1、Designation: D1048 12Standard Specification forRubber Insulating Blankets1This standard is issued under the fixed designation D1048; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses
2、 indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This specification covers acceptance testing of rubberinsulating blankets f
3、or protection of workers from accidentalcontact with live electrical conductors, apparatus, or circuits.1.2 Two types of blankets are provided and are designatedas Type I, not resistant to ozone, and Type II, resistant to ozone.1.3 Five classes of blankets, differing in electricalcharacteristics, ar
4、e provided and are designated as Class 0,Class 1, Class 2, Class 3, and Class 4.1.4 Two styles of blankets, differing in constructioncharacteristics, are provided and are designated as Style A andStyle B.1.5 The following safety hazards caveat pertains only to thetest method portion, Sections 16-19,
5、 of this specification: Thisstandard does not purport to address all of the safety concerns,if any, associated with its use. It is the responsibility of the userof this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions prior to us
6、e.2. Referenced Documents2.1 ASTM Standards:2D149 Test Method for Dielectric Breakdown Voltage andDielectric Strength of Solid Electrical Insulating Materialsat Commercial Power FrequenciesD297 Test Methods for Rubber ProductsChemical Analy-sisD412 Test Methods for Vulcanized Rubber and Thermoplas-t
7、ic ElastomersTensionD518 Test Method for Rubber DeteriorationSurfaceCracking (Withdrawn 2007)3D570 Test Method for Water Absorption of PlasticsD573 Test Method for RubberDeterioration in an AirOvenD624 Test Method for Tear Strength of Conventional Vul-canized Rubber and Thermoplastic ElastomersD1388
8、 Test Method for Stiffness of FabricsD2865 Practice for Calibration of Standards and Equipmentfor Electrical Insulating Materials TestingF819 Terminology Relating to Electrical Protective Equip-ment for Workers2.2 American National Standards:ANSI/IEEE C 2 National Electrical Safety Code4C84.1 Electr
9、ic Power Systems and EquipmentVoltageRatings (60 Hz)53. Terminology3.1 beaded edge a narrow border of thicker rubber whichextends completely around the outer edges of the blanket.3.2 breakdownthe electrical discharge or arc occurringbetween the electrodes and through the equipment being tested.3.3 d
10、esignated personan individual who is qualified byexperience or training to perform an assigned task.3.4 electrical testing facilitya location with qualifiedpersonnel, testing equipment, and procedures for the inspectionand electrical testing of electrical insulating protective equip-ment.3.5 electro
11、de clearancethe shortest path from the ener-gized electrode to the ground electrode.3.6 flashoverthe electrical discharge or arc occurring be-tween electrodes and over or around, but not through, theequipment being tested.3.7 insulatedseparated from other conducting surfaces bya dielectric substance
12、 (including air space) offering a highresistance to the passage of current.1This specification is under the jurisdiction of ASTM Committee F18 onElectrical Protective Equipment for Workers and is the direct responsibility ofSubcommittee F18.25 on Insulating Cover-Up Equipment. This standard replaces
13、ANSI Standard J 6.4, which is no longer available.Current edition approved Oct. 1, 2012. Published October 2012. Originallyapproved in 1949 as D1048 49 T. Last previous edition approved in 2011 asD1048-11. DOI: 10.1520/D1048-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or
14、contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from Institute of Electrical and Elect
15、ronics Engineers, Inc. (IEEE),445 Hoes Ln., P.O. Box 1331, Piscataway, NJ 08854-1331, http:/www.ieee.org.5Available from National Electrical ManufacturersAssociation, 1300 North 17thStreet, Rosslyn, VA 22209.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 1942
16、8-2959. United States13.7.1 DiscussionWhen any object is said to be insulated, itis understood to be insulated in a suitable manner for theconditions to which it is subjected. Otherwise, it is, within thepurpose of this definition, uninsulated. Insulating covering ofconductors is one means of making
17、 this conductor insulated.3.8 ozonea very active form of oxygen that may beproduced by corona, arcing, or ultra-violet rays.3.9 ozone cutting and checking cracks produced by ozonein a material under mechanical stress.3.10 rubbera generic term that includes elastomers andelastomer compounds regardles
18、s of origin.3.11 userthe employer or entity purchasing the equipmentto be utilized by workers for their protection; in the absence ofsuch an employer or entity, the individual purchasing orutilizing the protective equipment.3.12 voltage, maximum retestvoltage, either ac rms or dcavg, that is equal t
