1、Designation: F712 06 (Reapproved 2011)Standard Test Methods and Specifications forElectrically Insulating Plastic Guard Equipment forProtection of Workers1This standard is issued under the fixed designation F712; the number immediately following the designation indicates the year of originaladoption
2、 or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 These test methods cover three electrical tests on plasticguards and assembled g
3、uard systems. They are:1.1.1 Method AWithstand voltage proof test,1.1.2 Method BFlashover voltage, and1.1.3 Method CLeakage current.1.1.4 This specification covers plastic guard equipment andguard systems used by workers for temporary insulation onelectric power circuits.1.1.5 Plastic guard equipmen
4、t covered by this specificationis rated for momentary, or brush contact only. Maximum-usevoltages are covered in Table 1 and Table 2.1.2 These test methods cover, but are not limited to, thefollowing typical guards:1.2.1 Conductor Guards and Connecting Covers as follows:1.2.1.1 Line guards,1.2.1.2 L
5、ine guard connectors,1.2.1.3 Insulator covers,1.2.1.4 Dead-end covers,1.2.1.5 Bus guards, and1.2.1.6 Bus “T” guards.1.2.2 Structure and Apparatus Covers as follows:1.2.2.1 Pole guards,1.2.2.2 Ridge pin covers,1.2.2.3 Switch blade covers,1.2.2.4 Arm guards,1.2.2.5 Cutout covers,1.2.2.6 Structural bar
6、riers, and1.2.2.7 Cross arm guard.1.3 It is common practice for the user of this equipment toprepare instructions for the correct use and maintenance.1.4 The use and maintenance of this equipment is beyondthe scope of these test methods.1.5 This standard does not purport to address all of thesafety
7、concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.6 The values stated in inch-pound units are to be regardedas standard. The v
8、alues given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.2. Referenced Documents2.1 ASTM Standards:2D149 Test Method for Dielectric Breakdown Voltage andDielectric Strength of Solid Electrical Insulating Materialsat Comm
9、ercial Power FrequenciesD256 Test Methods for Determining the Izod PendulumImpact Resistance of PlasticsD570 Test Method for Water Absorption of Plastics2.2 IEEE Standard:3IEEE 978 Guide for In-Service Maintenance and ElectricalTesting for Live-Line Tools2.3 ANSI Standard:4C39.5 Safety Requirements
10、for Electrical and ElectronicMeasuring and Controlling Instrumentation2.4 UL Standard:594 Tests for Flammability of Plastic Materials for Parts inDevices and Appliances3. Terminology3.1 Definitions of Terms Specific to This Standard:1These test methods are under the jurisdiction of ASTM Committee F1
11、8 onElectrical Protective Equipment for Workers and are the direct responsibility ofSubcommittee F18.25 on Insulating Cover-Up Equipment.Current edition approved Nov. 15, 2011. Published November 2011. Originallyapproved in 1981. Last previous edition approved in 2006 as F712 06. DOI:10.1520/F0712-0
12、6R11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Institute of Electrical and Electronics
13、Engineers, Inc. (IEEE),445 Hoes Ln., P.O. Box 1331, Piscataway, NJ 08854-1331, http:/www.ieee.org.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org5Available from Underwriters Laboratories (UL), 333 Pfingsten Rd., North-bro
14、ok, IL 60062-2096, http:/.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.1 insulating plastic guardsdevices for temporary in-stallation on structures or energized electric power circuits forelectrical protection of personnel or
15、equipment, or both.3.1.2 self extinguishingrelates to a property of a plasticmaterial compounded so as to cease combustion on removal ofthe source that caused ignition.4. Significance and Use4.1 All three tests may be used for product design qualifi-cation.4.2 This specification covers the minimum e
16、lectrical,chemical, and physical properties designated by the manufac-turer and the detailed procedures by which such 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 c
17、oncerningfailure to meet the specification are subject to verification bythe manufacturer.4.3 Plastic guard equipment 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 a
18、t which they are tested. Thisrelationship is shown in Table 1 and Table 2. The equipment isdesigned only for phase-to-ground or covered phase-to-covered-phase exposure.NOTE 1Rubber insulating equipment is realistically limited to Class 4material in the design specification standards. Plastic guard e
19、quipment 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
20、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 isonl
21、y provided if the exposure is covered-phase-to-covered-phase.4.4 Work practices vary from user to user, dependent uponmany factors. These may include, but are not limited to,operating system voltages, construction design, work proce-dure techniques, weather conditions, etc. Therefore, except forthe
22、restrictions set forth in this specification because of designlimitations, the use and maintenance of this equipment isbeyond the scope of this specification.4.5 It is common practice and the responsibility of the userof this type of protective equipment to prepare completeinstructions and regulatio
23、ns to govern in detail the correct andsafe use of such equipment.5. Apparatus5.1 Voltage Source and Test TechniquesSee Test MethodD149. The test equipment shall have adequate power andprovide relatively stepless variable test voltage that can beraised at a rate of approximately 1000 V/s ac or 3000 V
24、/s dc.5.2 Energized Inner Electrodes, in accordance with Table 3and Table 4. The length should be sufficient to extend past theends of the guard or guard assemblies where appropriate.5.3 Outer Ground ElectrodeA conductive material withsize and location as indicated in Table 3.5.4 Shielded CableTo re
25、duce the “room influence” whenconducting ac leakage tests, the cable from the pickup elec-trode to the current-measuring device should be a shieldedcable with the cable shield grounded.6. Sampling6.1 Design tests of each product model shall be conductedto verify that the requirements of Table 1 and
26、Table 2 are met.6.2 Design TestsSamples shall consist of sufficient speci-mens of each product used in a specific guard system to formone of each assembly intended for field use.6.2.1 The design tests will be used to qualify a specificproduct model and normally will not be repeated duringproduction.
