1、IEEE Std C37.24-2003(Revision of IEEE Std C37.24-1986)IEEE StandardsC37.24TMIEEE Guide for Evaluating the Effect of Solar Radiation on Outdoor Metal-Enclosed SwitchgearPublished by The Institute of Electrical and Electronics Engineers, Inc.3 Park Avenue, New York, NY 10016-5997, USA26 February 2004I
2、EEE Power Engineering SocietySponsored by theSwitchgear CommitteeIEEE StandardsPrint: SH95149PDF: SS95149Authorized licensed use limited to: IHS Stephanie Dejesus. Downloaded on October 22, 2008 at 14:19 from IEEE Xplore. Restrictions apply.Recognized as anAmerican National Standard (ANSI)The Instit
3、ute of Electrical and Electronics Engineers, Inc.3 Park Avenue, New York, NY 10016-5997, USACopyright 2004 by the Institute of Electrical and Electronics Engineers, Inc.All rights reserved. Published 26 February 2004. Printed in the United States of America.IEEE is a registered trademark in the U.S.
4、 Patent +1 978 750 8400. Permission to photocopy portions of any individual standard for educationalclassroom use can also be obtained through the Copyright Clearance Center.Note: Attention is called to the possibility that implementation of this standard may require use of subject mat-ter covered b
5、y patent rights. By publication of this standard, no position is taken with respect to the existence orvalidity of any patent rights in connection therewith. The IEEE shall not be responsible for identifying patentsfor which a license may be required by an IEEE standard or for conducting inquiries i
6、nto the legal validity orscope of those patents that are brought to its attention.Authorized licensed use limited to: IHS Stephanie Dejesus. Downloaded on October 22, 2008 at 14:19 from IEEE Xplore. Restrictions apply.Copyright 2004 IEEE. All rights reserved. iiiIntroduction(This introduction is not
7、 part of IEEE Std C37.24-2003, IEEE Guide for Evaluating the Effect of Solar Radiation on Out-door Metal-Enclosed Switchgear.)This guide is an outgrowth of a technical paper presented at the AIEE winter general meeting in New York,NY, January 1822, 1954. In October 1955, the paper was issued by the
8、AIEE Standards Committee as Pub-lication 955. In 1962, 3000 A ratings were added and the temperature data from the National Oceanic andAtmospheric Administration were updated. Subsequently, it was revised and published as an IEEE guide in1971. A new section was added in the 1986 guide discussing col
9、or and finish of the metal-enclosed switch-gear and their impact on temperature due to solar radiation.This guide is a revision of IEEE Std C37.24-1986. Standards references have been updated and the latesttemperature data (for 19611990) for the US and Canada has been included. This revision also in
10、cludes met-rification of English units and the additional bibliographical entries to cover broad geographic locations.ParticipantsThis guide was prepared by a working group operating under the Switchgear Assemblies Subcommittee ofthe IEEE Switchgear Committee. At the time this guide was completed, t
11、he working group had the follow-ing membership: S. S. Gohil, ChairThe Switchgear Assemblies Subcommittee of the IEEE Switchgear Committee, which reviewed andapproved this guide, had the following membership:D. J. Lemmerman, ChairD. J. EdwardsA. F. MorganP. J. NotarianG. R. NourseE. ODonnellT. W. Ols
12、enS. H. TelanderM. WactorC. J. BallT. A. BurseE. R. ByronJ. J. DravisD. J. EdwardsS. S. GohilR. K. IyerJ. M. JerabekW. E. LaubachW. C. McKayA. F. MorganP. J. NotarianG. R. NourseT. W. OlsenG. O. PerkinsE. A. PetersR. J. PuckettG. SakatsS. H. TelanderM. WactorAuthorized licensed use limited to: IHS S