19、o the proof-test voltage for new protectiveequipment.3.13 voltage, retestvoltage, either ac rms or dc avg, thatused protective equipment must be capable of withstanding fora specified test period without breakdown.3.14 voltage, nominal designa nominal value consistentwith the latest revision of ANSI
20、 C84.1, assigned to the circuitor system for the purpose of conveniently designating itsvoltage class.3.15 voltage, maximum usethe ac voltage, (rms), classifi-cation of the protective equipment that designates the maxi-mum nominal design voltage of the energized system that maybe safely worked. The
21、nominal design voltage is equal tophase-to-phase voltage on multiphase circuits.3.15.1 If there is no multiphase exposure in a system area,and the voltage exposure is limited to phase (polarity on dcsystems) to ground potential, the phase (polarity on dc sys-tems) to ground potential shall be consid
22、ered to be the nominaldesign voltage.3.15.2 If electrical equipment and devices are insulated orisolated, or both, such that the multiphase exposure on agrounded wye circuit is removed, then the nominal designvoltage may be considered as the phase-to-ground voltage onthat circuit.NOTE 1The work prac
23、tices and methods associated with removingmultiphase exposures at any given work site are not addressed in thisspecification. Users should refer to ANSI C2, National Electrical SafetyCode, Section 44, for proper work practices.3.16 For definitions of other terms, refer to TerminologyF819.4. Signific
24、ance and Use4.1 This specification covers the minimum electrical,chemical, and physical properties guaranteed by the manufac-turer and the detailed procedures by which such properties areto be determined. The purchaser may, at his option, perform orhave performed any of these tests in order to verif
25、y theguarantee. Claims for failure to meet the specification aresubject to verification by the manufacturer.4.2 Blankets are used for personal protection; therefore,when authorizing their use, a margin of safety shall be providedbetween the maximum voltage at which they are used and theproof-test vo
26、ltage at which they are tested. The relationshipbetween proof-test voltage and the nominal maximum voltageat which blankets shall be used is shown in Table 1.4.3 Work practices vary from user to user depending uponmany factors. These factors may include, but are not limited to,operating system volta
27、ges, construction design, work proce-dures and techniques, weather conditions, etc. Therefore,except for the restrictions set forth in this specification becauseof design limitations, the use and maintenance of this equip-ment is beyond the scope of this specification.4.3.1 It is common practice and
28、 the responsibility of the userof this type of protective equipment to prepare completeinstructions and regulations to govern the correct and safe useof such equipment.5. Classification5.1 Blankets covered under this specification shall be des-ignated as Type I or Type II; Class 0, Class 1, Class 2,
29、 Class 3,or Class 4; Style A or Style B.5.1.1 Type I, non-resistant to ozone, made from a high-gradecis-1,4-polyisoprene rubber compound of natural or syntheticorigin, properly vulcanized.5.1.2 Type II, ozone resistant, made of any elastomer orcombination of elastomeric compounds.5.1.3 The class des
30、ignation shall be based on the electricalproperties as shown in Table 1 and Table 2.5.1.4 Style A, constructed of the elastomers indicated underType I or Type II, shall be free of any reinforcement.5.1.5 Style B, constructed of the elastomers indicated underType I or Type II, shall incorporate a rei
31、nforcement; thisreinforcement shall not adversely affect the dielectric charac-teristics of the blankets.6. Ordering Information6.1 Orders for blankets under this specification shouldinclude the following information:6.1.1 Type,6.1.2 Class,6.1.3 Style,6.1.4 Size,6.1.5 Eyelets, and6.1.6 Color.TABLE 1
32、 Proof-Test/Use Voltage RelationshipClass of Insu-lating BlanketsNominal MaximumUse VoltageAPhase-Phase, ac,rms, maxAC Proof-TestVoltage, rms VDC Proof-TestVoltage, avg, V0 1 000 5 000 20 0001 7 500 10 000 40 0002 17 000 20 000 50 0003 26 500 30 000 60 0004 36 000 40 000 70 000AExcept for Class O eq
33、uipment, the maximum use voltage is based on thefollowing formula:Maximum use voltage (maximum nominal design voltage) 0.95 ac proof-testvoltage 2000D1048 1226.2 The listing of types, classes, styles, sizes, and eyelets isnot intended to mean that all shall necessarily be available frommanufacturers
34、; it signifies only that, if made, they shallconform to the details of this specification.7. Manufacture and Marking7.1 The blankets shall be produced by a seamless vulcaniz-ing process.7.2 Where eyelets are specified, each blanket shall beequipped with nonmetallic eyelets.7.3 Each blanket shall be
