1、Designation: F478 14F478 14aStandard 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 rev
2、ision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon () 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 forprotecti
3、on of workers from accidental contact with energized electrical wires or equipment.1.2 The following safety hazards caveat applies only to the test method portion, Section 7, of this specification:This standarddoes not purport to address all of the safety problems, if any, associated with its use. I
4、t is the responsibility of the user of thisstandard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior touse.Specific precautionary statements are given in 7.2.1.2. Referenced Documents2.1 ASTM Standards:2D1049 Specification for Rubbe
5、r Insulating CoversD1050 Specification for Rubber Insulating Line HoseD2865 Practice for Calibration of Standards and Equipment for Electrical Insulating Materials TestingF819 Terminology Relating to Electrical Protective Equipment for Workers2.2 ANSI Standards:C 84.1 Voltage Ratings for Electric Po
6、wer Systems and Equipment (60 Hz)3C 39.5 Safety Requirements for Electrical and Electronic Measuring and Controlling Instrumentation32.3 IEEE Standard:IEEE Standard 4 Techniques for High Voltage Testing43. Terminology3.1 breakdownthe electrical discharge or arc occurring between the electrodes and t
7、hrough the equipment being tested.3.2 bulk storage the storage of hose or covers together with one or more layers piled neatly, but without the benefit of spacers,supports, or special protective containers.3.3 coveran electrically insulated enclosure designed to be installed temporarily on various t
8、ypes of irregularly shapedelectrical equipment to protect personnel and equipment working in the close proximity.3.4 designated personan individual who is qualified by experience or training to perform an assigned task.3.5 distortedphysically changed from the natural and original shape, caused by st
9、ress of any type.3.6 electrical testing facilitya location with qualified personnel, testing equipment, and procedures for the inspection andelectrical testing of electrical insulating protective equipment.3.7 electrodethe energized or grounded conductor portion of electrical test equipment which is
10、 placed near or in contact withthe material or equipment being tested.3.8 flashoverthe electrical discharge or arc occurring between electrodes and over or around, but not through, the equipmentbeing tested.1 This specification is under the jurisdiction of ASTM Committee F18 on Electrical Protective
11、 Equipment for Workers and is the direct responsibility of SubcommitteeF18.25 on Insulating Cover-Up Equipment.Current edition approved April 1, 2014Nov. 1, 2014. Published April 2014December 2014. Originally approved in 1976. Last previous edition approved in 20092014 asF478 09.F478 14 DOI: 10.1520
12、/F0478-14.10.1520/F0478-14A.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 Available from American Nationa
13、l Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.4 Available from Institute of Electrical and Electronics Engineers, Inc., 445 Hoes Lane, Piscataway, NJ 08854-4150.This document is not an ASTM standard and is intended only to provide the user of an ASTM
14、 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 consult prior editions as appropriate. In all cases only the current versionof the standard as published b
15、y ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.9 hosean electrical insulating tube with a longitudinal slit designed to be installed temporarily on energized electrical wires.3.10 oz
16、onea very active form of oxygen that may be produced by corona, arcing, or ultraviolet rays.3.11 ozone cutting and checking cracks produced by ozone in a material under mechanical stress.3.12 retestthe tests given after the initial acceptance test, usually performed at regular periodic intervals or
17、as required becauseof physical inspection.3.13 voltage, maximum retestvoltage, either ac rms or dc average, that is equal to the proof test voltage for new protectiveequipment.3.14 voltage, nominal designa nominal value consistent with the latest revision of ANSI C84.1, assigned to the circuit orsys
18、tem for the purpose of conveniently designating its voltage class.3.15 voltage, retest voltage, either ac rms or dc average, that used protective equipment must be capable of withstanding fora specific test period without breakdown.3.16 For definitions of other terms, refer to Terminology F819.4. Si
