1、Designation: E1725 14 An American National StandardStandard Test Methods forFire Tests of Fire-Resistive Barrier Systems for ElectricalSystem Components1This standard is issued under the fixed designation E1725; the number immediately following the designation indicates the year oforiginal adoption
2、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. Scope*1.1 These test methods cover fire-test-response.1.2 These fire-test-response tes
3、t 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 theresponse of materials, products, or assemblies to heat andflame under controlled cond
4、itions, 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 characteristics notaddressed by these test methods include, but are not limited to:1.
5、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.1.4.3 An evaluation of the ampacity of the electrical systemwithin the fire-resistive
6、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.1.4.6 An evaluation of through-penetration sealing methods.1.4.7 Combustibility of mater
7、ials 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 in inch-pound units are to be regardedas standard. The values given in parentheses a
8、re mathematicalconversions to SI units that are provided for information onlyand are not considered standard.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 safety
9、 and health practices and determine the applica-bility of regulatory limitations prior to use.1.7 Fire testing is inherently hazardous. Adequate safe-guards for personnel and property shall be employed inconducting these tests.2. Referenced Documents2.1 ASTM Standards:2E119 Test Methods for Fire Tes
10、ts of Building Constructionand MaterialsE1529 Test Methods for Determining Effects of Large Hy-drocarbon Pool Fires on Structural Members and Assem-blies3. Terminology3.1 Definitions:3.1.1 air droplengths of open run conductors or cablessupported only at each end.3.1.2 electrical system componentsca
11、ble trays, conduitsand other raceways, open run cables and conductors, cables,conductors, cabinets, 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 construction ofdevices, materials, or coatings i
12、nstalled around, or applied to,the electrical system components.3.1.4 specimena construction 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 instr
13、umentation.1These test methods are under the jurisdiction of ASTM Committee E05 on FireStandards and are the direct responsibility of Subcommittee E05.11 on FireResistance.Current edition approved July 1, 2014. Published August 2014. Originallyapproved in 1995. Last previous edition approved in 2008
14、 as E172508. DOI:10.1520/E1725-14.2For 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.*A Summary of Changes secti
15、on appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14. Significance and Use4.1 These fire-test-response test methods evaluate, under thespecified test conditions, the ability of a fire-resistive barri
16、ersystem 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 differenttest conditions are substituted or the end-use conditions arechanged, it is not always possibl
17、e 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 of thetransmission of heat to the electrical syst
18、em 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 fire resistance rating.4.4.1 In addition to the tem
19、perature 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-ment within the furnace in accordance with the
20、standardtime-temperature curve shown in Test Method E119 or therapid temperature rise curve shown in Test Method E1529.5.2 Furnace Temperatures:5.2.1 The temperature fixed by the curve shall be theaverage temperature obtained from readings of thermocouplesdistributed within the test furnace. Dispers
21、e 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 furnace.5.2.2 Measure and report the temperatures at
22、intervals notexceeding 1 min.5.3 Furnace Thermocouples:5.3.1 Test Method E119Enclose the thermocouples insealed protection tubes of such materials and dimensions thatthe time constant of the protected thermocouple assembly lieswithin the range from 300 to 400 s3. The exposed length of thepyrometer t
23、ube and thermocouple in the furnace chamber shallbe not less than 12 in. (305 mm).5.3.2 Test Methods E1529Measure the temperature of thegases adjacent to and impinging on the test specimens usingfactory manufactured 0.25-in. (6-mm) outside diameter (OD),Inconel4-sheathed, Type K, chromel-alumel4ther
24、mocouples.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 thermocoupleshall be mounted parallel to the surface of the tes
25、t 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 thetest.5.4.1 Place the junction of each thermocouple 12
26、 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 constructions or 6 6 1in. from the surface of specimens m
27、ounted 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 the sum ofthe exterior surface area of the fire-res
28、istive 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 exposed area to be the sumof the exterior surface area o
29、f the fire resistive barrier systemplus the area of the vertical construction exposed to the furnacefire.5.5 Furnace Control:5.5.1 Test Method E119 Time-Temperature Curve:5.5.1.1 The control of the furnace control shall be such thatthe area under the time-temperature curve, obtained by aver-aging th
30、e 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 exceeding2hinduration.5.5.2 Test Method E1529 Time-Temp
31、erature 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 or lessduration, within 7.5 % of those over 30 min an
32、d 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 following3A typical thermocouple meeting these time-constant requirements may befabricated by fusion-welding the twisted ends
33、 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 2150F (1180C) at all times after the first 5
34、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 the interior of the fire test furnace with
35、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 Test AssemblyMaintain the differentialpressu
36、re 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.5.7.2.1 Locate the pressure measuring probe t
37、ips 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 minimum of 12 in. (305 mm) vertical distancewithin the furnace, and the location of the neutral
38、 planecalculated as a function of their vertical separation and theirpressure difference.5.7.3 Vertical Test AssemblyPosition specimens within theheated area of the furnace such that at least one half of thevertical dimension lies above the neutral pressure plane.5.7.3.1 Separate at least two probes
39、 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 separation andtheir pressure difference.5.7.4 Measure the pressure by means of a manometer orpressur
40、e 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 vertical test assembly ofmaterials that offer adequate support for the test specimenduring th
41、e 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 attheir full size and linear dimensions for which evaluation isdesired. If the full-size compon
42、ents 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 racewaysare tested without conductors, unless the test is for a uniquedesign. Suggested arrangem
43、ents 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 The exposed horizontal length between the insidesurfaces of the vertical sections shall not be l
44、ess 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 exposed horizontal depth between the verticaltest assembly and the closest surface of the vertical
45、specimenshall not be less than 36 in. (914 mm).6.2.3 Airdrop:6.2.3.1 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
46、 exposed horizontal length shall not be less than24 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 lessE1725 143than 24 in. (610 mm) and the exposed horizontal length shallnot be less than 24 in. (see Fig. 6).6.2.4
47、Cabinets (Junction and Pull Boxes)Test these itemsat their 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
48、in cable trays and raceways shall be required inorder to eliminate 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
49、 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 arepermitted to be conducted when the dampest portion of thefire-resistive barrier system or test assembly has achieved anequilibrium moisture condition corresponding to drying in airhaving 50 6 5 % relative humidity at 73 6 5F (23 6 3C).The specimen
