ANSI IEEE C37.85-1989 Switchgear - Alternating-Current High-Voltage Power Vacuum Interrupters - Safety Requirements for X-Radiation Limits.pdf

1、iANSI C37.85-1989(Revision of ANSI C37.85-1972)American National Standard for SwitchgearAlternating-Current High-Voltage Power Vacuum InterruptersSafety Requirements for X-Radiation LimitsSecretariatNational Electrical Manufacturers AssociationInstitute of Electrical and Electronics EngineersApprove

2、d October 17, 1988American National Standards Institute, InciiForeword(This Foreword is not part of American National Standard C37.85-1989.)This standard was developed initially by a task force of the NEMA Switchgear Section as a result of an industry studyundertaken at the request of the Bureau of

3、Radiological Health in order to meet the need as set forth in Public Law 90-602, identified as Radiation Control for Health and Safety Act of 1968.Upon completion, the initial proposal was submitted to the American National Standards Committee C37 on PowerSwitchgear for further development and in or

4、der to obtain a consensus as an American National Standard. It wasapproved on April 28, 1972 as American National Standard for Safety Requirements for X-Radiation Limits for ACHigh-Voltage Power Vacuum Interrupters Used in Power Switchgear, ANSI C37.85-1972. This standard set forth performance requi

5、rements relative to X-radiation emission and methods of test for high-voltagevacuum switching devices. The 1988 revision incorporates higher-voltage vacuum interrupters that have beendeveloped, tested, and placed into service since the 1978 reaffirmation and that meet the requirements of this standa

6、rd.Suggestions for improvement of this standard will be welcome. They should be sent to the National ElectricalManufacturers Association, Inc, 2101 L Street, NW, Washington, DC 20037.This standard was processed and approved for submittal to ANSI by Accredited Standards Committee on PowerSwitchgear,

7、C37. Committee approval of the standard does not necessarily imply that all members voted for itsapproval. At the time it approved this standard, the C37 Committee had the following members:W. E. Laubach, Chair A. K. McCabe (Executive Vice-Chair, High-Voltage Standards)S. H. Telander (Executive Vice

8、-Chair, Low-Voltage Standards)D. L. Swindler (Executive Vice-Chair, International Electrotechnical Commission Activities)C. H. White, Secretary M. B. Williams (Program Administrator)Organization Represented Name of RepresentativeAssociation of Iron and Steel Engineers J. M. TillmanElectric Light and

9、 Power Group R. L. Capra (Chair)D. A. DitzlerK. D. HendrixJ. H. ProvanzanaD. T. WestonT. E. Bruck (Alt)D. E. Soffrin (Alt)Institute of Electrical and Electronics Engineers, Inc H. W. Mikulecky (Chair)W. F. HoenigmannD. M. LarsonE. W. SchmunkC. A. SchwalbeS. C. Atkinson (Alt)D. G. Kumbera (Alt)iiiThe

10、 C37 Subcommittee on X-Radiation Limits for AC High-Voltage Power Vacuum Interrupters for Use in PowerSwitchgear, which developed this standard, had the following members:P. O. Wayland, Chair B. H. Schultz (Working Group Chair)C. H. White, Secretary M. B. Williams (Program Administrator)K. Goodman H

11、. K. ReidW. N. RothenbuhlerR. L. WalchleNational Electrical Manufacturers Association R. A. McMaster (Chair)T. C. BurtnettR. H. MillerR. 0. D. WhittH. L. Miller (Alt)Tennessee Valley Authority R. B. RottonTesting Laboratory Group L. FrierW. T. OGradyR. W. Seelbach (Alt)U.S. Department of Agriculture

12、Rural Electrification AdministrationH. L. BowlesU.S. Department of the ArmyOffice of the Chief of EngineersW. M. JonesU.S. Department of the InteriorBureau of Reclamation J. W. ReifU.S. Department of the NavyNaval Construction Battalion CenterR. L. ClarkWestern Area Power Administration G. D. Birney

13、Organization Represented Name of RepresentativeivCLAUSE PAGE1. Scope.12. Related American National Standards 13. Definitions.14. Performance Requirements .25. Conformance Test Procedures for New Interrupters 35.1 General Requirements 35.2 Test Voltage and Measurement Procedure 46. Dielectric Withsta

14、nd Voltage Tests on Used Interrupters 57. Labeling 5Annex A (Informative) Report on the Basis of Derivation of the Maximum Permissible Levels ofX-Radiation Emitted by High-Voltage Power Vacuum Interrupters6Annex B (Informative) Testing in Assembled Switchgear81American National Standard for Switchge

15、arAlternating-Current High-Voltage Power Vacuum InterruptersSafety Requirements for X-Radiation Limits1. ScopeThis standard specifies the maximum permissible X-radiation emission from alternating-current high-voltage powervacuum interrupters that are intended to be operated at voltages between 5000

