US3769538A - Vacuum arc devices with ferrous electrodes - Google Patents

Vacuum arc devices with ferrous electrodes Download PDF

Info

Publication number
US3769538A
US3769538A US00236278A US3769538DA US3769538A US 3769538 A US3769538 A US 3769538A US 00236278 A US00236278 A US 00236278A US 3769538D A US3769538D A US 3769538DA US 3769538 A US3769538 A US 3769538A
Authority
US
United States
Prior art keywords
arc
electrode
vacuum
ferrous
members
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00236278A
Other languages
English (en)
Inventor
L Harris
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
General Electric Co
Original Assignee
General Electric Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by General Electric Co filed Critical General Electric Co
Application granted granted Critical
Publication of US3769538A publication Critical patent/US3769538A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
    • H01H33/60—Switches wherein the means for extinguishing or preventing the arc do not include separate means for obtaining or increasing flow of arc-extinguishing fluid
    • H01H33/66—Vacuum switches
    • H01H33/664—Contacts; Arc-extinguishing means, e.g. arcing rings
    • H01H33/6646—Contacts; Arc-extinguishing means, e.g. arcing rings having non flat disc-like contact surface
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H33/00—High-tension or heavy-current switches with arc-extinguishing or arc-preventing means
    • H01H33/02—Details
    • H01H33/04—Means for extinguishing or preventing arc between current-carrying parts
    • H01H33/20—Means for extinguishing or preventing arc between current-carrying parts using arcing horns

