NFPA 780-2004 雷电保护系统的安装

Copyright National Fire Protection Association Provided by IHS under license with NFPANot for ResaleNo reproduction or networking permitted without license from IHS--,,,,,,--,,,,,,,---Copyright National Fire Protection Association Provided by IHS under license with NFPANot for ResaleNo reproduction or networking permitted without license from IHS--,,,,,,--,,,,,,,--- Copyright National Fire Protection Association Provided by IHS under license with NFPANot for ResaleNo reproduction or networking permitted without license from IHS--,,,,,,--,,,,,,,---Guyed ................................................................ 5.7Handling and processing grain, coal, and coke ................. 5.3Transient voltage surge suppressor TVSS .................MeasurementGround resistance, techniques .............................. Annex ERolling sphere model ................................................ 4.7.3Roofs780–50 INSTALLATION OF LIGHTNING PROTECTIElectric service ................................ 4.14.1.1, 4.18.1, A.4.18.1ElectrodesHeavy-duty stacks .......................................... 6.9.1, 6.9.2Selection criteria ......................IndexAssociation.in thereproducedClass II materialsDefinition .......................................... 3.3.18.2, A.3.3.18.2Heavy-duty stacks .................................................. 6.2.1HNAVSEA OP-5, Ammunition and Explosives Ashore, Volume 1,Sixth Revision, Chapter 6, Naval Sea Systems Command,Washington, DC, March 1995.Tobias, J. M., ed., The Basis of Conventional Lightning Protec-t3 Seek buildings, tents, and shelters in low areas avoidunprotected buildings.N.1.2.4 Other Reference.Moore, C. B., W. Rison, J. Mathis, and G. Aulich. “Lightning780–46 INSTALLATION OF LIGHTNING PAnnex M Guide for Personal Safety from LightningTable L.5d Determination of Lightning ConsequenceCoefficient C5780–45ANNEX MCopyright National Fire Protection Association Provided by IHS under licen3HAeTable L.4.3 Determination of Environmental Coefficient C1780–44 INSTALLATION OF LIGHTNING PROTECTION SYSTEMSCopyright National Fire Protection Association Provided by IHS under license with NFPANo780–43ANNEX LCopyright National Fire Protection Association Provided by IHS under license with NFPANot for ResaleNo reproduction or networking permitted without license from IHS--,,,,,,--,,,,,,,K.7.1 General. To ensure that the protection system used toprotect structures housing explosives is properly maintained,only the damage caused by a direct strike to the building orstructure to be protWhere an integral lightning protection system is used toprotect the structures covered by this annex, it is critical thatK.5 Bonding.780–41ANNEX KCopyright National Fire Protection Association Providelengths of insulating material to the ends of which the wirescan be attached. Such lengths of insulating material can con-can be utilized to aid in determining when to suspend theseoperations. There aG.1.1.1 Step Potential Reduction. Establishment of an electri-cally equipotential plane is desired to reduce step potentialG.2.2 Open Grandstands and Open Spectator Areas. Opengrandstands and open speThe total system ground resistance, R, can be calculatedfrom the ula780–38 INSTALLATION OF LIGHTNING PROTECTION SYSTEMSCopyright National Fire Protection Association Provided by IHS under licenserosion protection and has sized the components according totheir particular exposure to lightning damage. Many systemseveral thousand feet from the structure being protected. Theground resistance to bthe assumption that the current flow down the structure ismuch more symmetrical through the down conductors. ThisD.1.2 Visual Inspection. Visual inspections are made to ascer-tain the following780–36of down conductors