16、volts and 38 000 volts when tested inaccordance with procedures described in this standard.NOTES:1 The test procedures prescribed in this standard are not necessarily applicable for higher-voltage vacuum interrupters.2 In this standard, the term “Interrupter” signifies “high-voltage power vacuum int

17、errupter,” unless qualified by otherdescriptive terms.2. Related American National StandardsThe following standards are listed for information only and are not essential to complete the requirements of thisstandard.ANSI/NBS 114-1974, General Safety Standard for Installations Using Non-Medical X-Ray

18、and Sealed Gamma-RaySources, Energies up to 10 MeVANSI/IEEE C37.100-1981 and C37.100b-1985, Definitions for Power Switchgear3. DefinitionsThe definitions and terms contained in this standard, or in other American National Standards referred to in thisstandard, are not intended to embrace all legitim

19、ate meanings of the terms. They are applicable only to the subjecttreated in this standard. For additional definitions of terms used in this standard, see ANSI/IEEE C37.100-1981 andC37.100b-1985. An asterisk (*) following a definition indicates that, at the time this standard was approved, there was

20、no corresponding definition in ANSI/IEEE C37.100-1981 and C37.100b-1985.2 Copyright 1998 IEEE All Rights ReservedANSI C37.85-1989 AMERICAN NATIONAL STANDARD FOR SWITCHGEARALTERNATING-CURRENT HIGH-VOLTAGEconformance tests: Those tests that are specifically made to demonstrate the conformity of switch

21、gear or itscomponent parts with applicable standards.dielectric withstand voltage tests: Tests made to determine the ability of insulating materials and spacings towithstand specified over-voltages for a specified time without dielectric breakdown or puncture.high-voltage power vacuum interrupter: A

22、n interrupter in which the separable contacts function within a singleevacuated envelope and that is intended for use in power switchgear.*maximum interrupter operating voltage: The highest steady-state alternating-current rms operating voltage thatwill appear across the open contacts of a vacuum in

23、terrupter in its application.*NOTE The maximum interrupter operating voltage is a function of the highest system voltage on which a switchgear deviceemploying vacuum interrupters is to be applied, the number of interrupters used in series, and whether the device issingle-phase or three-phase.milliro

24、entgen (mR): The amount of X-radiation that produces 2.58 107 coulomb per kilogram of air.*shielding: The barrier of attenuating material used to reduce radiation hazards.*4. Performance RequirementsInterrupters, tested as specified in Section 5., shall be in compliance with this standard if the X-r

25、adiation emitted doesnot exceed the following:1) 0.5 milliroentgen per hour at the maximum operating voltage shown in column 2 of Table 1.2) 15.0 milliroentgens per hour at the low-frequency dielectric withstand test voltage shown in column 3 ofTable 1.Table 1 X-Radiation Test Voltages for Interrupt

26、ers Applied Without Additional External ShieldingRated Maximum Voltage (kV rms)* (Column 1)*Table 1 will be expanded in future revisions of this standard as additional ratingsbecome available.X-Radiation Test VoltagesRefer to Appendix B for the derivation of the test voltages.Maximum Interrupter Ope

27、rating Voltage (kV rms)(Column 2)Low-Frequency Test Voltage(kV rms) (Column 3)15.5 15.5 37.525.827.0 27.0 45.038.0 38.0 52.5For interrupters used in switchgear having a normal low-frequency withstandtest voltage of 70 kv rms.38.0 38.0 60.0*For interrupters used in switchgear having a normal low-freq

28、uency withstandtest voltage of 80 kv rms.Copyright 1998 IEEE All Rights Reserved 3POWER VACUUM INTERRUPTERSSAFETY REQUIREMENTS FOR X-RADIATION LIMITS ANSI C37.85-1989 5. Conformance Test Procedures for New Interrupters5.1 General Requirements5.1.1 Condition of Interrupter to Be TestedWhen conformanc

29、e tests are to be performed, the interrupter shall be new and in good condition and tests shall beperformed before it is put into commercial service.5.1.2 Mounting of SpecimenThe interrupter shall be mounted in a test fixture, designed so that the open contact spacing may be set at the suppliersreco

30、mmended minimum distance, and which will permit the application of a test voltage to one terminal of theinterrupter while the other terminal is grounded. Interrupters designed for operation in an insulating medium otherthan air (such as oil or SF6) may be tested in such a medium, if necessary, to wi

31、thstand the test voltage.The container for the insulating medium shall be of an insulating material having radiation attenuation no greater thanthat afforded by 3/8-inch-thick methyl methacrylate. The insulating medium between the interrupter and radiationinstrument shall be the minimum required for

32、 dielectric purposes.5.1.3 Test CircuitThe interrupter shall be connected to a power source of alternating-current voltage with a means for varying thevoltage across the open contacts of the interrupter. A sine wave having a crest value not exceeding 1.414 times the rmsvalue shall be applied.5.1.4 F