Definitions

  • Vacuum are devices having a pair of primary arc- [21] Appl. No.: 236,278
  • electrode assemblies in the form of a rod array struc- 313,311 ture utilize hardened ferrous materials exhibiting high hardness, ductility and high recovery strength for the 7 Q6 12 s 4 2 3 3 3/ 3 1 3 1.
  • the present invention relates to improved vacuum are devices. More particularly, the invention relates to such improved devices as vacuum gaps, triggerable vacuum gaps, vacuum switches and the like, wherein a rod array structure of interleaved individual arc electrode members presents a large arcing surface for the attainment of high current and low current density power arcing characteristics.
  • vacuum arc devices such as vacuum gaps and vacuum switches, a number of problems have been encountered and solved.
  • While devices of the Rich invention are a great advance upon the art and make possible the attainment of heretofore unobtainable current-interrupting and current-carrying capacities without the formation of anode spots, the utilization of conventional arcelectrode materials as, for example, zone-refined OFHC copper, does not over-come the disadvantage existing in previous vacuum arc devices wherein such materials do not exhibit a high enough recovery strength nor dielectric hold-ofi' strength to accommodate higher voltages and further possess certain limitations in physical strength which limit the currentinterrupting capacities.
  • Still another object of the present invention is to pro vide such vacuum arc devices as possess improved mechanical strength which facilitates the attainment of higher current interruption than devices of the prior art.
  • Yet another object of the present invention is to provide improved vacuum are devices suitable for holding off higher voltages, interrupting higher currents, operating with better electrical characteristics than devices of the prior art and which are fabricated from inexpensive materials which do not require expensive fabrication processes.
  • vacumm are devices in accord with the invention include a pair of primary arc electrode assemblies each of which comprises a base plate and a plurality of rod-like arcing members normal thereto formed in a substantially circular pattern and adapted, so that when a pair of oppositely-poled assemblies are interleaved with one another, a plurality of electrically parallel arcing paths are formed.
  • arc electrode assemblies are fabricated of a gas-free hardened ferrous material which exhibits a high hardness and ductility and a higher dielectric strength than materials previously utilized in such applications.
  • FIG. 1 is a schematic vertical cross-sectional view constructed in accord with the present invention.
  • FIG. 2 is a plan view taken along the lines 22 of the device of FIG. 1.
  • FIG. 3 is a graphical representation of the voltage recovery characterics of arc electrodes in vacuum fabricated of materials utilized in the construction of devices in accord with the present invention as compared with the similar characteristics of arc-electrodes fabricated of materials normally used in vacuum arc devices.
  • FIG. 4 is a schematic vertical cross-sectional view of a triggerable vacuum gap device constructed in accord with the present invention.
  • FIG. 5 is a schematic vertical cross-sectional view of a vacuum switch constructed in accord with the present invention.
  • FIG. 1 a vacuum gap device constructed in accord with the present invention is represented generally at 10.
  • Device 10 includes an upper arc-electrode assembly 11 and a lower arc-electrode assembly 12 which are joined by an insulating cylindrical sidewall member 13 hermetically sealed to upper and lower electrode assemblies 11 and 12 to form an hermetically-sealed evacuable envelope 14.
  • Upper arc-electrode assembly 11 includes a base plate or disk member 15 and a plurality of downwardly-depending electrode members 16 electrically and mechanically attached thereto.
  • Lower electrode assembly 12 includes a base plate or disk member 17 and a plurality of upwardly-depending electrode members 18 electrically and mechanically attached thereto and disposed in perpendicular relationship therewith, as are the electrode members 16 with respect to baseplate member 15.
  • Each of electrode members 16 and 18 are solid, smooth-surfaced rod-like members, as illustrated. Although a cylindrical geometry is believed ideal, it is within contemplation of the invention that rounded wedge-shaped or radial vanes with no sharp edges may also be used for attainment of increased arcing area.
  • Envelope 14 is completed and seals are made by the provision of conventional ceramic-to-metal seals by collar-shaped seal members 22 and 23 which seal upper electrode and lower electrode assemblies to insulating sidewall member 13, respectively. These seals are protected from the deleterious effects of being exposed to an electron-ion plasma caused during intense arcing conditions within envelope 14 by the provision of end shields 24 and 25 connected to stepped peripheral portions of endwall members and 17, respectively.
  • insulating sidewall member 13 which may for example be a glasssuch as General Electric REX or Corning Pyroceram or a higher density alumina or any of the many vacuum tight glasses well known to the art, is further protected by a doubly truncated cylindrical central shield member 26 which is supported laterally about the region in which arc electrode members 16 and 18 overlap and which overlaps the inwardly-depending ends of end shields 24 and 25. Shield 26 is supported by shield support member 27 which is secured in ceramic-to-metal bond within the central portion of insulating sidewall member 13.
  • a pair of terminal members 28 and 29 comprise means for connecting the device 10 of FIG. 1 in circuit with an electric circuit or circuit element to be protected.
  • Terminal members 28 and 29 are in good nonresistive electrical contact with arc electrode assemblies l1 and 12, respectively, and are adapted to conduct hundreds of kiloamperes.