19、gnificance and Use4.1 Compliance with this specification should continue to provide personnel with insulating line hose and covers of known andacceptable quality after initial acceptance in accordance with Specifications D1050 and D1049. The standards herein are to beconsidered as minimum requiremen
20、ts.4.2 A margin of safety shall be provided between the maximum use voltage and their class proof voltage in accordance withSpecifications D1050 and D1049, as shown in Table 1.4.3 The user of this type of protective equipment shall be knowledgeable of and instructed in the correct and safe inspectio
21、nand use of this equipment.5. Classification5.1 Line hose covered in this specification are designed as Type I or Type II; Class 0, Class 1, Class 2, Class 3 or Class 4; StyleA, Style B, Style C or Style D. Covers covered in this standard are designated as Type I or Type II; Class 0, Class 1, Class
22、2, Class3 or Class 4; Style A, Style B, Style C, Style D or Style E.5.1.1 Type IHigh-grade cis-1,4-polyisoprene rubber compound of natural or synthetic origin, properly vulcanized.5.1.2 Type IIOzone resistant, made of any elastomer or combination of elastomeric compounds.5.1.3 The class designations
23、 are based on the electrical properties in Specifications D1050 and D1049.5.1.4 The style designations are based on the designs and descriptions in Specifications D1050 and D1049.6. Washing and Inspection6.1 The recommended sequence of washing and inspection of contaminated insulating line hose and
24、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, mild non-bleaching detergent, or a cleaner recommended by the equipmentmanufacturer. After washing, the hose and covers shall b
25、e rinsed thoroughly with water.6.2.1 The cleaning agent shall not degrade the insulating qualities of the line hose and covers.6.2.2 A commercial tumble-type washing machine may be used, where practicable, but caution must be observed to eliminateany interior surfaces or edges that will cut, abrade,
26、 puncture, or pinch the hose or covers.TABLE 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
27、30 000 60 0004 36 000 54000 40 000 70 000F478 14a26.3 The hose and covers shall be air dried. The air temperature shall not be over 150F (65.5C). They may be suspended toallow drainage and air circulation or dried in a commercial tumble-type automatic dryer. In an automatic dryer, caution must beobs
28、erved to eliminate any ozone-producing lamps and interior surfaces that will cut, abrade, puncture, or pinch the hose and covers.6.4 Insulating line hose and covers shall be given a detailed inspection over the entire inner and outer surface for punctures,cuts, severe ozone cutting, or any other obv
29、ious condition that would adversely affect performance.6.5 The hose and covers shall be marked in accordance with Section 12.7. Electrical Tests7.1 Where the inspection specified in Section 6 indicates that there may be reason to suspect the electrical integrity of a linehose or cover, an electrical
30、 test shall be performed before reissuing the line hose or cover for service.7.2 Both ac and dc voltage retest methods are included in this section and either or both methods may be selected for electricaltest.7.2.1 WarningIn addition to other precautions, it is recommended that the test apparatus b
31、e designed to afford the operatorfull protection in the performance of duties. Reliable means of de-energizing and grounding the high-voltage circuit should beprovided. It is particularly important to incorporate positive means of grounding the high-voltage section of dc test apparatus dueto the lik
32、ely presence of high-voltage capacitance charges at the conclusion of the test. See ANSI C 39.5.7.2.2 To eliminate damaging ozone and possible flashover along the line hose and cover openings, there should be a sufficientflow of air into and around the line hose or cover and an exhaust system to ade
33、quately remove ozone from the test machine.Consistent ozone cutting and checking during the test procedure should be cause to ascertain the adequacy of the exhaust system.7.3 Any electrical retest shall be performed at normal room temperatures and on clean hose or covers at an electrical testingfaci
34、lity.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 the electricalstress uniformly over the test area without producing damaging corona or mechanical strain in the hose or cover. The electrodesshall be of such dime