33、requencyThe frequency of the supply voltage shall be 60 hertz 5 percent.5.1.5 Radiation InstrumentA radio frequency (RF) shielded radiation survey instrument1 having the following minimum specifications shall beused:Accuracy: Capable of measuring 15 milliroentgens per hour with an accuracy of 25 per

34、cent with aresponse time not to exceed 15 secondsEnergy Response: 12 kiloelectron volts to 0.5 mega-electronvolts 15 percentSensitive Area: 100 cm2, maximum.5.1.6 Location of Radiation InstrumentThe sensing element of the radiation instrument shall be positioned in the plane of the separable contact

35、s and pointedat the contacts from a distance of 1 meter from the nearest external surface of the interrupter (see Figure 1). Whenelectrical safety requires the instrument to be located at a distance greater than 1 meter, the instrument reading shall beadjusted by applying the inverse square law.1Vic

36、toreen Instrument Company Model 440RF was used during the development of this standard.4 Copyright 1998 IEEE All Rights ReservedANSI C37.85-1989 AMERICAN NATIONAL STANDARD FOR SWITCHGEARALTERNATING-CURRENT HIGH-VOLTAGE5.1.7 PrecautionsIf distances normally required for electrical safety are maintain

37、ed, the exposure to test personnel will generally notexceed established dose limits (see ANSI/NBS 114-1974). Nevertheless, adequate precautions such as shielding ordistance should be used to protect test personnel against possible higher X-radiation occurrences due, for example, toincorrect contact

38、spacing, or to the application of voltages in excess of those specified in 5.2.5.2 Test Voltage and Measurement ProcedureWith the interrupter mounted in a test fixture, with the contacts blocked open at the minimum contact spacing specifiedby the supplier, and with the radiation instrument in place

39、(see Figure 1), a voltage shall be applied across theinterrupter contacts equal to the maximum interrupter operating voltage shown in Column 2 of Table 1. After aminimum of 15 seconds, the X-radiation level on the radiation instrument shall be read.Next, the voltage across the interrupter contacts s

40、hall be raised to a value equal to the low-frequency insulationwithstand test voltage shown in Column 3 of Table 1. After a minimum of 15 seconds, the X-radiation level on theradiation meter shall be read.Figure 1 Test Location of Radiation MeterCopyright 1998 IEEE All Rights Reserved 5POWER VACUUM

41、INTERRUPTERSSAFETY REQUIREMENTS FOR X-RADIATION LIMITS ANSI C37.85-1989 6. Dielectric Withstand Voltage Tests on Used InterruptersDielectric withstand voltage tests should be performed by users of switchgear devices, as part of a preventivemaintenance program, to prove the ability of insulating mate

42、rials and spacings to withstand specified over-voltages forspecified times without dielectric breakdown or puncture. The test voltage levels used for field tests are typically 75percent of the levels used on new equipment by the suppliers.Dielectric withstand voltage tests may also be used to establ

43、ish the vacuum integrity of vacuum interrupters. Suppliersshall prescribe the test procedures, including gap settings and test voltages, for conducting dielectric withstand voltagetests on used vacuum interrupters or switchgear utilizing vacuum interrupters.When dielectric withstand voltage tests ar

44、e performed on used vacuum interrupters, or on switchgear utilizing vacuuminterrupters, precautions shall be taken for the safety of test personnel. If distances normally required for electricalsafety are maintained, X-radiation exposure to test personnel generally does not exceed established dose l

45、imits (seeANSI/NBS 114-1974). Nevertheless, adequate precautions such as shielding or distance should be used to protectpersonnel against possible higher X-radiation occurrences due, for example, to incorrect contact spacing, or to theinadvertent application of voltages in excess of the values presc

46、ribed in Column 3 of Table 1.7. LabelingEach interrupter prepared for shipment shall have at least the following wording on its outer surface:CAUTION Read Instructions Before EnergizingThis Device May Produce Harmful X-Rays6 Copyright 1998 IEEE All Rights ReservedANSI C37.85-1989 AMERICAN NATIONAL S

47、TANDARD FOR SWITCHGEARALTERNATING-CURRENT HIGH-VOLTAGEAnnexes (Informative)(These Appendixes are not part of American National Standard C37.85-1989, but are included for information only.)Annex A Report on the Basis of Derivation of the Maximum Permissible Levels of X-Radiation Emitted by High-Volta

48、ge Power Vacuum Interrupters(Informative)The known United States manufacturers of vacuum interrupters initiated a test program during July of 1968 (as a TaskForce of the NEMA Switchgear Section) to determine the present levels of X-radiation, if any, being emitted fromhigh-voltage power vacuum inter

49、rupters, and to suggest permissible levels of radiation from such interrupters on thebasis of their recognized application.Each manufacturer conducted a series of tests on new vacuum interrupters taken from stock and recorded the X-radiation levels, if any, under the following conditions:1) Dielectric withstand test voltage applied to new interrupters2) Fault current interruption (where applicable)3) Load current interruption4) Dielectric withstand test voltages after fault current interruption5) Dielectric withstand test voltages after