  • ferrous materials provide unique advantages in the state of the art to which it has developed for the attainment of very high current interruption and the maintenance of high dielectric strength.
  • the degassification of ferrous matierals is relatively simple.
  • Initial degassification of the bulk material may be provided by vacuum melting, particularly of the consumable electrode type vacuum melting wherein each portion of a ferrous bar from which the finally utilized ferrous electrode is formed is at one point the arcing point of a vacuum arc and each portion of the arc electrode source material is melting under vacuum conditions to cause the removal of all gas and gasforming constituents before formation of the electrode.
  • Ferrous materials may be degassified of adsorbed gases merely by assembling them in the vacuum arc device and during normal bakeout subjecting them to the temperature and time of bakeout necessary to degassify the other materials in the device. No special precautions need to be taken.
  • ferrous materiala particularly hardenable steels which have high ductility, rather than cuprous materials precludes deformation of the rods for currents which materials, attainable within the limitations of other parameters of such devices so that possible deformation of individual rods vanishes as a problem, thus creating another advantage for the use of ferrous materials.
  • ferrous metals as used in accord with the invention are usually very hard and reasonably ductible.
  • age hardening or precipitation hardening steels are well known and generally identified as age hardening or precipitation hardening steels.
  • these steels are martensitic steels obtained by quenching rapidly an austenitic steel to obtain dispersion of impurities and small grain size. Hardening is effectuated by the presence of impurities, which also contribute to the necessary ductility. The hardening may result from a heat treatment generally performed at a relatively low temperature (as compared with the temperature of the original quenching), as for example between 900-1000 F.
  • Some such steels are iron-nickel maraging steels (generally containing also minor quantities of molybdenum and cobalt, and sometimes titanium) with from 15 to 30 weight percent nickel.
  • Maraging steels are often manufactured by vacuummelting practices and are relatively free of dissolved gases as commercial steels go. Developmental tests have verified that the gas contents of these steels is acceptable for use in arc electrodes in vacuum are devices.
  • maraging steels may typically have a hardness of approximately 30 Rockwell C and exhibit a yield strength of approximately 100,000 psi, approximately six times that of copper. In this condition the steels are, nevertheless, readily machinable, much more so than copper. After machining, forming and other preparation for assembly into the devices of the invention, the maraging steels may be hardened by a high-temperature aging treatment, the temperature and time of which may be varied compatibly to achieve the useful result.
  • a typical 30 Rockwell C 100,000 psi maraging steel after treatment at 520 C for approximately three hours, exhibits a hardness of 54 Rockwell C and a yield strength in excess of 250,000 psi with remarkably high ductility in excess of percent of 2 inch standard section.
  • Such characteristics are uniquely adapted for the formation of electrode assemblies in vacuum arc devices since the bakeout and curing time of such devices may be made sufficient to cause appropriate hardening of a marging steel.'i"hus, for example, I have constructed vacuum devices in accord with the present invention utilizing a particular maraging steel known as Vascomax 300 CVM to form arc-electrode members exhibiting the foregoing mechanical characteristics.
  • a similar Vascomax 300 CVM maraging steel having a 30 Rockwell C hardness was machined to provide base plates 15, 17 and rods 16, 18 of vacuum arc electrode assemblies in accord with the present invention, assembled, and the device was baked out for 24 hours at 550C. After such treatment, the steel was found to exhibit a hardness of approximately 41 Rockwell C and a corresponding yield strength of 150,000 psi, at least ten times stronger than conventional vacuum processed OFHC copper, generally utilized in such devices and a ductility in excess of 10 percent. As is mentioned hereinbefore, for short term arcing characteristics, the steels of the invention are comparable to copper insofar as arcing current-carrying capacity is concerned.
  • Vascomax 300 steel utilized as described herein have shown an ability to carry without deleterious effect a current density of approximately 225 amperes/cm over the surface thereof for a half cycle of arcing, which exceeds the same value as may be carried by copper electrodes.
  • Other hardened or hardenable steels from which ferrous arc-electrodes for use in devices in accord with the invention are made include precipitation hardened stainless steel such as those set forth on pages 81 and 83 of the 1972 Materials Selector published by Materials Engineering Journal, Stamford, Connecticut.
  • precipitation-hardened stainless steels no one of which is unique in desirable properties as used herein, usually contain low carbon, high nickel and chromium and minor precipitates of other elements. They are generally hard, having tensile strengths in excess of 150,000 and usually in excess of 200,000 psi, are easily outgassed and have ductility of the order of 10 percent elongation of standard 2 inch section.
  • Many other precipitation hardened stainless, austenitic and martensitic steels may be found therein.
  • Carpenter Custom 455 One specific precipitation hardened stainless steel possessing characteristics ideally adapted for use in devices in accord with the invention is identified as Carpenter Custom 455 and is available from Carpenter Technology Corporation, Reading, Pennsylvania. This steel contains approximately 12 percent chromium, 8.5 percent nickel, 1.2 titanium, 2.25 percent copper, less than 1 percent each of carbon, manganese and columbium, balance iron. Its tensile strength is in excess of 225,000 psi, readily outgassed and has high ductility as represented by a 5-10 percent elongation in a standard 2 inch test section.
