1、Designation: F 478 92 (Reapproved 2007)Standard Specification forIn-Service Care of Insulating Line Hose and Covers1This standard is issued under the fixed designation F 478; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、 of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 co
3、vers forprotection from electrical shock.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 the responsibility of the userof this
4、standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions prior to use. Specific precautionary statements are givenin Note 1.2. Referenced Documents2.1 ASTM Standards:2D 1049 Specification for Rubber Insulating CoversD 1050 Specification
5、for Rubber Insulating Line HoseD 2865 Practice for Calibration of Standards and Equip-ment for Electrical Insulating Materials Testing2.2 ANSI Standards:C 84.1 Voltage Ratings for Electric Power Systems andEquipment (60 Hz)32.3 IEEE Standard:IEEE Standard 4, Techniques for High Voltage Testing43. Te
6、rminology3.1 breakdownthe electrical discharge or arc occurringbetween the electrodes and through the 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
7、coveran electrically insulated enclosure designed tobe installed temporarily on various types of irregularly 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 assign
8、ed task.3.5 distortedphysically changed from the natural andoriginal shape, caused by stress of any 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
9、electrodethe energized or grounded conductor portionof electrical test equipment which is placed near 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 h
10、osean electrical insulating tube with a longitudinalslit designed to be installed temporarily on energized 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 mech
11、anical stress.3.12 retestthe tests given after the initial acceptance test,usually performed at regular periodic intervals or as requiredbecause of physical inspection.3.13 voltage, maximum usethe a-c voltage (rms) classifi-cation of the protective equipment that designates the maxi-mum nominal desi
12、gn voltage of the energized system that maybe safely worked. The nominal design voltage is equal tophase-to-phase voltage on multiphase circuits.3.13.1 If there is no multiphase exposure in a system area,and the voltage exposure is limited to phase (polarity on d-csystems) to ground potential, the p
13、hase (polarity on d-csystems) to ground potential shall be considered to be thenominal design voltage.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 Equipm
14、ent.Current edition approved June 1, 2007. Published July 2007. Originally approvedin 1976. Last previous edition approved in 1999 as F 478 92(1999).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStanda
15、rds volume 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
16、, Piscataway, NJ 08854-4150.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.13.2 If electrical equipment and devices are insulated, orisolated, or both, such that the multiphase exposure on agrounded wye circuit is removed, then th
17、e nominal designvoltage may be considered as the phase-to-ground voltage onthat circuit.3.14 voltage, maximum retestvoltage, either a-c rms ord-c average, that is equal to the proof test voltage for newprotective equipment.3.15 voltage, nominal designa nominal value consistentwith the latest revisio
18、n of ANSI C 84.1, assigned to the circuitor system for the purpose of conveniently designating itsvoltage class.3.16 voltage, retest voltage, either a-c rms or d-c average,that used protective equipment must be capable of withstand-ing for a specific test period without breakdown.4. Significance and
19、 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 Specifications D 1050 and D 1049. The standardsherein are to be considered as minimum requirements.4.2 A mar
20、gin of safety shall be provided between themaximum use voltage and their class proof voltage in accor-dance with Specifications D 1050 and D 1049, as shown inTable 1.4.3 The user of this type of protective equipment shall beknowledgeable of and instructed in the correct and safeinspection and use of
21、 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. Covers covered in thisstandard are designated as Type I or Type II; Class 0, Class 1,Class 2, Class 3 or
22、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, made of any elastomer orcombination of elastomeric compounds.5.1.3 The class designations are based on
23、the electricalproperties in Specifications D 1050 and D 1049.5.1.4 The style designations are based on the designs anddescriptions in Specifications D 1050 and D 1049.6. Washing and Inspection6.1 The recommended sequence of washing and inspectionof contaminated insulating line hose and covers is as
24、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 recommended by theequipment manufacturer. After washing, the hose and coversshall be rinsed thorou
25、ghly 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 must be observed toeliminate any interior surfaces or edges that will cut, abrade,puncture, or pinc
26、h 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 commercialtumble-type automatic dryer. In an automatic dryer, cautionmust be observed to eliminate any ozone-
27、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 surface for punctures,cuts, severe ozone cutting, or any other obvious condition thatwould adverse
28、ly 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 the electrical integrity of aline hose or cover, an electrical test shall be performed beforereis