35、marked clearly and permanentlywith the name of the manufacturer or supplier, ASTM D1048,type, class, and style.7.3.1 Blankets may be marked by either molding the infor-mation directly into the blanket or by use of a label; eithermethod is equally acceptable. The method shall be at thediscretion of t
36、he manufacturer. If a label is used the color shallbe that specified for each voltage class; Class 0red, Class1white, Class 2yellow, Class 3green, and Class4orange.7.4 Blankets shall have a smooth, flat finish and beadededges.8. Chemical and Physical Requirements8.1 The blanket material shall confor
37、m to the physicalrequirements in Table 3 and the accelerated aging in 19.2.7.8.2 For Type I blankets, the rubber polymer may be deter-mined in accordance with 19.1.1. This shall be the referee testif a dispute exists between the manufacturer and purchaserregarding the elastomer content of Type I bla
38、nkets.8.3 The Type II blanket material shall show no visibleeffects from ozone when tested in accordance with 18.6. Anyvisible signs of ozone deterioration, such as checking,cracking, breaks, pitting, etc., shall be considered as evidenceof failure to meet the requirements of Type II blankets. In ca
39、seof dispute, Method A of the ozone resistance test shall be thereferee test.9. Electrical Requirements9.1 Each blanket shall be given a proof test and shallwithstand the 60-Hz ac proof-test voltage (rms value) or the dcproof-test voltage (average value) specified in Table 2. Theproof test shall be
40、performed in accordance with Section 18and shall be conducted continuously for at least 3 min.9.2 The blanket material shall show a 60-Hz dielectricstrength of not less than 14.8 MV/m (375 V-rms/mil) ofspecimen thickness for each individual test, when tested inaccordance with 18.5.10. Dimensions and
41、 Permissible Variations10.1 Length and Width The length and width of theblankets shall be specified on the purchase order. Somestandard sizes are as shown in Table 4. Permissible variationsfrom the specified length and width shall be 613 mm (60.5in.) except for the 1160 by 1160-mm (45.5 by 45.5-in.)
42、 slottedsize for which the permissible variation shall be 625 mm(61.0 in.).TABLE 2 Electrical Proof-TestsClassAC DCProof-Test Voltage,rms,VNominal ElectrodeClearancesA Proof-Test Voltages,Bavg, VNominal ElectrodeClearancesAmm in. mm in.0 5 000 76 3 20 000 76 31 10 000 76 3 40 000 76 32 20 000 127 5
43、50 000 152 63 30 000 178 7 60 000 203 84 40 000 254 10 70 000 305 12AThese nominal clearances are intended to avoid flashover and may be increased by no more than 51 mm (2 in.) when required by a change in atmospheric conditionsfrom the standard of 100 kPa (1 atm) barometric pressure and average hum
44、idity conditions. These clearances may be decreased if atmospheric conditions permit.BDC proof-test voltages were determined using negative polarity.TABLE 3 Physical RequirementsType I Type IIStyle ABlanketStyle BBlanketStyle ABlanketTensile strength, min, Die C,MPa (psi)17.2 (2500) 17.2 (2500) 10.3
45、 (1500)Elongation, min, % 500 500 500Tension set, max, mm (in.) 6.4 (0.25) 6.4 (0.25) 6.4 (0.25)Tear resistance, min, kN/m(lbf/in.)21 (120) 26 (150) 16 (90)Puncture resistance, min,kN/m (lbf/in.)18 (100) 26 (150) 18 (100)Drape stiffness, max at25C (77F), mm (in.)89 (3.5) 89 (3.5) 89 (3.5)Drape stiff
46、ness, max at10C (14F), mm (in.)110 (4.5) 110 (4.5) 110 (4.5)Flex stiffness, max at 25C(77F), Nm (in.lbf)0.028 (0.25) 0.028 (0.25) 0.028 (0.25)Flex stiffness, max at 10C(14F), Nm (in.lbf)0.034 (0.30) 0.034 (0.30) 0.034 (0.30)Moisture absorption, max, % 1.5 3.0 2.0TABLE 4 Standard Blanket SizesLength
47、and WidthWithout Slot mm (in.)457 by 910 (18 by 36)560 by 560 (22 by 22)690 by 910 (27 by 36)910 by 910 (36 by 36)910 by 2128 (36 by 84)1160 by 1160 (45.5 by 45.5)With Slot mm (in.)560 by 560 (22 by 22)910 by 910 (36 by 36)1160 by 1160 (45.5 by 45.5)D1048 12310.2 ThicknessSee Table 5.10.2.1 Manufact
48、urers must meet the minimum thicknessrequirements for each Class of blanket as specified in Table 5.The manufacturer may label a blanket lower than actual Classvalue if so specified by the purchaser.10.3 Bead on Edge The bead shall be not less than 8 mm(0.31 in.) wide nor less than 1.5 mm (0.06 in.)
49、 high.10.4 EyeletsIf other than manufacturers standard is de-sired; the number, size, and type of eyelet shall be given on thepurchase order. The eyelets shall not be less than 8 mm (0.31in.) in diameter.10.5 No eyelets, holes, or slots are permitted in a blanketwhich will reduce the test electrode clearance to less than thevalues listed in Table 2.11. Workmanship and Finish11.1 The blankets shall be free of harmful physicalirregularities, which can be detected by thorough test orinspection.11.1.1 Harmful physical irregularities m