  • TRIP steels Transformation Induced Plasticity
  • Such steels are normally austenitic, but their composition places them near the phase line so that warm working causes a transformation to martensite under stress at service temperatures.
  • a description of TRIP steels may be found in an article appearing in preprint No. -UCRL 18609 (Lawrence Radiation Laboratory), University of California, November 1968, by W. W. Gerberich and entitled Metastable Austenitic Steels With Ultrahigh Strength and Toughness.” See also TRANS. ASM 60, 252 (l967), The Enhancement of Ductility in High Strength Steels by Zackey et al.
  • Carbon alloy steels on the other hand, as is epitomized, for example, by Vascojet 1000 CFM, a carbon alloy steel'available from Vanadium Alloy Steel Co., Latrobe, Pennsylvania, and comprising approximately 0.40 percent carbon, 5.0 percent chromium, 3 percent molybdenum, 0.5 percent vanadium, the remainder iron, are hardened by a quench from a high temperature (l800-l900F for Vascojet) and later tempered to slightly decrease the hardness and increase theductility by exposure to intermediate temperatures such as those utilized in the bakeout of vacuum arc devices in accord with the present invention. 7
  • the terms hardness, hard and the like are intended to connote a tensile strength in excess of 100,000 psi and preferably in excess of 150,000 psi.
  • the terms high ductility ductile and the like are meant to connote a ductility as evidenced by a percentage elongation of a standard 2 inch long sample of standard cross section of at least percent and preferably 10 percent. All percentages of compositions are expressed in weight percent.
  • FIG. 3 of the drawing illustrates a typical plot of recovery strength in volts plotted as a function of time after arcing of gas-free arc-electrodes of a specific configuration utilized in vacuum are devices of the present invention fabricated from different electrode materials and tested under identical test conditions.
  • the voltage recovery strength of arc electrodes fabricated from cuprous and ferrous materials increases rapidly at a rate of approximately 15 kilovolts per microsecond on a more or less straight line characteristic and saturates at a value which is dependent upon the material of the electrode and its physical characteristics, principally hardness.
  • the graph of FIG. 1 the graph of FIG. 1
  • the curve representing cuprous electrodes saturates at 30 kilovolts while the curve representative of electrodes of Vascomax 300 maraging steel as an example of hard ferrous electrodes does not saturate until kilovolts, nearly three times higher than that for the copper electrodes, thus making it possible for devices constructed in accord with the present invention and utilizing such hard ferrous alloy electrodes to operate at greatly increased voltages without the danger of spurious breakdown or, in the alternative, to locate the arc electrodes much closer together for a given holdoff voltage.
  • This characteristic seems to be associated with hardness of the electrode and therefore is to be found in other hard ferrous metal electrodes as well.
  • Devices constructed in accord with the invention have been operated repeatedly to hold off 100,000 volts in open circuit position. In closed circuit position, they have routinely successfully carried 33,000 amperes peak current. This current has been interrupted successfully by causing arc to be struck which exhibits a 50 V are drop and which has been extinguished at a first current zero with no noticeable deleterious effects to the arc-electrodes and the applied voltage held off without restrike.
  • FIG. 4 of the drawings illustrates a triggerable vacuum gap device 30 in accord with the present invention which is a modification of the device of FIG. 1.
  • Triggerable vacuum arc device 30 includes envelope 14 and its constituent parts, as illustrated in FIG. 1.
  • a trigger electrode assembly 31 is electrically connected at one terminal thereof to lower endplate l7 and includes a metallic plated and scored insulator 32, a trigger anode 33, and a trigger anode connector 34.
  • Trigger assembly 31 may conveniently be any of the trigger assemblies set forth in Lafferty US. Pat. Nos. 3,394,281, 3,465,192 and 3,465,205, or the functional equivalents thereof.
  • the trigger is operative, with the electrode assembly 12 momentarily negatively biased, to receive a positive pulse to trigger anode lead 34, causing the establishment of a trigger arc between trigger anode 33 and the surface of arc electrode plate 17 to cause the injection of an electron ion plasma into the volume of envelope l4 and the breakdown of the respective interelectrode gaps 21 to cause the main voltage applied between terminals 28 and 29 to establish parallel arcs, the aggregate of which may be in the hundreds of kiloamps range between the individual arc electrode rods 16 and 18 of arc electrode assemblies 11 and 12.
  • normally triggerable vacuum arc device 30 may be connected across a circuit constituent as, for example, a capacitor to be protected.
  • conduction species which are the metallic particles ejected from the arc electrode assemblies, condense on the shield and the electrodes. This occurs very rapidly in view of the rapid dielectric strength recovery characteristic of the ferrous arc electrode materials in accord with the present invention, as described hereinbefore.
  • the arc is then not restruck upon the next half-cycle of the alternating voltage and the device remains in the nonconducting, equilibrium state until the next trigger operation occurs.
  • FIG. of the drawings illustrates a vacuum switch constructed in accord with the present invention.
  • the switch 40 of FIG. 5 wherein like numerals are used to identify like parts to those of the device of FIG. 1, comprises an array of a pair of arc electrode assemblies 11, 12, constructed of hard, ductile ferrous materials, as described hereinbefore, but also containing a pair of butt-type electrical contacts 41, 42 which constitute means for providing an electron-ion plasma within the arcing chamber of envelope 40.
