1、Designation: D 1048 05Standard Specification forRubber Insulating Blankets1This standard is issued under the fixed designation D 1048; 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 parenthes
2、es indicates the year of last reapproval. Asuperscript epsilon (e) 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 blanket
3、s for 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 electrical charac-teristic
4、s, are provided and are designated as Class 0, Class 1,Class 2, Class 3, and Class 4.1.4 Two styles of blankets, differing in construction charac-teristics, are provided and are designated as Style A and StyleB.1.5 The following safety hazards caveat pertains only to thetest method portion, Sections
5、 16-19, 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 prio
6、r to use.2. Referenced Documents2.1 ASTM Standards:2D 149 Test Method for Dielectric Breakdown Voltage andDielectric Strength of Solid Electrical Insulating Materialsat Commercial Power FrequenciesD 297 Test Methods for Rubber ProductsChemicalAnalysisD 412 Test Methods for Vulcanized Rubber and Ther
7、mo-plastic Rubbers and Thermoplastic ElastomersTensionD 518 Test Method for Rubber DeteriorationSurfaceCrackingD 570 Test Method for Water Absorption of PlasticsD 573 Test Method for RubberDeterioration in an AirOvenD 624 Test Method for Tear Strength of ConventionalVulcanized Rubber and Thermoplast
8、ic ElastomersD 1388 Test Methods for Stiffness of FabricsD 2865 Practice for Calibration of Standards and Equip-ment for Electrical Insulating Materials TestingF 819 Terminology Relating to Electrical Protective Equip-ment for Workers2.2 American National Standards:C 2 National Electrical Safety Cod
9、e, Section 443C39.5 Safety Requirements for Electrical and ElectronicMeasuring and Controlling Instrumentation3C84.1 Voltage Ratings for Electric Power Systems andEquipment (60 Hz)33. Terminology3.1 beaded edge a narrow border of thicker rubber whichextends completely around the outer edges of the b
10、lanket.3.2 breakdownthe electrical discharge or arc occurringbetween the electrodes and through the equipment being tested.3.3 designated personan individual who is qualified byexperience or training to perform an assigned task.3.4 electrical testing facilitya location with qualified per-sonnel, tes
11、ting equipment, and procedures for the inspectionand electrical testing of electrical insulating protective equip-ment.3.5 electrode clearancethe shortest path from the ener-gized electrode to the ground electrode.3.6 flashoverthe electrical discharge or arc occurringbetween electrodes and over or a
12、round, but not through, theequipment being tested.3.7 insulatedseparated from other conducting surfaces bya dielectric substance (including air space) offering a highresistance to the passage of current.3.7.1 DiscussionWhen any object is said to be insulated,it is understood to be insulated in a sui
13、table 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 this conductor insulated.1This specification is under the jurisdiction of ASTM Committee F18 onElectrical Protective E
14、quipment for Workers and is the direct responsibility ofSubcommittee F18.25 on Insulating Cover-up Equipment. This standard replacesANSI Standard J 6.4, which is no longer available.Current edition approved Feb. 1, 2005. Published March 2005. Originallyapproved in 1949 as D 1048 49 T. Last previous
15、edition approved in 1999 asD 1048 99.2For 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.3Available fromAmerican
16、National Standards Institute, 25 West 43rd Street, 4thFloor, New York, NY 10036.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.8 ozonea very active form of oxygen that may beproduced by corona, arcing, or ultra-violet rays.3.9 ozo
17、ne cutting and checkingcracks produced by ozonein a material under mechanical stress.3.10 rubbera generic term that includes elastomers andelastomer compounds regardless of origin.3.11 userthe employer or entity purchasing the equipmentto be utilized by workers for their protection; in the absence o
18、fsuch an employer or entity, the individual purchasing orutilizing the protective equipment.3.12 voltage, maximum retestvoltage, either ac rms or dcavg, that is equal to the proof-test voltage for new protectiveequipment.3.13 voltage, retestvoltage, either ac rms or dc avg, thatused protective equip
19、ment must be capable of withstanding fora specified test period without breakdown.3.14 voltage, nominal designa nominal value consistentwith the latest revision of ANSI C84.1, assigned to the circuitor system for the purpose of conveniently designating itsvoltage class.3.15 voltage, maximum usethe a
20、c voltage, (rms), classi-fication of the protective equipment that designates the maxi-mum nominal design voltage of the energized system that maybe safely worked. The nominal design voltage is equal tophase-to-phase voltage on multiphase circuits.3.15.1 If there is no multiphase exposure in a syste
21、m 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 considered to be the nominaldesign voltage.3.15.2 If electrical equipment and devices are insulated orisolated, or both, such that the mul
22、itphase 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 practices and methods associated with removingmultiphase exposures at any given work site are not addressed in thisspecification. Users