13、tephanie Dejesus. Downloaded on October 22, 2008 at 14:19 from IEEE Xplore. Restrictions apply.iv Copyright 2004 IEEE. All rights reserved.This guide was processed and approved for submittal to ANSI by the Accredited Standards Committee onPower Switchgear C37. Committee approval of the guide does no
14、t necessarily imply that all committeemembers voted for its approval. At the time of its approval, the C37 Committee had the following members:T. W. Olsen, Temporary Chair A.K. McCabe, Executive Vice Chair, HV StandardsJ. Scott, Executive Vice Chair, LV StandardsD.L. Swindler, Executive Vice Chair,
15、IEC ActivitiesJ. Collins, SecretaryOrganization Represented Name of RepresentativeElectric Light and Power Group D. E. GaliciaJoseph L. KoepfingerG. J. MartuscelloY. MusaE. WorlandInstitute of Electrical and Electronics Engineers, Inc. A. DixonJ. M. JerabekD. SigmonD. J. Lemmerman (Alt.)T. E. Royste
16、rR. W. Long (Alt.)J. G. Wood (Alt.) National Electrical Manufacturers Association . G. JonesW. LongT. W. OlsenG. SakatsD. StoneInternational Electrical Testing Association A. PetersenNational Electrical Contractors Association D. HarwoodTesting Laboratory Group . P. J. NotarianE. RoseenTennessee Val
17、ley Authority. J. NelsonUS Dept. of Agriculture. H. L. BowlesUS Dept. of the ArmyOffice of the Chief of Engineers J. A. GibsonUS Dept. of the NavyNaval Construction Battalion Center D. L. MillsTechnical Liaison. W. E. LaubackC. WagnerAuthorized licensed use limited to: IHS Stephanie Dejesus. Downloa
18、ded on October 22, 2008 at 14:19 from IEEE Xplore. Restrictions apply.Copyright 2004 IEEE. All rights reserved. vThe following members of the balloting committee voted on this standard. Balloters may have voted forapproval, disapproval, or abstention. When the IEEE-SA Standards Board approved this s
19、tandard on 12 June 2003, it had the followingmembership:Don Wright, ChairHoward M. Frazier, Vice ChairJudith Gorman, Secretary*Member EmeritusAlso included are the following nonvoting IEEE-SA Standards Board liaisons:Alan Cookson, NIST RepresentativeSatish K. Aggarwal, NRC RepresentativeNoelle D. Hu
20、menickIEEE Standards Project EditorChris AmbroseStan J. ArnotAnne BosmaDave BurnsTed BurseTommy CooperGuru Dutt DhingraAlexander DixonDenis DufournetDoug EdwardsMarcel FortinDavid GilmerS. (Dave) GohilRandall GrovesErik GuillotBob HughesWilliam HurstRichard JacksonJerry JerabekStephen R. LambertThom
21、as LaroseWard LaubachR. W. LongGregory LuriJohn MartinKenneth McclenahanJohn MerandoGary MichelDaleep MohlaGeorges MontilletAnne MorganFrank MuenchPaul NotarianGeorge NourseEdward ODonnellT. W. OlsenMiklos OroszEdward PetersJames RuggieriGerald SakatsJordan ShikoskiShaun SlatteryH. Melvin SmithDavid
22、 StoneAlan StormsStanton TelanderShanmugan ThamilarasanGerald VaughnCharles WagnerJames WilsonH. Stephen BergerJoe BruderBob DavisRichard DeBlasioJulian Forster*Toshio FukudaArnold M. GreenspanRaymond HapemanDonald M. HeirmanLaura HitchcockRichard H. HulettAnant JainLowell G. JohnsonJoseph L. Koepfi
23、nger*Tom McGeanSteve MillsDaleep C. MohlaWilliam J. MoylanPaul NikolichGary RobinsonMalcolm V. ThadenGeoffrey O. ThompsonDoug ToppingHoward L. WolfmanAuthorized licensed use limited to: IHS Stephanie Dejesus. Downloaded on October 22, 2008 at 14:19 from IEEE Xplore. Restrictions apply.vi Copyright 2
24、004 IEEE. All rights reserved.Contents1. Overview 11.1 Introduction 11.2 Scope 11.3 Purpose. 22. References 23. Operating limitations . 24. External influences on internal operating temperatures 34.1 Ambient temperatures 34.2 Solar radiation 44.3 Wind influence. 55. Ventilation and condensation cont
25、rol 56. Enclosure color and finish considerations . 57. Current-carrying capabilities of switchgear. 67.1 Metal-clad switchgear 67.2 Metal-enclosed low-voltage power circuit breaker switchgear . 77.3 Metal-enclosed interrupter switchgear. 77.4 Control switchboards . 77.5 Metal-enclosed bus 88. Sugge