27、6.2.2 Acceptance Tests A test sample shall consist of oneor more specimens dependent on the percentage of the lotbeing tested.6.2.3 A lot is represented either by all the guards producedin one production run or in one shipment.6.2.4 Lots of new or unused guards shall have test speci-mens selected at
28、 random.7. Classification7.1 Guards are furnished in three types of materials speci-fied in Section 9 and explained as follows:7.1.1 Type I guards are constructed of plastic materialhaving mechanical impact properties suitable for cold weatherservice.7.1.2 Type II guards have self-extinguishing plas
29、tic con-struction.TABLE 1 Withstand Voltage Proof TestAClass Rating,kVMax Use60 HzProof Test Withstand Voltage(in-service testing)Criteria0-0A0-Ground 0-Ground kVDuration,min60 Hz DC2 14.6 8.4 13.0 18 1 No flashoverother thanmomentaryas a result oftoo-closespacing ofelectrode3 26.4 15.3 24.0 34 14 3
30、6.6 21.1 32.0 45 15 48.3 27.0 42.0 60 0.56 72.5 41.8 64.0 91 0.25ACover-up materials are tested at values greater than the maximum use phaseto ground values. The maximum use phase to phase values relate to guardedphase to guarded phase. The units are not rated for bare phase to guarded phasepotentia
31、ls.TABLE 2 Minimum Flashover TestARating,kVMax Use60 HzMin Flashover VoltageTest f-Ground kVCriteria0-0A0-Ground 60 Hz DC2 14.6 8.4 14.0 20 No flashoverother thanmomentaryas a result oftoo-closespacing ofelectrode3 26.4 15.3 25.0 354 36.6 21.1 34.0 485 48.3 27.0 43.0 616 72.5 41.8 67.0 95ACover-up m
32、aterials are tested at values greater than the maximum use phaseto ground values. The maximum use phase to phase values relate to guardedphase to guarded phase. The units are not rated for bare phase to guarded phasepotentials.F712 06 (2011)27.1.3 Type III guards are constructed of self-extinguishin
33、gplastic material having mechanical impact properties suitablefor cold weather service.7.2 Guards are furnished in three grades in accordance withprovisions for installation as follows:7.2.1 Grade 1 guards have hot stick handles attached forinstallation.7.2.2 Grade 2 guards are equipped with eyes fo
34、r installationwith removable hot sticks.7.2.3 Grade 3 guards are intended for applications where theusual installation is by hand. These guards are equipped withrope loops, or their equivalent, so their removal may beaccomplished with hot sticks.7.2.3.1 ExamplePole guards installed on a pole prior t
35、oraising it close to overhead line conductors. After the pole israised the guard is opened with hot sticks and allowed to slidedown the pole where it can be safely removed by hand.7.3 Guards are made in five classes in accordance with thevoltage ratings in Annex A1.8. Ordering Information8.1 Orders
36、for guards under this specification shall includethe designation ASTM Specification F712 and should includethe following information.8.1.1 Quantity,8.1.2 Name-description of guard or cover,8.1.3 Type, see 7.1.1 through 7.1.3,8.1.4 Grade, see 7.2.1 through7.2.3,8.1.5 Class, see Table 1, Table 2,orTab
37、le 4,8.1.6 Size, if applicable, see Section 11.NOTE 2Atypical ordering description is as follows: 100 Line Guards,ASTM Specification F712, Type I, Grade 1, Class 3A, 4.5-ft long.NOTE 3It is expected that manufacturers will publish catalog dataconforming to this specification that will combine the re
38、quirements of8.1.2 and 8.1.6 in a single product number. With that system, a typicalorder description is: 100 (Smith Manufacturing Co., Product No. XXXX)Line Guards, ASTM Specification F712.9. Materials9.1 Principal construction of insulating body shells shall bein accordance with the material requi
