1、NEMA Standards PublicationNational Electrical Manufacturers AssociationNEMA LL 9-2011Dimming of T8Fluorescent LightingSystemsNEMA Standards Publication LL 9-2011 Dimming of T8 Fluorescent Lighting Systems Published by National Electrical Manufacturers Association 1300 North 17th Street, Suite 1752 R
2、osslyn, Virginia 22209 www.nema.org Copyright 2011 by the 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 Internati
3、onal and Pan American Copyright Conventions. 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 not necessarily mean that there is
4、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 voluntary consensus standards development pr
5、ocess. 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 does not write the document and it does
6、 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 any nature whatsoever, whether special
7、, 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, expressed or implied, as to the accuracy or completeness of any information published herein, and di
8、sclaims 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 or guide. In publishing and making
9、 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 his or her own independent judgment
10、 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 may wish to consult for additional
11、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 purposes. Any certification or other sta
12、tement of compliance with any health or safetyrelated information in this document shall not be attributable to NEMA and is solely the responsibility of the certifier or maker of the statement. LL 9-2011 Page i Copyright 2011 by the National Electrical Manufacturers Association. CONTENTS Foreword .
13、ii Section 1 GENERAL . 1 1.1 Scope . 1 1.2 References 1 Section 2 SYSTEM SPECIFICATIONS . 2 2.1 Lamp Characteristics . 2 2.2 Information for Dimming Ballast Design 2 LL 9-2011 Page ii Copyright 2011 by the National Electrical Manufacturers Association. Foreword The NEMA Lamp and Ballast Sections hav
14、e prepared this standards publication based on discussions with numerous manufacturers and end users following years of data gathering, testing, and analysis. In order for fluorescent dimming systems to provide maximum performance and safe operation, the system components should adhere to industry a
15、ccepted practices and meet appropriate National Electrical Manufacturers Association (NEMA), American National Standards Institute (ANSI), Underwriters Laboratories Inc. (UL), International Electrotechnical Commission (IEC), and Illuminating Engineering Society of North America (IESNA) standards and
16、 practices. The objective of this NEMA standard is to provide the reader with guidance for the design of high frequency fluorescent lamp dimming systems. The portion of this NEMA standard for dimming lamp currents at or above 60 mA became effective January 1, 2010. The portion of this NEMA standard
17、for dimming lamp currents below 60 mA becomes effective January 1, 2015. In the preparation of this standards publication, input of users and other interested parties has been sought and evaluated. Inquiries, comments, and proposed or recommended revisions should be submitted to the concerned NEMA p
18、roduct subdivision by contacting the: Vice President, Technical Services National Electrical Manufacturers Association 1300 North 17th Street, Suite 1752 Rosslyn, Virginia 22209 LL 9-2011 Page 1 Copyright 2011 by the National Electrical Manufacturers Association. Section 1 GENERAL 1.1 SCOPE This sta
19、ndards publication provides recommendations for dimmable T8 fluorescent lighting systems capable of being dimmed between approximately 100% and 10% of total light output. A T8 fluorescent lamp dimming system may include the following lamp types: 17 W, 2-foot; 25 W, 3-foot; 32 W, 4-foot; or 40 W, 5-f
20、oot lamps or other lamp types approved for use on the ballasts. 1.2 REFERENCES The following normative documents contain provisions, which through reference in this text constitute provisions of this standards publication. By reference herein, these publications are adopted, in whole or in part as i
21、ndicated, in this standards publication. ANSI/ANSLG C78.81-2010 Electric Lamps Double-Capped Fluorescent Lamps Dimensional and Electrical Characteristics ANSI C78.375-1997 Fluorescent Lamps Guide for Electrical Measurements ANSI C79.1-2002 Nomenclature for Glass Bulbs Intended for Use with Electric
22、Lamps ANSI/ANSLG C81.61-2009 Electrical Lamp Bases Specifications for Bases (Caps) for Electric Lamps ANSI C81.63-2007 Gauges for Electric Lamp Bases and Lampholders ANSI C82.3-2002 Reference Ballasts for Fluorescent Lamps ANSI C82.11-2002 High Frequency Fluorescent Lamp Ballasts Supplements ANSI C8
23、2.13-2002 Lamp Ballasts Definitions for Fluorescent Lamps and Ballasts IEEE 100-2000 The Authoritative Dictionary of IEEE Standards sTerms NEMA LSD 34-2006 Recommended Practices for T8 Rapid Start Fluorescent Lamp Dimming (17 W, 25 W, 32 W, and 40 W Lamps) LL 9-2011 Page 2 Copyright 2011 by the Nati
24、onal Electrical Manufacturers Association. Section 2 SYSTEM SPECIFICATIONS 2.1 LAMP CHARACTERISTICS Fluorescent lamp dimming systems are typically configured with adjacent lamp cathodes in the same ballast filament circuit. These cathodes may be connected in series or in parallel. Thus, a proper bal
25、ance of heating power between cathodes sharing the same circuit relies on well-balanced lamp cathode characteristics. Lamps in dimming applications should meet the following requirements. a) Lamps should comply with all relevant existing ANSI C78.81 standards requirements for non-dimming operation.
26、b) Hot cathode resistance, Rh, at 3.6 applied volts should be 12 2 ohms for each cathode. c) The ratio, Rh/Rc, of cathode hot resistance at 3.6 applied volts to cold resistance at 25C ambient temperature should be 4.75 0.50 for each cathode. 2.2 INFORMATION FOR DIMMING BALLAST DESIGN Dimming ballast
27、s should meet all the requirements of ANSI C82.11-2002 High Frequency Fluorescent Lamp Ballast under all operating conditions with the exception of the sections specifying ballast factor and input current harmonic distortion. Dimming ballasts should also meet the requirements of ANSI C82.11-2002 for
28、 ballast factor and input harmonic distortion during operation at full light output. For operation below rated current, the cathode requires supplemental ohmic heating by means of circulating current in the tungsten heater coil. The following are specifications for the voltage drop, EV, across each
29、cathode in a system of one or more lamps for a range of lamp current, ID, in dimmed operation (see also Figure 1). Maximum heating voltage (V): EVmax = 5.3 Minimum heating voltage (V): EVmin = 4.0 for 0.020 ID 0.050 (A) EVmin = 5 20*ID for 0.050 ID 0.100 (A) EVmin = 8.45 54.5*ID for 0.100 ID 0.155 (
30、A) EVmin = 0 for 0.155 ID (A) LL 9-2011 Page 3 Copyright 2011 by the National Electrical Manufacturers Association. 0 . 01 . 02 . 03 . 04 . 05 . 06 . 00 . 0 0 0 0 . 0 2 0 0 . 0 4 0 0 . 0 6 0 0 . 0 8 0 0 . 1 0 0 0 . 1 2 0 0 . 1 4 0 0 . 1 6 0L a m p C u r r e n t (A )ElectrodeVoltage(V)EV m i n EV m a xFigure 1 Electrode Voltage Limits for T8 Fluorescent Dimming Systems NATIONAL ELECTRICAL MANUFACTURERS ASSOCIATION 1300 NORTH 17TH STREET, SUITE 900 ROSSLYN. VA 22209www.NEMA.orgTO ORDER ADDITIONAL NEMA STANDARDS VISITWWW.GLOBAL.IHS.COM OR CALL 1-800-854-7179/1-303-397-79565612_0514TB