  • this device may be utilized in a closed circuit condition and the starter electrodes 41 and 42, which are respectively mounted upon fixed supportrod 43 and movable support rod 44, which is connected through bellows means 45 to an actuating arm (not shown), carry the steady-state current.
  • the ferrous materials of the present invention are not adapted to carry a steady-state high circuit in vacuum arc devices in accord with the present invention.
  • the central portions 46 and 47 of support rods 43 and 44, respectively are normally fabricated from copper, silver, alloy or equivalent conductor which exhibits a low resistivity so as not to cause excessive heating and other deleterious effects.
  • Such cuprous and equivalent low resistivity materials are ideally not suited for exposure to the operation of the device under arcing conditions, however. Should this occur, the vapor pressure of the copper or cuprous alloy could cause the emission of copper or other vapor which may deposit upon the surface of the ferrous arc electrode and shield members of the device so as to degrade the dielectric strength and the recovery characteristics of the device.
  • a pair of cladding members 48 and 49 which may for example be cylindrical'in nature, are press-fitted, or otherwise caused to enclose totally any surface of support members 43 and 44 that is within envelope 14, so that the only materials exposed to the operation of the highcurrent arc during operation are ferrous materials.
  • the device 40 of FIG. 5 is in a normally conductive condition with current flowing through the support members 43 and 44 and across contacts 41 and 42 which are ferrous, as is described hereinbefore, but of minimal thickness so as not to cause undue heating.
  • a mechanical system (not shown) may be actuated to cause the movable support member 44 to be urged outwardly, as indicated by arrow 50, to cause the establishment of an interelectrode gap between now separated starter electrodes 41 and 42.
  • a triggerable vacuum switch may function by the addition of the trigger electrode structure as illustrated in the triggerable vacuum gap device 30 of FIG. 4 which may be actuated instantaneously upon the occurrence of a fault or overvoltage to change the device to the closed circuit condition and cause the fault current to be distributed across the rod array of assemblies 11, 12 even before the approaching starter electrodes 41 and 42 have an energeticity to close and carry the fault current.
  • the invention disclosed herein is applicable to a variety of devices, all of which are characterized as vacuum arc devices, but which may be switches, reclosers, gaps, triggered vacuum gaps, or the like. Accordingly, it is within the true spirit and scope of the invention that such applications of the principles of this invention to similar devices as fall within the purview of one skilled in the art shall be considered a practice of the invention.
  • a vacuum arc device adapted tp carry high currents at high voltages and comprising:
  • a first primary arc electrode assembly disposed within said envelope and including a first plurality of spaced, substantially parallel, rod-like electrode members having smooth arcing surfaces extending substantially'normal to a first common base member;
  • a second primary arc electrode assembly within said envelope and including a second plurality of spaced, substantially parallel, rod-like electrode members having smooth arcing surfaces extending substantially normal to a second common base 'member and interleaved in alternating sequence between the spaced electrode members of said first arc electrode assembly;
  • said first and second spaced electrode members being positioned so as to form a ring-like array of electrode members within said envelope, said members alternating in polarity about said ring;
  • said electrode assemblies comprising ferrous material having a hardness as evidenced by a tensile strength of at least 100,000 psi and a ductility as evidenced by at least a percent elongation of a standard two inch long sample of standard ductility test cross section and having a substantial freedom of sorbed gases and gas-forming impurities therein so as to withstand arcing current densities of approximately 200 amperes/cm for a half-cycle of power-alternating voltage without the emission of any substantial quantityof gaseous material inconsistent with continued maintenance of said low pressure after having been arced thereby;
  • g. means connecting said arc electrode assemblies in circuit with an electric load.
  • said first electrode assembly includes an upper base member and a plurality of downwardly-depending smooth surface, rod-like electrode members and said second electrode assembly includes a base member and aplurality of upwardlydepending smooth surface, rod-like electrode members.
  • each of said ferrous electrode assemblies is a vacuum-melted steel.
  • ferrous electrode assemblies are fabricated from hardened steel having a Rockwell C hardness in excess of 30, a yield strength in excess of approximately 150,000 psi, and a ductility corresponding to an elongation of at least approximately percent of a 2 inch long standard cross section test sample.
  • ferrous material is a carbon alloy steel having from 0.2 to 0.6 weight percent carbon therein.
  • ferrous assemblies are fabricated of a temperature annealing steel which increases in ductility during vacuum bakeout cycles used to fabricate vacuum arc devices of the order of 500 600 C.
  • the device further includes means for establishing an electric arc between said arc electrode assemblies by establishing an electron-ion plasma therebetween.
  • the device of claim 9 wherein said device is a triggerable vacuum gap device and the means for supplying an electron-ion plasma therein is a trigger electrode assembly.
  • said starter electrode assembly constitutes a pair of arc electrodes located at the approximate longitudinal axis of said array.
  • ferrous assemblies are fabricated of age-hardened steel which increases in hardness and yield strength during vacuum bakeout cycles used to fabricate vacuum are devices.