39、rements as follows:9.1.1 Type I GuardsMinimum 1.5 ftlbf/in. (80.06 J/m ofnotch) notched izod impact strength at 20F(29C); maxi-mum water absorption 0.1 % by weight; minimum 380 V/mL(0.025 mm) dielectric strength.9.1.2 Type II GuardsMinimum 1.0 ftlbf/in. (53.4 J/m)notched izod impact strength at 20F
40、(29C); maximumwater absorption 0.5 % by weight; minimum 320 V/mL (0.025mm) dielectric strength; 94 V-O flame retardancy.9.1.3 Type III GuardsMinimum 3.0 ftlbf/in. (160.1 J/mof notch) notched izod impact strength at 20F(29C);maximum water absorption 0.09 % by weight; minimum 300V/mL(0.025 mm) dielect
41、ric strength; 94 V-O flame retardancy.9.1.4 Material ratings for Notched Izod Impact Strengthshall be in accordance with Test Methods D256, Method A.9.1.5 Material ratings for water absorption shall be inaccordance with Test Method D570.9.1.6 Material ratings for dielectric strength shall be inaccor
42、dance with Test Method D149.9.1.7 Material ratings for flame retardancy shall be inaccordance with UL Standard 94.TABLE 3 Typical Electrodes for Testing Plastic Guard EquipmentType of Guards Energized Inner Electrode for All TestsAOuter Ground ElectrodeAProof Test Flashover and Leakage TestsLine gua
43、rds and line guard Round metal tube or bar. Complete electodeBshall be 4 by 6-in. flexible conductive padconnectors spaced back from openings placed alternately on all exteriorInsulator covers and deadened Maximum conductor, hardware and insulator assembly for through which the energized surfaces an
44、d across conductorcovers which rated or similar mock-up including mandrelCof electrode protrudes during the opening of guard and assembledconductive material approximate.Dtest only as necessary to avoid guard system joints spaced backPole guards, ridge pin andERound metal tube, fabricated mandrelCfl
45、ashover. Therefore, the entire from openings through which theswitch blade covers or cluster small metal tubes.Darea of each cover shall be tested energized electrode protrudesas nearly as practical. during the test only as necessaryArm guards Round or rectangular metal tube or fabricated mandrel.DC
46、to avoid flashover at outer ends.Cutout covers Largest cutout with bare leads covered with equal ratedline hose. Or similar mock-up including mandrelCofconductive material.DStructural barrier Rectangular metal sheets approximately 3 mm (0.06 in.)thick, having smoothly rounded edges and corners,have
47、been found to be satisfactory for this purpose.Also satisfactory are wet felt or sponge-top electodes.AMoistened electrodes may be secured with rubber straps or blanket pins. Pressure-sensitive tape is helpful in securing dry metal foil electrodes.BSuitable materials include: metal foil or screen; t
48、ap water-moistened sponge sheeting, or blanket made of wool, or similar material including synthetics.CThin metal sheet or screen wire secured on wood frames make suitable electrodes. Carved synthetic sponge moistened with tap water is suitable for small forms.DThe dimensions of the mandrel are to a
49、pproximate the maximum size of equipment to which the guard system is to be applied.EMetal canisters made for storing rubber blankets make suitable electrodes for pole guard tests.TABLE 4 Inner Electrode SizesClassARatingMax Use Inner Electrode Diameter, in. (mm)kV 60 HzMin Maxf ffGr.2 14.6 8.4 0.25 (6.4) 0.75 (19.1)3 26.4 15.3 0.25 (6.4) 0.75 (19.1)4 36.6 21.1 0.25 (6.4) 0.75 (19.1)5 48.3 27.0 0.50 (12.7) 1.50 (38.1)6 72.5 41.8 0.75 (19.1) 2.00 (50.8)ACover-up materials are tested at values greater than the maximum use phaseto ground