to shorten the required bonding dis-tances are options to overcome these problems.The bonding techniques described in this standard call forbonding the gaps, such as BF, over which B.3.3 Conductors should be installed to offer the least im-pedance to the passage of stroke current between the strikesiderable size within a few feet of a conductor, there will be atendency for sparkwhen direct lightning strokes to the rims of floating-roof tankshave ignited flammable vapors within the open shells. Thesenum will provide, in most atmospheres, a lasting conductorfree of the effectsWhere installed, SPDs at branch panels or subpanelsshould have an Imaxrating of 20 kA 8/20 or greater per phase.discharge current to ground is affected by this impedance. Also, alower ground resistancamples of acceptable exceptions where SPDs may not be re-quired on each service entrance. The standard recognizes thatOutside zoneof protectionInside zoneof protection780–31ANNEX ACopyright National FAnnex A Explanatory Materialand t30 are times to the 90 percent and the 30 percent ampli-tude points on the leading edge of the wave. The dura-780–30 INSTALLATION OF LIGHTNING PROTECTION SYSTEMSCo8.5.4.2 Grounding Strip. An external grounding strip of cop-per, copper alloys, or stainless steel installed under the water-8.6.3 Metal Masses. Metal masses such as engines, generators,metallic tanks8.3.4 Nonmetallic Masts. A nonmetallic mast not within thezone of protection of a strike termination device shall be pro-8.4.4* Interconnecting Conductors.780–28 INSTALLATION OF LIGHTNING PROTECTION SCenter for50 ft heightCenter for75 ft heightCenter for100 ft heightCenter for25 ft height780–27PROTECTION FOR WATERCRAFTCopyright National Fire Protection Association Provided by IHS under license wit7.4.1.3 Metallic Tanks with Nonmetallic Roofs. Metallic tankswith wooden or other nonmetallic roofs shall not be self-8.2 Materials.780–26 INSTALLATION OF LIGHTNING PROTECTION SYSTEMSCopyright Nationa7.3.3.8* To prevent sideflashes, the minimum distance be-tween a mast or overhead ground wire and the structure to beAir terminal Air terminal780–25FLAMMABLE VAPORS, FLAMMABLE GASES, OR LIQUIDS THAT Cb.25780–24 INSTALLATION OF LIGHTNING PROTECTION SYSTEMSCopyright National Fire Protection Association Provided by IHS under license with NFPANot for ResaleNo reproduction or networking permitted wit6.10.2 Such metal stacks shall be grounded by means of atleast two ground terminals located on opposite sides of the7.2.5 Potential spark gaps between metallic conductors shallnot be allowed at points6.3.4 Air Terminal Mountings. 6.7 Reinforced Concrete Stacks.780–22 INSTALLATION OF LIGHTNING PROTECTION SYSTEMSCopyright National Fire Protection Association Provided by IHS under license with NFPANo5.3 Grain-, Coal-, and Coke-Handling and Processing Struc-tures. Provisions shall be made for the settling and rising ofA 2 m 8 ft maximum spacing of air terminals.B All equipment on upper 8 m 254.21.2.4 Structures More than 12 m 40 ft in Height. lightning conductor and the isolated metal body, and betweenthe isolated metal body and the grounded metal body is equal780–20 INSTALLATION OF LIG4.18.8* Earth Grounding Electrode. Resistance of the earthelectrode system used in the grounding of SPDs shall comply4.20.2* Roof-Level Potential Equalization. For structures ex-ceeding 18 m 60 ft i4.18.3 Surge Threat Levels. 