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US2302592A - Alternating current electric circuit breaker of the gas blast type - Google Patents

Alternating current electric circuit breaker of the gas blast type Download PDF

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Publication number
US2302592A
US2302592A US388700A US38870041A US2302592A US 2302592 A US2302592 A US 2302592A US 388700 A US388700 A US 388700A US 38870041 A US38870041 A US 38870041A US 2302592 A US2302592 A US 2302592A
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US
United States
Prior art keywords
insulator
gas
arc
metal
breaker
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
US388700A
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English (en)
Inventor
Amer Donald Foster
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.)
A Reyrolle and Co Ltd
Original Assignee
A Reyrolle and Co Ltd
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 A Reyrolle and Co Ltd filed Critical A Reyrolle and Co Ltd
Application granted granted Critical
Publication of US2302592A publication Critical patent/US2302592A/en
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Expired - Lifetime legal-status Critical Current

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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
    • H01H33/70—Switches with separate means for directing, obtaining, or increasing flow of arc-extinguishing fluid
    • H01H33/7015—Switches with separate means for directing, obtaining, or increasing flow of arc-extinguishing fluid characterised by flow directing elements associated with contacts
    • H01H33/7038—Switches with separate means for directing, obtaining, or increasing flow of arc-extinguishing fluid characterised by flow directing elements associated with contacts characterised by a conducting tubular gas flow enhancing nozzle
    • 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
    • H01H33/53—Cases; Reservoirs, tanks, piping or valves, for arc-extinguishing fluid; Accessories therefor, e.g. safety arrangements, pressure relief devices
    • H01H33/58—Silencers for suppressing noise of switch operation

