ASTM E1725-1995(2001)e1 Standard Test Methods for Fire Tests of Fire-Resistive Barrier Systems for Electrical System Components《电气系统元件耐火阻挡层系统耐火试验的标准试验方法》.pdf

1、Designation: E 1725 95 (Reapproved 2001)e1An American National StandardStandard Test Methods forFire Tests of Fire-Resistive Barrier Systems for ElectricalSystem Components1This standard is issued under the fixed designation E 1725; the number immediately following the designation indicates the year

2、 oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTEThe fire-test-response caveat was updated in October 2004.1.

3、Scope1.1 These test methods cover fire-test-response.1.2 These fire-test-response test methods provide informa-tion on the temperatures recorded on the electrical systemcomponent within a fire-resistive barrier system during theperiod of exposure.1.3 This standard is used to measure and describe the

4、response of materials, products, or assemblies to heat andflame under controlled conditions, but does not by itselfincorporate all factors required for fire hazard or fire riskassessment of the materials, products, or assemblies underactual fire conditions.1.4 Potentially important factors and fire

5、characteristics notaddressed by these test methods include, but are not limited to:1.4.1 The performance of the fire-resistive barrier systemconstructed with components other than those tested.1.4.2 An evaluation of the functionality of the electricalsystem within the fire-resistive barrier system.1

6、.4.3 An evaluation of the ampacity of the electrical systemwithin the fire-resistive barrier system.1.4.4 An evaluation of the smoke, toxic gases, corrosivity,or other products of heating.1.4.5 A measurement of the flame spread characteristicsover the surface of the fire-resistive barrier system.1.4

7、.6 An evaluation of through-penetration sealing methods.1.4.7 Combustibility of materials in the fire-resistive barriersystem or of the electrical system components.1.4.8 The need for supports beyond those normally re-quired.1.4.9 Environmental conditions in the area of service.1.5 The values stated

8、 in inch-pound units are to be regardedas the standard. The SI units given in parentheses are forinformation only.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate s

9、afety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E 119 Test Methods for Fire Tests of Building Constructionand MaterialsE 176 Terminology of Fire StandardsE 1529 Test Methods for Determining Effects of Large

10、Hydrocarbon Pool Fires on Structural Members and As-semblies3. Terminology3.1 Definitions:3.1.1 air droplengths of open run conductors or cablessupported only at each end.3.1.2 electrical system componentscable trays, conduitsand other raceways, open run cables and conductors, cables,conductors, cab

11、inets, and other components, as defined or usedin the National Electrical Code, and air drops as defined in3.1.1.3.1.3 fire-resistive barrier systema specific constructionof devices, materials, or coatings installed around, or appliedto, the electrical system components.3.1.4 specimena construction

12、consisting of electrical sys-tem components and a fire-resistive barrier system.3.1.5 test assemblyhorizontal or vertical construction onwhich test specimens are to be mounted together with associ-ated instrumentation.4. Significance and Use4.1 These fire-test-response test methods evaluate, under t

13、hespecified test conditions, the ability of a fire-resistive barriersystem to inhibit thermal transmission to the electrical systemcomponent within.4.2 In these procedures, the specimens are subjected to oneor more specific sets of laboratory test conditions. If different1These test methods are unde

14、r the jurisdiction of ASTM Committee E05 on FireStandards and are the direct responsibility of Subcommittee E05.11 on ConstructionAssemblies.Current edition approved Aug. 15, 1995. Published October 1995.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Se

15、rvice at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.test conditions are substituted or the end

16、-use conditions arechanged, it may not be possible by or from these test methodsto predict changes in the fire test response characteristicsmeasured. Therefore, the results are valid only for the fire testexposure conditions described in these procedures.4.3 These test methods provide a measurement

17、of thetransmission of heat to the electrical system components withinthe barrier system.4.4 These test methods provide qualification of a fireresis-tive barrier system as one element of an electrical systemdesigned to maintain continuous operation of critical functionsand processes for a specific fi

18、re endurance rating.4.4.1 In addition to the temperature data provided by thesetest methods, numerous other factors, such as referenced in 1.4shall be considered in specifying such a system.5. Control of Fire Test5.1 Fire Test Exposure Conditions:5.1.1 Time-Temperature CurveMaintain the fire environ

19、-ment within the furnace in accordance with the standardtime-temperature curve shown in Test Method E 119 or therapid temperature rise curve shown in Test Method E 1529.5.2 Furnace Temperatures:5.2.1 The temperature fixed by the curve shall be theaverage temperature obtained from readings of thermoc

