1、Designation: D1048 12D1048 14Standard 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 par
2、entheses 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 U.S. Department of Defense.1. Scope1.1 This specification covers acceptance testing of rubber insulat
3、ing blankets for protection of workers from accidental contactwith live electrical conductors, apparatus, or circuits.1.2 Two types of blankets are provided and are designated as Type I, not resistant to ozone, and Type II, resistant to ozone.1.3 Five classes of blankets, differing in electrical cha
4、racteristics, 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 characteristics, are provided and are designated as Style A and Style B.1.5 The following safety hazards caveat pertains only to the test method porti
5、on, Sections 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 health practices and determine the applicability of regulatory limi
6、tations priorto use.2. Referenced Documents2.1 ASTM Standards:2D149 Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials atCommercial Power FrequenciesD297 Test Methods for Rubber ProductsChemical AnalysisD412 Test Methods for Vulcanized Rubbe
7、r and Thermoplastic ElastomersTensionD518 Test Method for Rubber DeteriorationSurface Cracking (Withdrawn 2007)3D570 Test Method for Water Absorption of PlasticsD573 Test Method for RubberDeterioration in an Air OvenD624 Test Method for Tear Strength of Conventional Vulcanized Rubber and Thermoplast
8、ic ElastomersD1388 Test Method for Stiffness of FabricsD2865 Practice for Calibration of Standards and Equipment for Electrical Insulating Materials TestingF819 Terminology Relating to Electrical Protective Equipment for Workers2.2 American National Standards:ANSI/IEEE C 2 National Electrical Safety
9、 Code4C84.1 Electric Power Systems and EquipmentVoltage Ratings (60 Hz)53. Terminology3.1 beaded edge a narrow border of thicker rubber which extends completely around the outer edges of the blanket.3.2 breakdownthe electrical discharge or arc occurring between the electrodes and through the equipme
10、nt being tested.3.3 designated personan individual who is qualified by experience or training to perform an assigned task.1 This specification is under the jurisdiction of ASTM Committee F18 on Electrical Protective Equipment for Workers and is the direct responsibility of SubcommitteeF18.25 on Insu
11、lating Cover-Up Equipment. This standard replaces ANSI Standard J 6.4, which is no longer available.Current edition approved Oct. 1, 2012Nov. 1, 2014. Published October 2012December 2014. Originally approved in 1949 as D1048 49 T. Last previous edition approvedin 20112012 as D1048-11.-12. DOI: 10.15
12、20/D1048-12.10.1520/D1048-14.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved version of t
13、his historical standard is referenced on www.astm.org.4 Available from Institute of Electrical and Electronics Engineers, Inc. (IEEE), 445 Hoes Ln., P.O. Box 1331, Piscataway, NJ 08854-1331, http:/www.ieee.org.5 Available from National Electrical Manufacturers Association, 1300 North 17th Street, Ro
14、sslyn, VA 22209.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users c
15、onsult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.4 electrical testing facilitya
16、 location with qualified personnel, testing equipment, and procedures for the inspection andelectrical testing of electrical insulating protective equipment.3.5 electrode clearancethe shortest path from the energized electrode to the ground electrode.3.6 flashoverthe electrical discharge or arc occu
17、rring between electrodes and over or around, but not through, the equipmentbeing tested.3.7 insulatedseparated from other conducting surfaces by a dielectric substance (including air space) offering a high resistanceto the passage of current.3.7.1 DiscussionWhen any object is said to be insulated, i
18、t is understood to be insulated in a suitable manner for the conditionsto which it is subjected. Otherwise, it is, within the purpose of this definition, uninsulated. Insulating covering of conductors is onemeans of making this conductor insulated.3.8 ozonea very active form of oxygen that may be pr
19、oduced by corona, arcing, or ultra-violet rays.3.9 ozone cutting and checking cracks produced by ozone in a material under mechanical stress.3.10 rubbera generic term that includes elastomers and elastomer compounds regardless of origin.3.11 userthe employer or entity purchasing the equipment to be
20、utilized by workers for their protection; in the absence of suchan employer or entity, the individual purchasing or utilizing the protective equipment.3.12 voltage, maximum retestvoltage, either ac rms or dc avg, that is equal to the proof-test voltage for new protectiveequipment.3.13 voltage, retes
21、tvoltage, either ac rms or dc avg, that used protective equipment must be capable of withstanding for aspecified test period without breakdown.3.14 voltage, nominal designa nominal value consistent with the latest revision of ANSI C84.1, assigned to the circuit orsystem for the purpose of convenient
22、ly designating its voltage class.3.15 voltage, maximum usethe ac voltage, (rms), classification of the protective equipment that designates the maximumnominal design voltage of the energized system that may be safely worked. The nominal design voltage is equal to phase-to-phasevoltage on multiphase
23、circuits.3.15.1 If there is no multiphase exposure in a system area, and the voltage exposure is limited to phase (polarity on dc systems)to ground potential, the phase (polarity on dc systems) to ground potential shall be considered to be the nominal design voltage.3.15.2 If electrical equipment an
24、d devices are insulated or isolated, or both, such that the multiphase exposure on a groundedwye circuit is removed, then the nominal design voltage may be considered as the phase-to-ground voltage on that circuit.NOTE 1The work practices and methods associated with removing multiphase exposures at
25、any given work site are not addressed in this specification.Users should refer to ANSI C2, National Electrical Safety Code, Section 44, for proper work practices.3.16 For definitions of other terms, refer to Terminology F819.4. Significance and Use4.1 This specification covers the minimum electrical
26、, chemical, and physical properties guaranteed by the manufacturer and thedetailed procedures by which such properties are to be determined. The purchaser may, at his option, perform or have performedany of these tests in order to verify the guarantee. Claims for failure to meet the specification ar
27、e subject to verification by themanufacturer.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 the proof-test voltage at which they are tested. The relationship betweenproof
28、-test voltage and the nominal maximum voltage at which blankets shall be used is shown in Table 1.TABLE 1 Proof-Test/Use Voltage RelationshipClass of Insu-lating BlanketsNominal MaximumUse Voltage APhase-Phase, ac,rms, maxAC Proof-TestVoltage, rms VDC Proof-TestVoltage, avg, V0 1 000 5 000 20 0001 7
29、 500 10 000 40 0002 17 000 20 000 50 0003 26 500 30 000 60 0004 36 000 40 000 70 000A Except 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 2000D1048 1424.3 Work practices vary from user t
30、o user depending upon many factors. These factors may include, but are not limited to,operating system voltages, construction design, work procedures and techniques, weather conditions, etc. Therefore, except for therestrictions set forth in this specification because of design limitations, the use
31、and maintenance of this equipment is beyond thescope of this specification.4.3.1 It is common practice and the responsibility of the user of this type of protective equipment to prepare completeinstructions and regulations to govern the correct and safe use of such equipment.5. Classification5.1 Bla
32、nkets covered under this specification shall be designated as Type I or Type II; Class 0, Class 1, Class 2, Class 3, or Class4; Style A or Style B.5.1.1 Type I, non-resistant to ozone, made from a high-grade cis-1,4-polyisoprene rubber compound of natural or syntheticorigin, properly vulcanized.5.1.