29、suing the line hose or cover for service.7.2 Both a-c and d-c voltage retest methods are included inthis section and either or both methods may be selected forelectrical test.NOTE 1Precaution: In addition to other precautions, it is recom-mended that the test apparatus be designed to afford the oper
30、ator fullprotection in the performance of duties. Reliable means of de-energizingand grounding the high-voltage circuit should be provided. It is particu-larly important to incorporate positive means of grounding the high-voltage section of d-c test apparatus due to the likely presence ofhigh-voltag
31、e capacitance charges at the conclusion of the test.7.3 Any electrical retest shall be performed at normal roomtemperatures and 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 elect
32、rodes that apply theelectrical stress uniformly over the test area without producingdamaging corona or mechanical strain in the hose or cover. TheTABLE 1 Voltage Requirements Line Hose and CoversClassDesignation ofHose andCoversA-C UseVoltage, rms,maxAA-C RetestVoltage, rmsD-C RetestVoltage, avg0 10
33、00 5000 20 0001 7500 10 000 40 0002 17 000 20 000 50 0003 26 500 30 000 60 0004 36 000 40 000 70 000AThe maximum use voltage is based on the following equations:1. Maximum use voltage = 0.95 a-c and d-c retest voltage 2 000,Classes 1, 2, 3, and 4.2. Maximum use voltage = 0.95 a-c and d-c reset volta
34、ge 30 500,Classes 1, 2, 3, and 4.3. Maximum use voltage 1 0.95 a-c and d-c retest voltage 18 000, Class 0.F 478 92 (2007)2electrodes 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 ou
35、ter electrode should be aclose-fitting wet sponge or wet fabric blanket, metal foil, or asmooth 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 shoul
36、d extend to within12 in. (13 mm)of the connector end. When Style C line hose is tested, theouter electrode may fit around the outside diameter of the hose,but not the extended lip (Note 2).NOTE 2These end clearances are intended to serve as a guide andunder some conditions may have to be increased t
37、o prevent flashover.7.4.3 For covers, the electrodes shall be one of thosedescribed in the following 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 outerel
38、ectrode.7.4.3.3 Method 3 for Type IIFixed form metal or metalfoil inner or outer electrodes, or both.NOTE 3Method 3 electrodes shall not be used with Type I materialswhen testing with alternating current due to the possibility of coronacutting.7.5 A-C Test:7.5.1 Voltage Supply and RegulationThe volt
39、age supplyand control equipment should be of such size and design that,with the test specimens 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. Th
40、e correct rms value ofthe sinusoidal voltage waveform applied to the hose or covermay be measured 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 voltm
41、eter connected di-rectly across the high voltage circuit,7.5.1.3 An a-c meter connected in series with appropriatehigh voltage type resistors directly across the high voltagecircuit.7.5.1.4 The accuracy of the voltage measuring circuit shallbe 62 % of full scale. To ensure the continued accuracy of
42、thetest voltage, as indicated by the test equipment voltmeter, thetest equipment shall be calibrated at least annually in accor-dance with the latest revision of Practice D 2865 or IEEEStandard 4. The crest factor may be checked by the use of apeak reading voltmeter connected directly across the hig
43、h-voltage circuit.7.5.2 A-C RetestElectrical retest of a hose or cover shallbe in accordance with the requirements of Section 8.NOTE 4It is recommended that the retest voltage be applied initiallyat a low value and increased gradually at a constant rate-of-rise ofapproximately 1000 V/s a-c until the
44、 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.7.6 D-C Test:7.6.1 Voltage Supply and Regulation:7.6.1.1 The d-c test voltage can be
45、obtained from a sourcecapable of supplying a d-c voltage whose peak-to-peak a-cripple component does not exceed 2 % of the average voltagevalue under no-load conditions.7.6.1.2 The d-c test voltage shall be measured by a methodthat provides the average value of the voltage applied to thehose or cove
46、r. It is recommended that the voltage be measuredby the use of a d-c meter connected in series with appropriatehigh-voltage type resistors across the high-voltage circuit, orby an electrostatic voltmeter of proper range. The accuracy ofthe voltage measuring circuit shall be within 62 % of fullscale.
47、 The test equipment shall be calibrated at least annually,in accordance with the latest revision of Practice D 2865 or thelatest revision of IEEE Standard 4.7.6.2 D-C RetestElectrical retest of a hose or cover shallbe in accordance with the requirements of Section 8.NOTE 5It is recommended the d-c r
48、etest voltage should be applied inthe same manner as for a-c 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 electricalretest requirements as indicated in this section shall be rejected.8.2 Each ho
49、se or cover shall withstand the 60-Hz a-c retestvoltage (rms value) or the d-c retest voltage (average value)specified in Table 1. The test voltage shall be applied continu-ously for not less than 1 min and not more than 3 min.8.3 Any hose or cover that upon inspection is found to havepunctures, deep cuts, severe corona or ozone cutting, contami-nation from injurious materials, or has lost its normal elasticity,shall be rejected.TABLE 2 Line Hose Test Mandrel SizeHose Size, Inside Diameter, in.(mm)Recommended Test Mandrel Size,Outside Diameter,