Definitions

  • This invention relates to A. C. electric circuitbreakers of the gas-blast type, that is to circuitbreakers having arc-control devices of the kind in which a blast of deionising gas is used. to assist in extinguishing the are formed between the circuit-breaker arcing contacts when the circuitbreaker is opened.
  • Such circuit-breakers may be of the lateral blast type, wherein the blast flows across and more or less perpendicular to the direct path between the circuit-breaker contacts and is discharged through a nozzle or vent on one side of such direct path, or of the axial blast type, wherein the blast flows along and more or less parallel to the direct path between the arcing contacts.
  • the present invention has for its primary object to provide an improved circuit-breaker of the gas-blast type which will operate more efiiciently than hitherto, both in respect of more satisfactory extinguishing of the arc and in respect of reduced risk of subsequent breakdown after the arc has been extinguished.
  • a more detailed object is to provide a mounting for the nozzle or vent wherein risk of breakdown between such nozzle or vent and the contacts is reduced to a minimum.
  • a further object is to ensure that the hot ionised gases discharged by the blast are adequately cooled and deionised before reaching the atmosphere.
  • Yet another object relates more particularly to lateral blast circuit-breakers.
  • the gas-blast tends to cause the arc to bow out into or through the nozzle, but diiiiculties would arise if the arc were allowed freely to bow out to a considerable length, especially when the circuit-breaker is enclosed in an earthed metal casing.
  • the arc energy would be large with consequent high back pressure, and since for a short time after the zero current period the dielectric strength of the arc is built up for a short distance near the arc roots, the arc would behave as an insulated conductor and would have considerable capacity to the contacts and to the earthed casing, with the result that restriking of the arc would be assisted owing to the uneven distribution of the voltage between the arc and the contacts.
  • Figure la is a continuation of Figure 1 showing the lower part of the cooling and deionising unit
  • Fig. lA' is a continuation view showing the right hand end of Fig. 1.
  • Figure 2 is a plan view of the cooling and deionising unit
  • Figure 4 is a fragmentary vertical section on a larger scale on the line 4-4 of Figure 2,
  • 5 and 6 are vertical sections at right angles showing an alternative construction of lateral blast circuit-breakers
  • Figures 7 and 8 are vertical sections respectively of two further constructions.
  • the gas-blast may be generated or supplemented in the manner known in itself by the action of the arc on suitable gasproducing solid material disposed within the insulator A adjacent to the contacts, it is preferably produced by the introduction into the insulator of gas under pressure from an external source, such as a storage reservoir C
  • the moving contact member C may be actuated by suitable actuating mechanism disposed for example in the end casing C or alternatively the gas pressure derived from the reservoir C may itself be utilised for this purpose, the moving contact member being provided with a piston C on which the gas pressure may act.
  • the arrangement is preferably such that the moving contact moves away from the fixed contact only through a predetermined short distance, since (as is known in itself) more efficient rupturing of the arc by the gas-blast is obtained with only a relatively short gap between the main contacts, the gap being such that its breakdown voltage is greater than the normal working voltage of the system but les than the surge voltage which would be produced by extinction of the are at a point in the A. C. cycle away from the normal current zero.
  • the fixed contact B is provided with an arcing tip B on one side adjacent to the discharge vent.
  • a second fixed arcing tip C at the appropriate arcing distance from the fixed arcing tip B the moving contact C being in the form of a bridging contact between the two arcing tips and remaining in engagement with the second arcing tip C after separation from the fixed contact B.
  • the arc will be initially drawn out between the moving contact C and the fixed arcing tip B and after a predetermined movement will be transferred to the two arcing tips B C
  • the discharge through the lateral branch D, D is effected through a restricted aperture preferably in the form of a nozzle, and in order to reduce risk of restriking of the are between the nozzle and the contacts.
  • the nozzle is supported by an insulator so shaped and mounted as to provide a surface leakage path, which is long in comparison with the direct breakdown path across the ga between the nozzle and the contacts and is shielded from the radiant heat of the arc.
  • the insulator supporting the nozzle is spaced apart from the insulatin wall D of the lateral branch to provide the long leakage path shielded from direct heat radiation from the arc.
  • an insulating washer F is provided between the unit casing E and the flange F and the bolts F by which such casing is attached to the flange are shrouded in insulation F
  • the unit casing E is provided with one or more discharge outlets E and the short cylindrical portion of the flanged ring F extends so close to the discharge outlet or outlets that substantially the whole of the gases escaping through the outlets will come into contact with the earthed metal before doing so.
  • the space between the two perforated conical walls is filled with metal packing (not shown) which may be in the form of a large number: of short lengths of metal tubing, the metal used preferably being copper or some other metal having high heat and electrical conductivity.
  • the conical upper end of the insulator G is Y spaced apart from the insulating wall D of the the contac s by the provision of the separate insulator G giving the long leakage path.
  • a large part of such path moreover lies in the annula soace G between the insulator G and the insulating wall D, such space being well shielded by the insulator G from the heating effects of the arc and from any tendency to accumulate ionised gases, so that the air in such space is adequately protected against any deterioration in its dielectric properties.
  • the aperture P in the metal disc P must be of sufficient size to prevent the are from striking on to the edges of the aperture instead of passing through to the auxiliary electrode, whilst yet being small enough to give the desired throttling effect to the gas-blast.
  • This modification has the advantage of reducing the burning effect on the nozzle.
  • a cooling device comprising a space between two perforated conwithin the insulator G.
  • a second cooling device may also be provided in the path of the a c gases, b. device being in the form of a metal of ex ensive surface area within the insulator, or (as shown) of a second space filled with metal. packing for example between a pair of perforated plates T. T extending across the open end of the insulator G.
  • the in vcnton is also applicable to a circuit-breaker of the axial-blast type, wherein the circuit-breaker contacts in their open position lie one on either of the nozzle or vent so that the are exthrough the nozzle vent and the gasblast flows therethrough around the arc and in the direction of the length thereof.
  • the circuit-breaker fixed contact Y is mounted on a spider Y within a generally cylindrical metal wall which may be of metal or of insulating material.
  • a generally cylindrical metal wall which may be of metal or of insulating material.
  • Such cylindrical wall Y also carries, adjacent to the fixed contact Y a hollow insulator Z which extends for a considerable distance away from the fixed contact with its exterior surface Z spaced apart from the cylindrical wall Y exc pt at the point of support.
  • This insulator Z carries, at the end remote from the fixed contact an apertured member Z constituting the nozzle or vent.
  • the aperture in such member is divergent towards the fixed contact Y and the interior surface of the insulator Z is shaped to conform to the divergent nozzle shape of the aperture.
  • the apertured member Z may be made of metal or of insulating material.
  • the moving contact of the circuit-breakor is in the form of a rod Y normally extending through a nozzle Z into engagement with the fixed contact Y but withdrawable longitudinally to open the circuit-breaker.
  • Gas under pressure is introduced into the space around the moving contact rod Y when it is desired to open the circuit-breaker. and such gas pressure may itself be used to effect movement of the rod. or alternatively the rod may be mechanically operated, the gas then serving solely to provide the gas-blast.
  • the outer surface Z of the insulator Z may be smooth or, as shown, may be provided with circumferential grooves or may be otherwise shaped to afford a long surface leakage path within a relative short length. It will be appreciated that similar grooves or their equivalent may be provided on the outer surface of the insulator C- in the arrangements of Figures 1 to 8.
  • An A. C. electric circuit-breaker comprising in combina ion with the circuit-breaker arcing contacts, for a source of gas under pressure, means for directing a blast of de-ionising gas derived from such source against the are formed on opening of the circuit-breaker to assist in exwhich the gas-blast is discharged, an insulator for supporting the anertured member, a wall surrounding such insulator, and means whereby the said insulator is so spaced apart from the surrounding wall as to form a pocket interrupting what would otherwise be a short surface leakage pa h forming part of a possible breakdown path between the contacts, such pocket providing additional surface leakage path which is long in comparison with the direct breakdown between. the contacts, is shielded from the radiant heat of the arc and is supplied with clean gas from the source.
  • An A. C. electric circuit-breaker comprising in combination with the circuit-breaker arcing contacts, means for directing a blast of deio-nising gas against the are formed when the contacts separate to assist in extinguishing the arc, an insulating wall surrounding the circuitbreaker contacts and having an open-ended lateral branch adjacent to such contacts, a discharge nozzle for the gas-blast separate from the contacts and located in such lateral branch on one side of the direct path between the contacts, and an insulator for supporting the nozzle projecting through the open end of the lateral branch and carried thereby in the neighbourhood of such open end so that the annular space between such insulator and the lateral branch affords a surface leakage path between the nozale and the contacts, which is long in comparison with the direct breakdown path across the gap between the nozzle and the contacts and is shielded from direct heat radiation from the are.
  • An A. C. electric circuit-breaker comprising in combination with the circuit-breaker arcing contacts, means for directing a blast of deionizing gas against the are formed when the contacts separate to assist in extinguishing the arc, a member located on one side of the direct path between the arcing contacts and having a restricted aperture through which the gas blast is discharged laterally with respect to such path, and an auxiliary electrode disposed in such a position as to lie in the path of the arc loop when bowed out through the restricted aperture by the gas-blast with its length extending along the end of the arc loop.
  • auxiliary electrode is in the form of a bar of such cross-section as to offer little obstruction to the flow of the gas past its sides.
  • An A. C. electric circuit-breaker as claimed in claim 7. in which the apertured member is made of insulating material and its aperture is divergent in the direction of gas flow and terminates in a metal ring carrying the auxiliary electrode.
  • auxiliary electrode in the form of a bar extending across the insulator with its length substantially parallel to the direct path between the circuit-breaker arcing contacts, the electrode being located in such a position as to lie in the path of the arc loop when bowed out through the nozzle of the gas blast.
  • a cooling and deionising unit for the discharged arc gases comprising a casing adapted to be secured to the circuit-breaker casing and having a discharge outlet for the gases through its wall, a hollow insulator within the casing having at one end a res l'icted aperture through which th gases are discharged from the circuit-breaker into the insulator, means whereby the gases are caused to traverse a circuitous path from the restricted aperture through the insulator to the discharge outlet, and earthed metal with which the gases are brought into contact before escaping through i the discharge outlet.