4.18.6 Signal, Data, and Communications Surge Protection.ModeBe780–18 INSTALLATION OF LIGHTNING PROTECTION SYSTEMSCopyright National Fire Protection Association Provided by4.14.2.2 If the water pipe is not electrically continuous due tothe use of plastic pipe sections or other reasons, the noncon-4.16.3 Connections to Framework. Conductors shall be con-nected to areas o4.13.2.4* Multiple Ground Rods. Where multiple connectedground rods are used, the separation between any two ground4.13.6.2 The plate shall be buried not less than 460 mm 18 in.below grade.780–16 IN4.9.12 Down Conductors Entering Corrosive Soil. Down con-ductors entering corrosive soil shall be protected against cor-4.13.1.2 The design, size, depth, and number of ground ter-780–15PROTECTION FOR 4.9.5 Conductor Bends. No bend of a conductor shall anincluded angle of less than 90 degrees, nor shall it have a radius2 Most direct coursing of conductors3 Earth conditions780–14 INSTALLATI4.8.8.3 Required strike termination devices shall be installedon chimneys and vents, as shown in Figure 4.8.8.3, so that the780–13PROTECTION FOR ORDINARY STRUCTURESCopyright National Fire Protection AAA Air terminals within 0.6 m 2 ft of outermost projection of roof edgeFIGURE 4.8.5.2 Flat or Gently Sloping Roof with IrregularPerimeter.780–12 INSTALLATION OF LIGHTNING PROTECTION SYSTEMSCopyriCenter for 150 ft heightCenter for100 ft heightCenter for75 ft heightCenter for50 ft heightCenter for25 ft height25780–11PROTECTION FOR ORDINARY STRUCTURESCopyright National Fire Protection Associatio4.8 Strike Termination Devices on Roofs.780–10 INSTALLATION OF LIGHTNING PROTECTION SYSTEMSCopyright National Fire Protection Association Provided by IHS under license with NFPANot for ResaleNo reprod4.6.4 Ornaments.780–9PROTECTION FOR ORDINARY STRUCTURESCopyright National Fire Protection Association Provided by IHS under license with NFPANot for ResaleNo reproduction or networking permitted witho4.3 Corrosion Protection.780–8 INSTALLATION OF LIGHTNING PROTECTION SYSTEMSCopyright National Fire Protection Association Provided by IHS under license with NFPANot for ResaleNo reproduction or networTable 4.1.1.1B Minimum Class II Material Requirementsmmg/m2mmmmmm2780–7PROTECTION FOR ORDINARY STRUCTURESCopyright National Fire Protection Association Provided by IHS under license with NFPANot for3.3.25*SuppressedVoltageRatingSVR. A specific measuredlimiting voltage rating assigned to a transient voltage surgemode of protection of a transient voltage surge suppressorTVSS.SImmmmmmg/mmm2mmmm3.2.5 Shall. Indicates a mandatory requirement. 3.3.14 Heavy-Duty Stack. A smoke or vent stack with a fluethat has a cross-sectional area of the flue greater than 0.3 m2780–5DEFINITIONSCopyright NatioNFPA 7801.3 Listed, Labeled, or Approved Components. Where fit-tings, devices, or other components required by this standard780–4 INSTALLATION OF LIGHTNING PROTECTION SYSTEMSCopyright National Fire PrContentsChapter 1 Administration ............................... 780–4 6.5 Fasteners .......................................... 780–22780–3CONTENTSCopyright National Fire Protection Association ProvidTechnical Committee on Lightning ProtectionGerard M. BerIgnacio T. Cruz,Franco D’AlessandrDennis P. Dillon,FL [IM]Rep. LightningDouglas J. Franklin,Inc., MN [M]John R. Fredlund,DC [E]Thomas R. HarIL [preparedMaybysupersedes2004.standardsandbinedInstitute1947the1968,designationPrbytent.clarifystreamermorenotintendedinstallationsuchlightningwithadministrativetions,”sequencemultiplezationandcommonlyrADDITIONAL NOTICES AND DISCLAIMERSUpdating of NFPA DocumentsUsers of NFPA codes, standards, recommended practices, and guides should be aware thatthese documents may be superseded at any time by the iIMPORTANT NOTICES AND DISCLAIMERS CONCERNING NFPA DOCUMENTSNOTICE AND DISCLAIMER OF LIABILITY CONCERNING THE USE OF NFPA DOCUMENTSNFPA codes, standards, recommended practices, and guides, of which theNFPA 780 Standard for the Installation of Lightning Protection Systems 2004 Edition NFPA, 1 Batterymarch Park, Quincy, MA 02169-7471 An International Codes and Standards Organization Copyright Nationa