23、should refer to ANSI C2, National Electrical SafetyCode, Section 44, for proper work practices.3.16 For definitions of other terms, refer to TerminologyF 819.4. Significance and Use4.1 This specification covers the minimum electrical,chemical, and physical properties guaranteed by the manufac-turer
24、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 verify theguarantee. Claims for failure to meet the specification aresubject to verification by the manufacturer.4.2 Blankets are used f
25、or 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 voltage at which they are tested. The relationshipbetween proof-test voltage and the nominal maximum voltageat which blankets shall b
26、e 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 voltages, construction design, work proce-dures and techniques, weather conditions, etc. Therefore,except for the restrictions set forth
27、 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 the responsibility of the userof this type of protective equipment to prepare completeinstructions and regulations to govern the c
28、orrect 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, 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 com
29、pound 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 designation shall be based on the electricalproperties as shown in Table 1 and Table 2.5.1.4 Style A, constructed of the elastomers in
30、dicated 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 reinforcement; thisreinforcement shall not adversely affect the dielectric charac-teristics of the blankets.6. Ordering Information6.1
31、 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.6.2 The listing of types, classes, styles, sizes, and eyelets isnot intended to mean that all shall necessarily be available frommanufactu
32、rers; it signifies only that, if made, they shallconform to the details of this specification.TABLE 1 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
33、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 equipment, the maximum use voltage is based on thefollowing formula:Maximum use voltage (maximum nominal design voltage) 0.95 ac proof-testvoltage 2000D 1048 0527. Manufacture and Marking7.1 The blanke
34、ts 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 marked clearly and permanentlywith the name of the manufacturer or supplier, ASTM D1048,type, class, and style.7.3.1 Blankets may
35、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 the manufacturer. If a label is used the color shallbe that specified for each voltage class; Class 0red, Class1white, Class 2yello
36、w, 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 conform 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 de
37、ter-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 blankets.8.3 The Type II blanket material shall show no visibleeffects from ozone when tested in accordance with 18.6. Anyvisible sig
38、ns of ozone deterioration, such as checking, crack-ing, breaks, pitting, etc., shall be considered as evidence offailure to meet the requirements of Type II blankets. In case ofdispute, Method A of the ozone resistance test shall be thereferee test.9. Electrical Requirements9.1 Each blanket shall be
39、 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 performed in accordance with Section 18and shall be conducted continuously for at least 3 min.9.2 The blanket material shall sho
40、w 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 Permissible Variations10.1 Length and Width The length and width of theblankets shall be specified on the purchase order. Somes
41、tandard 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.) slottedsize for which the permissible variation shall be 625 mm(61.0 in.).10.2 ThicknessSee Table 5.10.2.1 Manufacturers must m
42、eet 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.TABLE 2 Electrical Proof-TestsClassAC DCProof-Test Voltage,rms,VNominal ElectrodeClearancesA Proof-Test Voltages,
43、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 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 requir
44、ed by a change in atmospheric conditionsfrom the standard of 100 kPa (1 atm) barometric pressure and average humidity conditions. These clearances may be decreased if atmospheric conditions permit.BDC proof-test voltages were determined using negative polarity.TABLE 3 Physical RequirementsType I Typ
45、e IIStyle ABlanketStyle BBlanketStyle ABlanketTensile strength, min, Die C,MPa (psi)17.2 (2500) 17.2 (2500) 10.3 (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 (l
46、bf/in.)18 (100) 26 (150) 18 (100)Drape stiffness, max at25C (77F), mm (in.)89 (3.5) 89 (3.5) 89 (3.5)Drape stiffness, 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.
47、034 (0.30) 0.034 (0.30) 0.034 (0.30)Moisture absorption, max, % 1.5 3.0 2.0TABLE 4 Standard Blanket SizesLength 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
48、560 (22 by 22)910 by 910 (36 by 36)1160 by 1160 (45.5 by 45.5)D 1048 05310.3 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.) high.10.4 EyeletsIf other than manufacturers standard is de-sired; the number, size, and type of eyelet shall be given on thep
49、urchase 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 physical irregu-larities, which can be detected by thorough test or inspection.11.1.1 Harmful physical irregularities may be defined as anyfeature that disrupts the uniform, smooth surface and repre-sents a potential hazard to the user, such as