33、2 Type II, ozone resistant, made of any elastomer or combination of elastomeric compounds.5.1.3 The class designation shall be based on the electrical properties as shown in Table 1 and Table 2.5.1.4 Style A, constructed of the elastomers indicated under Type I or Type II, shall be free of any reinf
34、orcement.5.1.5 Style B, constructed of the elastomers indicated under Type I or Type II, shall incorporate a reinforcement; thisreinforcement shall not adversely affect the dielectric characteristics of the blankets.6. Ordering Information6.1 Orders for blankets under this specification should inclu
35、de 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 is not intended to mean that all shall necessarily be available frommanufacturers; it signifies only that, if made, they shall confor
36、m to the details of this specification.7. Manufacture and Marking7.1 The blankets shall be produced by a seamless vulcanizing process.7.2 Where eyelets are specified, each blanket shall be equipped with nonmetallic eyelets.7.3 Each blanket shall be marked clearly and permanently with the name of the
37、 manufacturer or supplier, ASTM D1048, type,class, and style.7.3.1 Blankets may be marked by either molding the information directly into the blanket or by use of a label; either methodis equally acceptable. The method shall be at the discretion of the manufacturer. If a label is used the color shal
38、l be that specifiedfor each voltage class; Class 0red, Class 1white, Class 2yellow, Class 3green, and Class 4orange.7.4 Blankets shall have a smooth, flat finish and beaded edges.8. Chemical and Physical Requirements8.1 The blanket material shall conform to the physical requirements in Table 3 and t
39、he accelerated aging in 19.2.7.8.2 For Type I blankets, the rubber polymer may be determined in accordance with 19.1.1. This shall be the referee test if adispute exists between the manufacturer and purchaser regarding the elastomer content of Type I blankets.TABLE 2 Electrical Proof-TestsClassAC DC
40、Proof-Test Voltage,rms,VNominal ElectrodeClearances A Proof-Test Voltages, Bavg, VNominal ElectrodeClearances Amm 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 12A These nominal clearances are intended to a
41、void 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 humidity conditions. These clearances may be decreased if atmospheric conditions permit.B DC proof-test voltages w
42、ere determined using negative polarity.D1048 1438.3 The Type II blanket material shall show no visible effects from ozone when tested in accordance with 18.6.Any visible signsof ozone deterioration, such as checking, cracking, breaks, pitting, etc., shall be considered as evidence of failure to meet
43、 therequirements of Type II blankets. In case of dispute, Method A of the ozone resistance test shall be the referee test.9. Electrical Requirements9.1 Each blanket shall be given a proof test and shall withstand the 60-Hz ac proof-test voltage (rms value) or the dc proof-testvoltage (average value)
44、 specified in Table 2. The proof test shall be performed in accordance with Section 18 and shall beconducted continuously for at least 3 min.9.2 The blanket material shall show a 60-Hz dielectric strength of not less than 14.8 MV/m (375 V-rms/mil) of specimenthickness for each individual test, when
45、tested in accordance with 18.5.10. Dimensions and Permissible Variations10.1 Length and Width The length and width of the blankets shall be specified on the purchase order. Some standard sizesare as shown in Table 4. Permissible variations from the specified length and width shall be 613 mm (60.5 in
46、.) except for the1160 by 1160-mm (45.5 by 45.5-in.) slotted size for which the permissible variation shall be 625 mm (61.0 in.).10.2 ThicknessSee Table 5.10.2.1 Manufacturers must meet the minimum thickness requirements for each Class of blanket as specified in Table 5. Themanufacturer may label a b
47、lanket lower than actual Class value 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.) high.10.4 EyeletsIf other than manufacturers standard is desired; the number, size, and type of eyelet shall be given on thepur
48、chase order. The eyelets shall not be less than 8 mm (0.31 in.) in diameter.10.5 No eyelets, holes, or slots are permitted in a blanket which will reduce the test electrode clearance to less than the valueslisted in Table 2.11. Workmanship and Finish11.1 The blankets shall be free of harmful physica
49、l irregularities, which can be detected by thorough test or inspection.TABLE 3 Physical RequirementsType I Type 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 (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 stiffness, max at10C (14F)