20、ouplesdistributed within the test furnace. Disperse the thermocouplesas symmetrically as possible within the furnace to measure thetemperature near all exterior surfaces of the specimen. Do notplace the thermocouples at locations where temperature read-ings would be effected by drafts within the fur

21、nace.5.2.2 Measure and report the temperatures at intervals notexceeding 1 min.5.3 Furnace Thermocouples:5.3.1 Test Method E 119Enclose the thermocouples insealed protection tubes of such materials and dimensions thatthe time constant of the protected thermocouple assembly lieswithin the range from

22、300 to 400 s3. The exposed length of thepyrometer tube and thermocouple in the furnace chamber shallbe not less than 12 in. (305 mm).5.3.2 Test Methods E 1529Measure the temperature of thegases adjacent to and impinging on the test specimens usingfactory manufactured 0.25-in. (6-mm) outside diameter

23、 (OD),Inconel4-sheathed, Type K, chromel-alumel4thermocouples.The time constant, in air, of the thermocouple assemblies shallbe less than 60 s. Use standard calibration thermocouples withan accuracy of 6 0.75 %. A minimum length of 20 diameters(125 mm) of the sheathed junction end of the thermocoupl

24、eshall be mounted parallel to the surface of the test specimen.5.4 Furnace Thermocouple LocationsPosition the furnacecontrol thermocouples before the start of the fire exposure test.It shall be permitted to move the thermocouple to avoidtouching the specimen as a result of its deflection during thet

25、est.5.4.1 Place the junction of each thermocouple 12 6 1 in.(305 6 25 mm) from the surface of horizontal constructions or12 6 1 in. from the surface of specimens mounted in horizontalconstructions.5.4.2 Place the junction of each thermocouple 6 6 1 in. (1526 25 mm) from the surface of vertical const

26、ructions or 6 6 1in. from the surface of specimens mounted in vertical construc-tions.5.4.3 Use a minimum of three thermocouples.5.4.3.1 For specimens mounted in horizontal constructions,there shall be no less than five thermocouples per 100 ft2(9 m2)of exposed area. Calculate the exposed area to be

27、 the sum ofthe exterior surface area of the fire-resistive barrier system plusthe area of the horizontal construction exposed to the furnacefire.5.4.3.2 For specimens mounted in vertical constructions,there shall be no less than nine thermocouples per 100 ft2(9m2) of exposed area. Calculate the expo

28、sed area to be the sumof the exterior surface area of the fire resistive barrier systemplus the area of the vertical construction exposed to the furnacefire.5.5 Furnace Control:5.5.1 Test Method E 119 Time-Temperature Curve:5.5.1.1 The control of the furnace control shall be such thatthe area under

29、the time-temperature curve, obtained by aver-aging the results from the furnace thermocouple readings, iswithin 10 % of the corresponding area under the standardtime-temperature curve for fire tests of1horless duration,within 7.5 % for those over 1 h and not more than 2 h, andwithin 5 % for tests ex

30、ceeding2hinduration.5.5.2 Test Method E 1529 Time-Temperature CurveThecontrol of the furnace shall be such that the area under thetime-temperature curve of the average of the gas temperaturemeasurements is within 10 % of the corresponding curvedeveloped in the furnace calibration for tests of 30 min

31、 or lessduration, within 7.5 % of those over 30 min and not more than1 h, and within 5 % for tests exceeding 1 h.5.5.3 If the indicated rating for the protection system is 60min or more, it shall be increased or decreased by the followingcorrection to compensate for significant variation of the mea-

32、sured furnace temperature from the standard time-temperaturecurve. The correction is to be expressed by the followingformula:C 5 2IA 2 As3As1 L!(1)where:C = correction in the same units at I,I = indicated fire resistance period,3A typical thermocouple meeting these time-constant requirements may bef

33、abricated by fusion-welding the twisted ends of No. 18 B maintain this heat flux for the duration of thetest.5.6.4 The temperature of the environment that generates theheat flux of 50 000 Btu/ft2h shall be at least 1500F (815C)after the first 3 min of the test and shall be between 1850F(1010C) and 2

34、150F (1180C) at all times after the first 5 minof the test.5.7 Furnace PressureThe furnace pressure control de-scribed in the sections that follow pertain to tests performedusing either of the two time-temperature curves.5.7.1 Measure the pressure differential between the labora-tory ambient air and

