1、Designation: F478 09Standard Specification forIn-Service Care of Insulating Line Hose and Covers1This standard is issued under the fixed designation F478; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last revision. A
2、 number in parentheses indicates the year of last reapproval. A superscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers the in-service care, inspection,testing, and use voltage of insulating line hose and covers forprotection of
3、 workers from accidental contact with energizedelectrical wires or equipment.1.2 The following safety hazards caveat applies only to thetest method portion, Section 7, of this specification: Thisstandard does not purport to address all of the safety problems,if any, associated with its use. It is th
4、e responsibility of the userof this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions prior to use. Specific precautionary statements are givenin 7.2.1.2. Referenced Documents2.1 ASTM Standards:2D1049 Specification for Rubber Insu
5、lating CoversD1050 Specification for Rubber Insulating Line HoseD2865 Practice for Calibration of Standards and Equipmentfor Electrical Insulating Materials TestingF819 Terminology Relating to Electrical Protective Equip-ment for Workers2.2 ANSI Standards:C 84.1 Voltage Ratings for Electric Power Sy
6、stems andEquipment (60 Hz)3C 39.5 Safety Requirements for Electrical and ElectronicMeasuring and Controlling Instrumentation32.3 IEEE Standard:IEEE Standard 4 Techniques for High Voltage Testing43. Terminology3.1 breakdownthe electrical discharge or arc occurringbetween the electrodes and through th
7、e equipment being tested.3.2 bulk storage the storage of hose or covers togetherwith one or more layers piled neatly, but without the benefit ofspacers, supports, or special protective containers.3.3 coveran electrically insulated enclosure designed tobe installed temporarily on various types of irr
8、egularly shapedelectrical equipment to protect personnel and equipment work-ing in the close proximity.3.4 designated personan individual who is qualified byexperience or training to perform an assigned task.3.5 distortedphysically changed from the natural andoriginal shape, caused by stress of any
9、type.3.6 electrical testing facilitya location with qualified per-sonnel, testing equipment, and procedures for the inspectionand electrical testing of electrical insulating protective equip-ment.3.7 electrodethe energized or grounded conductor portionof electrical test equipment which is placed nea
10、r or in contactwith the material or equipment being tested.3.8 flashoverthe electrical discharge or arc occurringbetween electrodes and over or around, but not through, theequipment being tested.3.9 hosean electrical insulating tube with a longitudinalslit designed to be installed temporarily on ene
11、rgized electricalwires.3.10 ozonea very active form of oxygen that may beproduced by corona, arcing, or ultraviolet rays.3.11 ozone cutting and checkingcracks produced byozone in a material under mechanical stress.3.12 retestthe tests given after the initial acceptance test,usually performed at regu
12、lar periodic intervals or as requiredbecause of physical inspection.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.Current edition approved Oct.
13、1, 2009. Published November 2009. Originallyapproved in 1976. Last previous edition approved in 2007 as F478 92(2007). DOI:10.1520/F0478-09.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volum
14、e information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.4Available from Institute of Electrical and Electronics Engineers, Inc., 445 HoesLane, Piscata
15、way, NJ 08854-4150.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.13 voltage, maximum retestvoltage, either ac rms or dcaverage, that is equal to the proof test voltage for newprotective equipment.3.14 voltage, nominal designa nom
16、inal value consistentwith the latest revision of ANSI C 84.1, assigned to the circuitor system for the purpose of conveniently designating itsvoltage class.3.15 voltage, retest voltage, either ac rms or dc average,that used protective equipment must be capable of withstand-ing for a specific test pe
17、riod without breakdown.3.16 For definitions of other terms, refer to TerminologyF819.4. Significance and Use4.1 Compliance with this specification should continue toprovide personnel with insulating line hose and covers ofknown and acceptable quality after initial acceptance in accor-dance with Spec
18、ifications D1050 and D1049. The standardsherein are to be considered as minimum requirements.4.2 A margin of safety shall be provided between themaximum use voltage and their class proof voltage in accor-dance with Specifications D1050 and D1049, as shown inTable 1.4.3 The user of this type of prote