Landscapes

  • Plasma Technology (AREA)
  • High-Tension Arc-Extinguishing Switches Without Spraying Means (AREA)
US00236278A 1972-03-20 1972-03-20 Vacuum arc devices with ferrous electrodes Expired - Lifetime US3769538A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US23627872A 1972-03-20 1972-03-20

Publications (1)

Publication Number Publication Date
US3769538A true US3769538A (en) 1973-10-30

Family

ID=22888857

Family Applications (1)

Application Number Title Priority Date Filing Date
US00236278A Expired - Lifetime US3769538A (en) 1972-03-20 1972-03-20 Vacuum arc devices with ferrous electrodes

Country Status (6)

Country Link
US (1) US3769538A (enrdf_load_stackoverflow)
JP (1) JPS496435A (enrdf_load_stackoverflow)
CA (1) CA977407A (enrdf_load_stackoverflow)
DE (1) DE2308913A1 (enrdf_load_stackoverflow)
FR (1) FR2176902B1 (enrdf_load_stackoverflow)
GB (1) GB1401867A (enrdf_load_stackoverflow)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3825789A (en) * 1973-06-29 1974-07-23 Gen Electric Vacuum arc devices with hard, ductile, ferrous electrodes
US3851203A (en) * 1973-07-30 1974-11-26 Gen Electric Vacuum arc devices with improved arcing shields
US3969598A (en) * 1975-02-03 1976-07-13 General Electric Company Vacuum-type circuit interrupter with a plurality of sets of contacts in parallel
US4063126A (en) * 1977-02-16 1977-12-13 General Electric Company Vacuum arc discharge device with tapered rod electrodes
US4128748A (en) * 1976-07-21 1978-12-05 General Electric Company High-current vacuum switch with reduced contact erosion
JPS5441473A (en) * 1977-09-02 1979-04-02 Electric Power Res Inst High voltage two stage trigger type vacuum gap device
WO1990003657A1 (de) * 1988-09-22 1990-04-05 Siemens Aktiengesellschaft Vakuumschaltröhre, eine solche schaltröhre enthaltender lasttrennschalter und verfahren zum betrieb eines solchen lasttrennschalters
EP0924729A3 (en) * 1997-12-16 2000-05-10 Kabushiki Kaisha Toshiba Electrode arrangement of vacuum circuit breaker with magnetic member for longitudinal magnetization
EP1039495A3 (de) * 1999-03-23 2001-08-08 Siemens Aktiengesellschaft Verfahren zur Strombegrenzung in Niederspannungsnetzen, zugehörige Anordnung sowie spezielle Verwendung dieser Anordnung
US20020153353A1 (en) * 2001-04-19 2002-10-24 Mitsubishi Denki Kabushiki Kaisha Vacuum valve
US20080002327A1 (en) * 2006-04-03 2008-01-03 Ground Co., Ltd. Earthing Device Which Needs Not Be Buried Under Ground
EP1841027A3 (en) * 2006-03-29 2013-04-24 Mitsubishi Materials Corporation Surge absorber

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3150974A1 (de) * 1980-09-06 1983-06-30 Calor-Emag Elektrizitäts-Aktiengesellschaft, 4030 Ratingen Vakuumschalter
JPS58186589U (ja) * 1982-06-08 1983-12-12 株式会社白山製作所 通信用ガス入放電管形避雷器

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1582330A (en) * 1919-05-17 1926-04-27 Leon S Brach Lightning-arrester construction
US3189777A (en) * 1961-06-19 1965-06-15 Westinghouse Electric Corp Low-pressure electric discharge lamp, and electrode assembly therefor, having martensitic stainless steel anode
US3679474A (en) * 1971-01-18 1972-07-25 Gen Electric Periodic electrode structure for vacuum gap devices

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3471734A (en) * 1967-05-19 1969-10-07 Gen Electric Periodic electrode structure for vacuum gap devices

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1582330A (en) * 1919-05-17 1926-04-27 Leon S Brach Lightning-arrester construction
US3189777A (en) * 1961-06-19 1965-06-15 Westinghouse Electric Corp Low-pressure electric discharge lamp, and electrode assembly therefor, having martensitic stainless steel anode
US3679474A (en) * 1971-01-18 1972-07-25 Gen Electric Periodic electrode structure for vacuum gap devices

