1、Designation:F 968 93(Reapproved 2002)e1Standard Specification forElectrically Insulating Plastic Guard Equipment forProtection of Workers1This standard is issued under the fixed designation F 968;the number immediately following the designation indicates the year oforiginal adoption or,in the case o
2、f revision,the year 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.e1NOTEA precision and bias statement was added in May 2004.1.Scope1.1 This specification covers plastic guard
3、equipment andguard systems used by workers for temporary insulation onelectric power circuits.1.2 Plastic guard equipment covered by this specification israted for momentary,or brush contact only.Maximum-usevoltages are covered in Annex A1.1.3 Typical guards covered include,but are not limited to,th
4、e following:1.3.1 Conductor guards and connecting covers as follows:1.3.1.1 Line guards,1.3.1.2 Line guard connectors,1.3.1.3 Insulator covers,1.3.1.4 Dead end covers,1.3.1.5 Bus guards,and1.3.1.6 Bus“T”guards.1.3.2 Structure and apparatus covers as follows:1.3.2.1 Pole guards,1.3.2.2 Ridge pin cove
5、rs,1.3.2.3 Switch-blade covers,1.3.2.4 Arm guards,1.3.2.5 Cutout covers,and1.3.2.6 Cross arm guard.1.4 The values stated in inch-pound units are to be regardedas the standard.2.Referenced Documents2.1 ASTM Standards:D 149 Test Methods for Dielectric Breakdown Voltage andDielectric Strength of Solid
6、Electrical Insulating Materialsat Commercial Power Frequencies2D 150 Test Methods for AC Loss Characteristics and Per-mittivity(Dielectric Constant)of Solid Electrical Insulat-ing Materials2D 256 Test Methods for Determining the Pendulum ImpactResistance of Notched Specimens of Plastics3D 570 Test M
7、ethod for Water Absorption of Plastics3F 712 Test Methods for Electrically Insulating PlasticGuard Equipment for Protection of Workers42.2IEEE Standard:978 Guide for In-Service Maintenance and Electrical Test-ing for Live-Line Tools52.3UL Standard:94 Tests for Flammability of Plastic Materials for P
8、arts inDevices and Appliances63.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 insulating plastic guardsdevices for temporary in-stallation on structures or energized electric power circuits forelectrical protection of personnel or equipment,or both.3.1.2 self extinguishingrelat
9、es to a property of a plasticmaterial compounded so as to cease combustion on removal ofthe source that caused ignition.4.Significance and Use4.1 This specification covers the minimum electrical,chemical,and physical properties designated by the manufac-turer and the detailed procedures by which suc
10、h properties areto be determined.The purchaser has the option to perform orhave performed any of these tests and may reject equipmentthat fails to meet the standard criteria.Claims concerningfailure to meet the specification are subject to verification bythe manufacturer.4.2 Plastic guard equipment
11、is used for protection againstaccidental brush contact by the worker.Amargin of safety shallbe provided between the maximum voltage at which they areused and the proof-test voltage at which they are tested.This1This specification is under the jurisdiction of ASTM Committee F18 onElectrical Protectiv
12、e Equipment for Workers and is the direct responsibility ofSubcommittee F18.25 on Insulating Cover-up Equipment.Current edition approved Jan.15,1993.Published March 1993.Originallypublished as F 968 85.Last previous edition D 968 90.2Annual Book of ASTM Standards,Vol 10.01.3Annual Book of ASTM Stand
13、ards,Vol 08.01.4Annual Book of ASTM Standards,Vol 10.03.5Available from the Institute of Electrical and Electronics Engineers,345 E.47thSt.,New York,NY 10017.6Available from Underwriters Laboratories,333 Pfingsten Rd.,Northbrook,IL60062.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700
14、,West Conshohocken,PA 19428-2959,United States.relationship is shown in TableA1.1.The equipment is designedonly for phase-to-ground or coveredphase-to-covered-phaseexposure.NOTE1Rubber insulating equipment is realistically limited to Class 4material in the design specification standards.Plastic guar
15、d equipment hasbeen designed to go beyond these voltages and provide a satisfactorydegree of worker protection.Major differences exist in use criteriabetween the rubber and the plastic guard equipment.Each glove,sleeve,or other article of rubber insulating equipment has a given safety factor forthe
16、phase to phase voltage on which it may be used and the class or proofvoltage at which it is tested.Plastic guard equipment,however,is designedto provide a satisfactory safety factor only when used in a phase-to-groundexposure.If exposure is phase-to-phase,then a satisfactory safety factor isonly provided if the exposure is covered-phase-to-covered-phase.4.3 Work practices vary from user to user,dependent uponmany factors.These may include,but are not limited to,operating system voltages,construc