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  • Circuit Breakers (AREA)
US388700A 1940-04-15 1941-04-15 Alternating current electric circuit breaker of the gas blast type Expired - Lifetime US2302592A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB266747X 1940-04-15

Publications (1)

Publication Number Publication Date
US2302592A true US2302592A (en) 1942-11-17

Family

ID=10247395

Family Applications (1)

Application Number Title Priority Date Filing Date
US388700A Expired - Lifetime US2302592A (en) 1940-04-15 1941-04-15 Alternating current electric circuit breaker of the gas blast type

Country Status (6)

Country Link
US (1) US2302592A (de)
BE (2) BE467248A (de)
CH (2) CH271230A (de)
FR (2) FR927761A (de)
GB (3) GB541237A (de)
NL (2) NL109990C (de)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2481996A (en) * 1944-04-22 1949-09-13 Ferguson Pailin Ltd Air blast circuit breaker
US2599848A (en) * 1942-05-30 1952-06-10 Latour Andre Spark arrester for pressure gas switches
US2987596A (en) * 1958-12-06 1961-06-06 Asea Ab Scavenging means for air blast circuit breaker
US3617667A (en) * 1970-01-27 1971-11-02 Gen Electric Gas-blast circuit breaker with noise-reducing exhaust muffler assembly
US3649791A (en) * 1969-07-02 1972-03-14 Bbc Brown Boveri & Cie Arc chute for electrical switch apparatus

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB979783A (en) * 1960-04-29 1965-01-06 Reyrolle A & Co Ltd Improvements relating to high-voltage electric circuit-breakers of the gas-blast type
CH591756A5 (de) * 1975-06-18 1977-09-30 Bbc Brown Boveri & Cie
DE4333277C2 (de) * 1993-09-24 1995-07-06 Siemens Ag Hochspannungs-Leistungsschalter mit einer Kühleinrichtung zur Kühlung des Löschgases
DE19517615A1 (de) * 1995-05-13 1996-11-14 Abb Research Ltd Leistungsschalter

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2599848A (en) * 1942-05-30 1952-06-10 Latour Andre Spark arrester for pressure gas switches
US2481996A (en) * 1944-04-22 1949-09-13 Ferguson Pailin Ltd Air blast circuit breaker
US2987596A (en) * 1958-12-06 1961-06-06 Asea Ab Scavenging means for air blast circuit breaker
US3649791A (en) * 1969-07-02 1972-03-14 Bbc Brown Boveri & Cie Arc chute for electrical switch apparatus
US3617667A (en) * 1970-01-27 1971-11-02 Gen Electric Gas-blast circuit breaker with noise-reducing exhaust muffler assembly

Also Published As

Publication number Publication date
FR927761A (fr) 1947-11-10
CH266747A (fr) 1950-02-15
NL208615A (de)
NL109990C (de)
FR927760A (fr) 1947-11-10
GB541237A (en) 1941-11-19
GB541235A (en) 1941-11-19
CH271230A (fr) 1950-10-15
BE467249A (de)
GB541236A (en) 1941-11-19
BE467248A (de)

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