35、nsions and so placed as to avoid flashover at the edges.7.4.2 For hose, the inside electrode shall be a metal mandrel of the size in Table 2. The outer electrode should be a close-fittingwet sponge or wet fabric blanket, metal foil, or a smooth metal form; extending to within 12 in. (13 mm) of the e
36、dge of the lipof the hose, and extending to a distance from the end of the hose as specified in Table 3. If the hose has a connector end, the formshould extend to within 12 in. (13 mm) of the connector end. When Style C line hose is tested, the outer electrode may fit aroundthe outside diameter of t
37、he hose, but not the extended lip (Note 1).NOTE 1These end clearances are intended to serve as a guide and under some conditions may have to be increased to prevent flashover.7.4.3 For covers, the electrodes shall be one of those described in the following methods:7.4.3.1 Method 1 for Types I and II
38、Water as inner and outer electrodes.7.4.3.2 Method 2 for Types I and IIWet sponge or wet felt inner electrode; and wet sponge, wet felt, or metal foil outerelectrode.7.4.3.3 Method 3 for Type IIFixed form metal or metal foil inner or outer electrodes, or both.NOTE 2Method 3 electrodes shall not be u
39、sed with Type I materials when testing with alternating current due to the possibility of corona cutting.7.5 AC Test:7.5.1 Voltage Supply and Regulation:7.5.1.1 The voltage supply and control equipment should be of such size and design that, with the test specimens in the circuit,the crest factor (r
40、atio of peak to mean effective) of the test voltage shall differ by not more than 5 % from that of a sinusoidal waveover the upper half of the range of the test voltage.7.5.1.2 The accuracy of the voltage measuring circuit shall be within 61 kV of the test voltage. The ac voltage applied to thetest
41、specimen shall be measured with either a RMS responding voltmeter or an ac voltmeter (RMS or average responding) or apeak responding voltmeter calibrated to pk/SQRT2 using one of the following methods: (1) a voltmeter used in conjunction withTABLE 2 Line Hose Test Mandrel SizeHose Size, Inside Diame
42、ter, 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)F478 14a3a calibrated instrument transformer connected directly across the high-voltage circuit, (2) a
43、calibrated electrostatic voltmeterconnected directly across the high-voltage circuit, or (3) an ac voltmeter connected in series with appropriate high voltage typeresistors directly across the high-voltage circuit. To ensure the continued accuracy of the test voltage, as indicated by the testequipme
44、nt voltmeter, the test equipment shall be calibrated at least annually in accordance with the latest revision of PracticeD2865 or IEEE Standard 4.7.5.1.3 The crest factor may be checked by the use of a peak reading voltmeter connected directly across the high-voltage circuitor, if an electrostatic v
45、oltmeter or a voltmeter in conjunction with an instrument potential transformer is connected across thehigh-voltage circuit, a standard sphere gap may be sparked over and the corresponding voltage compared with the reading of therms voltmeter.7.5.2 AC RetestElectrical retest of a hose or cover shall
46、 be in accordance with the requirements of Section 8.NOTE 3It is recommended that the retest voltage be applied initially at a low value and increased gradually at a constant rate-of-rise of approximately1000 V/s ac until the prescribed test voltage level is reached. Unless an electrical puncture ha
47、s occurred already, the applied voltage should be reducedto at least half value at the end of the test period before opening the test circuit.7.6 DC Test:7.6.1 Voltage Supply and Regulation:7.6.1.1 The dc test voltage can be obtained from a source capable of supplying a dc voltage whose peak-to-peak
48、 ac ripplecomponent does not exceed 2 % of the average voltage value under no-load conditions.7.6.1.2 The dc test voltage shall be measured by a method that provides the average value of the voltage applied to the testspecimen. It is recommended that the voltage be measured by the use of a dc meter
49、connected in series with appropriatehigh-voltage type resistors across the high-voltage circuit, or by an electrostatic voltmeter of proper range. The accuracy of thevoltage measuring circuit shall be within 61 kV of the test voltage . The test equipment shall be calibrated at least annually, inaccordance with the latest revision of Practice D2865 or the latest revision of IEEE Standard 4.7.6.2 DC RetestElectrical retest of a hose or cover shall be in accordance with the requirements of Section 8.NOTE 4It is recommended the dc retest
