A. The letters, I, O,
39、Q, and U shall not be used. If more than 22 variations are encountered, a second series beginning ZA, ZB, etc., shall be used. The third series, if needed, shall be YA, YB, etc. 3.1.4 Second Number Symbol The second number symbol shall serve to distinguish between bulbs alike in all respects above t
40、he CD line but differing below the CD line. C78.79-2014 Page 4 2014 National Electrical Manufacturers Association Figure 1 Basic Bulb Shapes C78.79-2014 Page 5 2014 National Electrical Manufacturers Association Figure 1 (continued) C78.79-2014 Page 6 2014 National Electrical Manufacturers Associatio
41、n Figure 1 (continued) C78.79-2014 Page 7 2014 National Electrical Manufacturers Association Figure 1 (continued) MRX C78.79-2014 Page 8 2014 National Electrical Manufacturers Association 3.1.5 Fluorescent and PAR Several variations exist in designating single-based fluorescent bulbs and PAR-type en
42、velope shapes. Most manufacturers use the first letter and first number symbols designated in this standard, but vary in assignments of second letter and second number symbols. 4 Units It is an objective to harmonize envelope shape designations internationally. Therefore, either of two types of desi
43、gnations, customary or metric, or dual designation showing both units may be used. The relationship of customary, decimal and metric nomenclature for existing bulbs is shown in Annex A. Committee C78 shall develop any additional conversions that may be necessary. 4.1 Customary Units The nominal valu
44、e of a bulbs major diameter shall be the basis of the bulb size unit. The unit shall be expressed in eighths of an inch, with fractions added when necessary. A tubular shaped bulb, for example, 1-1/4 inches (10/8ths) in diameter is called a T10 bulb. Fractional units are added with regard to the fol
45、lowing size ranges. Bulb Size Fractional Units 3/4” Half of an eighth of an inch, 1/16th. An example of determining bulb size with fractional units in the ” to ” diameter range is as follows, for a nominal bulb diameter of 0.335 inch. = 0.250 + 0.085 = 0.250 + 0.062 + 0.023 0.335 = 2/8 + 2/32 + 0.02
46、3/0.031 = 2/8 + 3/32 (rounded upward) = 2 units + 3 fractional units (As a T2-3/4 bulb, for example) The optional and interchangeable use of decimal equivalents, instead of fractions, is allowed for bulbs with fractional size designations. Any decimal shall be rounded to one significant place. C78.7
47、9-2014 Page 9 2014 National Electrical Manufacturers Association For the same bulb size as used in the preceding note, 0.335 inch, the decimal size would be calculated as follows. = 0.250 + 0.085 = 2/8 + 85/125 0.335 = 2 units + 0.68 decimal units = 2.7 (rounded upward) (As a T2.7 bulb, for example)
48、 4.2 SI (Metric) Units 4.2.1 General In metric designations the first number symbol shall consist of two numbers expressed in millimeters (to the nearest whole number) and separated by a diagonal line. Unless specified in subsequent clauses, the number to the left of the diagonal shall indicate the
49、major bulb diameter above the CD line; the number to the right of the diagonal shall indicate the diameter of the bulb neck at the CD line. 4.2.2 Fluorescent Bulbs For fluorescent bulbs the two-number symbol described in 4.2.1 shall be used. The number to the left of the diagonal shall designate the bulb diameter in millimeters (to the nearest whole number); the number to the right of the diagonal shall designate the base line length to the closest millimeter. 4.2.3 Round PAR Only one number shall be used to designate round PAR-typ
