1、Designation:F252212Standard Test Method forDetermining the Protective Performance of a ShieldAttached on Live Line Tools or on Racking Rods for ElectricArc Hazards1This standard is issued under the fixed designation F2522;the number immediately following the designation indicates the year oforiginal
2、 adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method is used to determine the heat attenua-tion factor(HAF),th
3、e effective heat attenuation factor(EHAF),and the shields mechanical strength(SMS)of a shield attachedon live line tools or racking rods intended for protection ofworkers exposed to electric arcs.1.2 The materials used in this test method of workerprotection are in the form of a shield attached on l
4、ive line toolsor on the racking rods.1.3 The protective shield described in this test method shallbe transparent and shall be easily attached and removed fromlive line tools or from racking rods.1.4 The protective shield described in this test method has24-in.(0.61-m)diameter and can be used for mos
5、t applications,however for special cases,the shield can have different sizes tosuit the protective requirements of the application.1.5 This standard shall be used to measure and describe theproperties of materials,products,or assemblies in response toincident energies(thermal-convective,and radiant
6、and pressurewave)generated by an electric arc under controlled laboratoryconditions and does not purport to predict damage from light,resultant pressure impact other than the pressure and thermalaspects measured.1.6 The values stated in inch-pound units are to be regardedas standard.The values given
7、 in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.7 This standard shall not be used to describe or appraisethe fire hazard or fire risk of materials,products,or assembliesunder actual fire conditions.However,results of thi
8、s test maybe used as elements of a fire assessment,which takes intoaccount all of the factors,which are pertinent to an assessmentof the fire hazard of a particular end use.1.8 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility
9、of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.For specificprecautions,see Section 7.2.Referenced Documents2.1 ASTM Standards:2D4391 Terminology Relating to The Burning Behavior ofTextilesF195
10、9/F1959M Test Method for Determining theArc Ratingof Materials for Clothing3.Terminology3.1 Definitions:3.1.1 arc,nconductive path in air for the electric currentcaused by ionization of air between two electrodes.3.1.2 arc duration,ntime duration of the arc,s.3.1.3 arc energy,vi dt,nsum of the insta
11、ntaneous arcvoltage values multiplied by the instantaneous arc currentvalues multiplied by the incremental time values during thearc,J.3.1.4 arc gap,ndistance between the arc electrodes,cmin.3.1.5 arc voltage,nvoltage across the gap caused by thecurrent flowing through the resistance created by the
12、arc gap,V.See also Terminology D4391.3.1.6 asymmetrical arc current,nthe total arc currentproduced during closure;it includes a direct component and asymmetrical component,A.3.1.7 blowout,nthe extinguishing of the arc caused by amagnetic field.3.1.8 closure,npoint on supply current wave form wherear
13、c is initiated.1This test method is under the jurisdiction of ASTM Committee F18 onElectrical Protective Equipment for Workers and is the direct responsibility ofSubcommittee F18.35 on Tools&Equipment.Current edition approved Oct.1,2012.Published November 2012.Originallyapproved in 2005.Last previou
14、s edition approved in 2011 as F2522-05(2011).DOI:10.1520/F2522-12.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.
15、Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.9 effective heat attenuation(EHAF)/cone of protection(COP)factor,nthe percentage of the incident heat energythat is attenuated by the shield at the location of the worker.3.1.10 fragment
16、ation,nmolten metal fragments or otherfragments emitted from an electric arc.3.1.11 heat attenuation factor(HAF),nthe percentage ofthe incident heat energy that is blocked by the safety shieldmaterial.3.1.12 heat flux,nthe thermal intensity indicated by theamount of energy transmitted divided by area and timeW/m2calcm2s.3.1.13 i2t,nsum of the instantaneous arc current valuessquared multiplied by the incremental time values during thearc,A2/s.3.1.14 ignitability,n(ignitable,adj)in electric arcexp