19、ctive equipment shall beknowledgeable of and instructed in the correct and safeinspection and use of this equipment.5. Classification5.1 Line hose covered in this specification are designed asType I or Type II; Class 0, Class 1, Class 2, Class 3 or Class 4;Style A, Style B, Style C or Style D. Cover
20、s covered in thisstandard are designated as Type I or Type II; Class 0, Class 1,Class 2, Class 3 or Class 4; Style A, Style B, Style C, Style Dor Style E.5.1.1 Type IHigh-grade cis-1,4-polyisoprene rubber com-pound of natural or synthetic origin, properly vulcanized.5.1.2 Type IIOzone resistant, mad
21、e of any elastomer orcombination of elastomeric compounds.5.1.3 The class designations are based on the electricalproperties in Specifications D1050 and D1049.5.1.4 The style designations are based on the designs anddescriptions in Specifications D1050 and D1049.6. Washing and Inspection6.1 The reco
22、mmended sequence of washing and inspectionof contaminated insulating line hose and covers is as follows:6.1.1 Washing,6.1.2 Drying,6.1.3 Inspection,6.1.4 Marking, and6.1.5 Packing for storage and shipment.6.2 The hose and covers may be washed with a soap, mildnon-bleaching detergent, or a cleaner re
23、commended by theequipment manufacturer. After washing, the hose and coversshall be rinsed thoroughly with water.6.2.1 The cleaning agent shall not degrade the insulatingqualities of the line hose and covers.6.2.2 A commercial tumble-type washing machine may beused, where practicable, but caution mus
24、t be observed toeliminate any interior surfaces or edges that will cut, abrade,puncture, or pinch the hose or covers.6.3 The hose and covers shall be air dried. The air tempera-ture shall not be over 150F (65.5C). They may be suspendedto allow drainage and air circulation or dried in a commercialtum
25、ble-type automatic dryer. In an automatic dryer, cautionmust be observed to eliminate any ozone-producing lamps andinterior surfaces that will cut, abrade, puncture, or pinch thehose and covers.6.4 Insulating line hose and covers shall be given a detailedinspection over the entire inner and outer su
26、rface for punctures,cuts, severe ozone cutting, or any other obvious condition thatwould adversely affect performance.6.5 The hose and covers shall be marked in accordance withSection 12.7. Electrical Tests7.1 Where the inspection specified in Section 6 indicatesthat there may be reason to suspect t
27、he electrical integrity of aline hose or cover, an electrical test shall be performed beforereissuing the line hose or cover for service.7.2 Both ac and dc voltage retest methods are included inthis section and either or both methods may be selected forelectrical test.7.2.1 WarningIn addition to oth
28、er precautions, it isrecommended that the test apparatus be designed to afford theoperator full protection in the performance of duties. Reliablemeans of de-energizing and grounding the high-voltage circuitshould be provided. It is particularly important to incorporatepositive means of grounding the
29、 high-voltage section of dc testapparatus due to the likely presence of high-voltage capaci-tance charges at the conclusion of the test. See ANSI C 39.5.7.2.2 To eliminate damaging ozone and possible flashoveralong the line hose and cover openings, there should be asufficient flow of air into and ar
30、ound the line hose or cover andan exhaust system to adequately remove ozone from the testmachine. Consistent ozone cutting and checking during the testprocedure should be cause to ascertain the adequacy of theexhaust system.7.3 Any electrical retest shall be performed at normal roomtemperatures and
31、on clean hose or covers at an electrical testingfacility.7.4 Electrodes:7.4.1 The entire area of each hose and cover shall be tested,as nearly as practicable, between electrodes that apply theelectrical stress uniformly over the test area without producingdamaging corona or mechanical strain in the
32、hose or cover. TheTABLE 1 Voltage Requirements Line Hose and CoversClassDesignation ofHose andCoversAC UseVoltage, rms,maxDC MaxUse Voltageavg, VAC RetestVoltage, rmsDC RetestVoltage, avg0 1000 1500 5000 20 0001 7500 11250 10 000 40 0002 17 000 25500 20 000 50 0003 26 500 39750 30 000 60 0004 36 000
33、 54000 40 000 70 000F478 092electrodes shall be of such dimensions and so placed as toavoid flashover at the edges.7.4.2 For hose, the inside electrode shall be a metal mandrelof the size in Table 2. The outer electrode should be aclose-fitting wet sponge or wet fabric blanket, metal foil, or asmoot
34、h metal form; extending to within12 in. (13 mm) of theedge of the lip of the hose, and extending to a distance from theend of the hose as specified in Table 3. If the hose has aconnector end, the form should extend to within12 in. (13 mm)of the connector end. When Style C line hose is tested, theout