26、sted modifications of standard designs 89. Conclusion . 8Annex A (informative) Figures 9Annex B (informative) Tables . 11Annex C (informative) Conversion tables . 27Annex D (informative) Bibliography 30Authorized licensed use limited to: IHS Stephanie Dejesus. Downloaded on October 22, 2008 at 14:19
27、 from IEEE Xplore. Restrictions apply.Copyright 2004 IEEE. All rights reserved. 1IEEE Guide for Evaluating the Effect of Solar Radiation on Outdoor Metal-Enclosed Switchgear1. Overview1.1 Introduction Outdoor metal-enclosed low-voltage power circuit breaker switchgear, outdoor metal-clad switchgear,
28、 andoutdoor metal-enclosed interrupter switchgear have reached a position of widespread applicationcomparable to that of indoor switchgear. Outdoor switchgear has had a satisfactory operating record formany years in cold, temperate, and hot climates that has contributed to this increased usage. Howe
29、ver, thereare conditions affecting the application of outdoor switchgear that are different from those for indoorswitchgear and warrant special consideration.Realizing this situation, a study for metal-enclosed switchgear was undertaken by the SwitchgearAssemblies Subcommittee. It was soon establish
30、ed that temperature data were not available on fully loadedunits in the field. Outdoor laboratory and field testing was then tried, and it became evident that, due touncontrollable conditions, accurate and complete data suitable for establishing the current-carryingcapability of outdoor metal-enclos
31、ed switchgear could not be obtained. Metal-enclosed switchgear was thentested indoors with outdoor conditions simulated. While valuable data were accumulated, no reliablerelationship between results obtained indoors and conditions existing outdoors was found. However, basedon these investigations, s
32、ufficient data were accumulated for the preparation of a guide for application ofoutdoor metal-enclosed switchgear in various climates.1.2 ScopeThe general information in this guide is intended to assist in evaluating the effect of solar radiation onoutdoor metal-enclosed switchgear and is applicabl
33、e to outdoor metal-enclosed power switchgear, controlswitchboards, and metal-enclosed bus. Specific data are given in current-temperature relationship andtabulation form for outdoor metal-enclosed low-voltage power circuit breaker switchgear, outdoor metal-clad switchgear, and outdoor metal-enclosed
34、 interrupter switchgear.Authorized licensed use limited to: IHS Stephanie Dejesus. Downloaded on October 22, 2008 at 14:19 from IEEE Xplore. Restrictions apply.IEEEStd C37.24-2003 IEEE GUIDE FOR EVALUATING THE EFFECT OF2 Copyright 2004 IEEE. All rights reserved.1.3 PurposeSwitchgear will perform sat
35、isfactorily and have a reasonable life when operated within the temperaturelimits established in IEEE Std C37.20.1-2002, IEEE Std C37.20.2-1999, IEEE Std C37.20.3-2001,IEEE Std C37.21-1985, and IEEE Std C37.23-1987. These standards specify the temperature rise limitsabove a standard (maximum) ambien
36、t temperature of 40 C. This is satisfactory for indoor applicationswhere the temperature rise is due entirely to heat release (internal losses). In outdoor applications, thelimiting temperatures result from the net effect of internal losses and external influences, principally the sun,wind, and loca
37、l ambient temperatures. All of these must be considered in determining the current-carryingcapacity of outdoor metal-enclosed switchgear.The magnitude of these factors will vary geographically and from season to season. The time relationship ofmaximum circuit loads with respect to maximum ambient te