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3825789A (en) * 1973-06-29 1974-07-23 Gen Electric Vacuum arc devices with hard, ductile, ferrous electrodes
US3851203A (en) * 1973-07-30 1974-11-26 Gen Electric Vacuum arc devices with improved arcing shields
US3969598A (en) * 1975-02-03 1976-07-13 General Electric Company Vacuum-type circuit interrupter with a plurality of sets of contacts in parallel
US4128748A (en) * 1976-07-21 1978-12-05 General Electric Company High-current vacuum switch with reduced contact erosion
US4063126A (en) * 1977-02-16 1977-12-13 General Electric Company Vacuum arc discharge device with tapered rod electrodes
JPS5441473A (en) * 1977-09-02 1979-04-02 Electric Power Res Inst High voltage two stage trigger type vacuum gap device
WO1990003657A1 (de) * 1988-09-22 1990-04-05 Siemens Aktiengesellschaft Vakuumschaltröhre, eine solche schaltröhre enthaltender lasttrennschalter und verfahren zum betrieb eines solchen lasttrennschalters
US5168139A (en) * 1988-09-22 1992-12-01 Siemens Aktiengesellschaft Load-break switch having a vacuum interrupter and method of operation
EP0924729A3 (en) * 1997-12-16 2000-05-10 Kabushiki Kaisha Toshiba Electrode arrangement of vacuum circuit breaker with magnetic member for longitudinal magnetization
EP1039495A3 (de) * 1999-03-23 2001-08-08 Siemens Aktiengesellschaft Verfahren zur Strombegrenzung in Niederspannungsnetzen, zugehörige Anordnung sowie spezielle Verwendung dieser Anordnung
US20020153353A1 (en) * 2001-04-19 2002-10-24 Mitsubishi Denki Kabushiki Kaisha Vacuum valve
EP1841027A3 (en) * 2006-03-29 2013-04-24 Mitsubishi Materials Corporation Surge absorber
US20080002327A1 (en) * 2006-04-03 2008-01-03 Ground Co., Ltd. Earthing Device Which Needs Not Be Buried Under Ground
US7652865B2 (en) * 2006-04-03 2010-01-26 Ground Co., Ltd. Earthing device which needs not be buried under ground

Also Published As

Publication number Publication date
DE2308913A1 (de) 1973-10-04
GB1401867A (en) 1975-08-06
JPS496435A (enrdf_load_stackoverflow) 1974-01-21
CA977407A (en) 1975-11-04
FR2176902A1 (enrdf_load_stackoverflow) 1973-11-02
FR2176902B1 (enrdf_load_stackoverflow) 1978-02-10

Similar Documents

Publication Publication Date Title
US3769538A (en) Vacuum arc devices with ferrous electrodes
US2975255A (en) Vacuum circuit interrupters
US5168139A (en) Load-break switch having a vacuum interrupter and method of operation
US3038980A (en) Vacuum-type circuit interrupter
US3825789A (en) Vacuum arc devices with hard, ductile, ferrous electrodes
US3798484A (en) Series multiple break vacuum arc discharge devices
US4471184A (en) Vacuum interrupter
US7662208B2 (en) Electrical contacts for vacuum circuit breakers and methods of manufacturing the same
US3140373A (en) Arc ionizable beryllium electrodes for vacuum arc devices
US3792214A (en) Vacuum interrupter for high voltage application
US3821505A (en) Vacuum type electric circuit interrupting devices
US3643047A (en) Series double break rod array vacuum switch
US4367382A (en) Vacuum circuit breaker
US3508021A (en) Vacuum switch
US3997748A (en) Vacuum interrupter with primary electrode surrounded by high dielectric strength shield
Cobine Research and development leading to high-power vacuum interrupters
US4553003A (en) Cup type vacuum interrupter contact
JP2011108380A (ja) 真空バルブ用電気接点およびそれを用いた真空遮断器
US3851203A (en) Vacuum arc devices with improved arcing shields
US3854068A (en) Shield structure for vacuum arc discharge devices
US3356893A (en) High power vacuum discharge device having a pair of interleaved multivaned arcing electrodes
Temborius et al. Switching behavior of different contact materials for vacuum interrupters under load switching conditions
US3612795A (en) Shielding arrangements for vacuum-type circuit interrupters of the two-contact type
Ballat et al. Insulation characteristics and welding behavior of vacuum switch contacts made from various CuCr alloys
US4760223A (en) Vacuum circuit interrupter