35、 the interior of the fire test furnace with aminimum of two pressure probes.5.7.1.1 The pressure measuring probe tips shall be either ofthe “T” type as shown in Fig. 1, or of the “tube” type as shownin Fig. 2, and shall be manufactured from stainless steel orother suitable material.5.7.2 Horizontal

36、Test AssemblyMaintain the differentialpressure at neutral at a point not less than 12 in. (305 mm)below the exposed surface of the test assembly. No specimenshall be positioned within the heated area of the furnace suchthat the entire exposed vertical dimension lies below theneutral pressure plane.F

37、IG. 1 Furnace Pressure Probe 1E 1725 95 (2001)e135.7.2.1 Locate the pressure measuring probe tips within 6in. of the vertical centerline of the test specimen. Separate theprobes by a minimum of one third of the longest insidedimension of the test furnace. Alternatively, separate the twoprobes by a m

38、inimum of 12 in. (305 mm) vertical distancewithin the furnace, and the location of the neutral planecalculated as a function of their vertical separation and theirpressure difference.5.7.3 Vertical Test AssemblyPosition specimens withinthe heated area of the furnace such that at least one half of th

39、evertical dimension lies above the neutral pressure plane.5.7.3.1 Separate at least two probes by a vertical distancewithin the furnace equal to one half the furnace height or 12 in.(305 mm), whichever is greatest, and calculate the location ofthe neutral plane as a function of their vertical separa

40、tion andtheir pressure difference.5.7.4 Measure the pressure by means of a manometer orpressure transducer. The manometer or transducer shall becapable of reading 0.01 in. water (2.5 Pa), with a measurementprecision of 0.005 in. water (1.25 Pa).6. Specimen Construction6.1 Construct the horizontal or

41、 vertical test assembly ofmaterials that offer adequate support for the test specimenduring the fire exposure. The designs and installation of thefire-resistive barrier systems and electrical system componentsshall be representative of actual end use.6.2 Electrical System ComponentsTest components a

42、ttheir full size and linear dimensions for which evaluation isdesired. If the full-size components linear dimensions aregreater than those specified under each component type in thissection, utilize the dimensions shown, unless data is requiredfor a unique design. Cable trays, conduits, and other ra

43、cewaysare tested without conductors, unless the test is for a uniquedesign. Suggested arrangements are shown in Figs. 3 and 4.6.2.1 Cable Trays, Raceways, and Open-Run CablesHorizontal Assemblies:6.2.1.1 The exposed vertical depth of the test specimen shallnot be less than 36 in. (914 mm).6.2.1.2 Th

44、e exposed horizontal length between the insidesurfaces of the vertical sections shall not be less than 60 in.(1524 mm).6.2.2 Cable Trays, Raceways, and Open-Run CablesVertical Assemblies:6.2.2.1 The exposed vertical height of the test specimenshall not be less than 60 in. (1524 mm).6.2.2.2 The expos

45、ed horizontal depth between the verticaltest assembly and the closest surface of the vertical specimenshall not be less than 36 in. (914 mm).6.2.3 Airdrop:FIG. 2 Furnace Pressure Probe 2E 1725 95 (2001)e14FIG. 3 Standard Electrical Component AssemblyFIG. 4 Unique Electrical Component AssemblyE 1725

46、95 (2001)e156.2.3.1 To evaluate an airdrop in the vertical configurationonly, the exposed vertical length of the test specimen shall notbe less than 24 in. (610 mm) (see Fig. 5).6.2.3.2 To evaluate an airdrop in the horizontal configura-tion only, the exposed horizontal length shall not be less than

47、24 in. (610 mm).6.2.3.3 To evaluate an airdrop for both vertical and horizon-tal with a bend, the exposed vertical length shall not be lessthan 24 in. (610 mm) and the exposed horizontal length shallnot be less than 24 in. (see Fig. 6).6.2.4 Cabinets (Junction and Pull Boxes)Test these itemsat their

48、 full dimensions for which evaluation is desired.6.3 Provide assembly with through-penetration fire stopsand internal specimen seals. Construct these using materialsand techniques capable of withstanding the fire exposure test.Internal seals in cable trays and raceways shall be required inorder to e

49、liminate convective cooling of the test specimen.6.4 Locate the periphery of the specimen not closer than 12in. (305 mm) from the inside furnace edge and maintain aminimum separation distance between adjacent test specimensof 12 in. unless it is documented that closer placement does notaffect the results.7. Conditioning7.1 Establish a moisture equilibrium resulting from thedrying of the specimen(s) and test assembly in air having 50 65 % relative humidity at 73 6 5F (23 6 3C) prior to testing.When impractical to achieve this condition, the tests areperm