35、er electrode may fit around the outside diameter of the hose,but not the extended lip (Note 1).NOTE 1These end clearances are intended to serve as a guide andunder some conditions may have to be increased to prevent flashover.7.4.3 For covers, the electrodes shall be one of thosedescribed in the fol
36、lowing methods:7.4.3.1 Method 1 for Types I and IIWater as inner andouter electrodes.7.4.3.2 Method 2 for Types I and IIWet sponge or wet feltinner electrode; and wet sponge, wet felt, or metal foil outerelectrode.7.4.3.3 Method 3 for Type IIFixed form metal or metalfoil inner or outer electrodes, o
37、r both.NOTE 2Method 3 electrodes shall not be used with Type I materialswhen testing with alternating current due to the possibility of coronacutting.7.5 AC Test:7.5.1 Voltage Supply and RegulationThe voltage supplyand control equipment should be of such size and design that,with the test specimens
38、in the circuit, the crest factor (ratio ofpeak to mean effective) of the test voltage shall differ by notmore than 5 % from that of a sinusoidal wave over the upperhalf of the range of the test voltage. The correct rms value ofthe sinusoidal voltage waveform applied to the hose or covermay be measur
39、ed by one of the following methods:7.5.1.1 A voltmeter used in conjunction with a calibratedinstrument transformer connected directly across the highvoltage circuit,7.5.1.2 A calibrated electrostatic voltmeter connected di-rectly across the high voltage circuit,7.5.1.3 An ac meter connected in serie
40、s with appropriatehigh voltage type resistors directly across the high voltagecircuit.7.5.1.4 The equipment shall be inspected at least annually toensure that the general condition of the equipment is acceptableand to verify the characteristics and accuracy of the testvotlages. The accuracy of the v
41、oltage measuring circuit shall be62 % of full scale. To ensure the continued accuracy of the testvoltage, as indicated by the test equipment voltmeter, the testequipment shall be calibrated at least annually in accordancewith the latest revision of Practice D2865 or IEEE Standard 4.The crest factor
42、may be checked by the use of a peak readingvoltmeter connected directly across the high-voltage circuit.7.5.2 AC RetestElectrical retest of a hose or cover shall bein accordance with the requirements of Section 8.NOTE 3It is recommended that the retest voltage be applied initiallyat a low value and
43、increased gradually at a constant rate-of-rise ofapproximately 1000 V/s ac until the prescribed test voltage level isreached. Unless an electrical puncture has occurred already, the appliedvoltage should be reduced to at least half value at the end of the test periodbefore opening the test circuit.7
44、.6 DC Test:7.6.1 Voltage Supply and Regulation:7.6.1.1 The dc test voltage can be obtained from a sourcecapable of supplying a dc voltage whose peak-to-peak ac ripplecomponent does not exceed 2 % of the average voltage valueunder no-load conditions.7.6.1.2 The dc test voltage shall be measured by a
45、methodthat provides the average value of the voltage applied to thehose or cover. It is recommended that the voltage be measuredby the use of a dc meter connected in series with appropriatehigh-voltage type resistors across the high-voltage circuit, orby an electrostatic voltmeter of proper range. T
46、he accuracy ofthe voltage measuring circuit shall be within 62 % of fullscale. The test equipment shall be calibrated at least annually,in accordance with the latest revision of Practice D2865 or thelatest revision of IEEE Standard 4.7.6.2 DC RetestElectrical retest of a hose or cover shallbe in acc
47、ordance with the requirements of Section 8.NOTE 4It is recommended the dc retest voltage should be applied inthe same manner as for ac retest voltage, with the exception of arate-of-rise of approximately 3000 V/s.8. Rejection Criteria8.1 Any hose or cover that fails to comply with the electricalrete
48、st requirements as indicated in this section shall be rejected.8.2 Each hose or cover tested, as required by 7.1, shallwithstand the 60-Hz ac retest voltage (rms value) or the dcretest voltage (average value) specified in Table 1. The testvoltage shall be applied continuously for not less than 1 min
49、and not more than 3 min.TABLE 2 Line Hose Test Mandrel SizeHose Size, Inside Diameter, in.(mm)Recommended Test Mandrel Size,Outside Diameter, in. (mm)14 (6.4)316 (4.8)58 (16)916 (14.3)1 (25)1516 (23.8)114 (32) 1316 (30)112 (38) 114 (31.8)2 (51) 134 (44.4)212 (63.5) 214 (57.2)TABLE 3 Flashover Clearances Between ElectrodesAClass Desig-nation,Line Hoseor CoverAC Retest DC Retestin.mmin.m03763761 3 76 4 1022 5 127 6 1523 7 178 8 2034 10 254 12 305AFlashover clearances are stated in terms of the shortest electrical air pathbetween electrodes