38、mperature is important. It is not practical todesign switchgear on the basis that all adverse factors reach their maxima coincident with maximum loads.If this does not occur, full current ratings may be realized. Recommendations will be made to point out thecumulative effect of these various influen
39、ces.2. ReferencesThis guide shall be used in conjunction with the following publications. When these standards aresuperseded by an approved revision, the revision shall apply.IEEE Std C37.20.1-2002, IEEE Standard for Metal-Enclosed Low-Voltage Power Circuit BreakerSwitchgear.1, 2IEEE Std C37.20.2-19
40、99, IEEE Standard for Metal-Clad Switchgear.IEEE Std C37.20.3-2001, IEEE Standard for Metal-Enclosed Interrupter Switchgear. IEEE Std C37.21-1985, IEEE Standard for Control Switchboards. IEEE Std C37.23-1987, IEEE Guide for Metal-Enclosed Bus and Calculating Losses in Isolated-Phase Bus. IEEE/ASTM S
41、I 10-2002, American National Standard for Use of the International Systems of Units (SI):The Modern Metric System.3. Operating limitationsTemperature limitations for metal-enclosed switchgear are established to ensure a satisfactory life span ofthe insulation. Operation at higher temperatures than p
42、ermitted by the appropriate standard will result inshortened life, but if the temperature of the insulation goes above normal for only a few hours during just afew days of the year, the effect on total life is hardly measurable. This is very different from theestablishment of higher short-duration r
43、atings that might be repetitive on a day-to-day basis. The hazard ofimmediate breakdown is not increased unless extreme temperatures are reached.To exclude wind-blown dust and dirt, outdoor metal-enclosed switchgear is usually designed with morerestricted ventilation than indoor switchgear. Because
44、of this design difference, outdoor switchgear has a1The IEEE standards or products referred to in Clause 2 are trademarks of the Institute of Electrical and Electronics Engineers, Incorpo-rated.2IEEE publications are available from the Institute of Electrical and Electronics Engineers, 445 Hoes Lane
45、, P.O. Box 1331, Piscataway, NJ 08855-1331, USA (http:/standards.ieee.org/).Authorized licensed use limited to: IHS Stephanie Dejesus. Downloaded on October 22, 2008 at 14:19 from IEEE Xplore. Restrictions apply.IEEESOLAR RADIATION ON OUTDOOR METAL-ENCLOSED SWITCHGEAR Std C37.24-2003Copyright 2004 I
46、EEE. All rights reserved. 3somewhat increased internal temperature even when there is an equivalent number of circuit breakers andbuses. These conditions have been recognized in designs. With this restricted ventilation, the effect of solarradiation on an enclosure will cause the air immediately und
47、er the roof to be relatively warm. Electrical partslocated near the roof will operate in air considerably warmer than that surrounding equipment in the centeror lower portion of the switchgear units. Some types of cable insulation may not be rated for the higher airtemperature found immediately unde
48、r the roof. If cables are located in the upper part of housings, insulationwith appropriate thermal characteristics should be selected. IEEE Std C37.20.1-2002, IEEE Std C37.20.2-1999, and IEEE Std C37.20.3-2001 state, in effect, that the temperature of the air surrounding insulatedcables within any
49、compartment shall not exceed 65 C when the assembly is in an ambient air temperature of40 C. This temperature is based on the use of 90 C insulated power cables. Use of lower temperature ratedcables requires special consideration. In many cases the effect of solar radiation alone will raise the insidetemperature above that permitted by the appropriate standard. The insulation and size of conductors in thislocation should be carefully considered by both manufacturers and users.End units, particularly those exposed to the sun during periods of heavy load, should
