US3646296A - Circuit interrupter grid structure for oil-break circuit interrupter - Google Patents

Circuit interrupter grid structure for oil-break circuit interrupter Download PDF

Info

Publication number
US3646296A
US3646296A US703410A US3646296DA US3646296A US 3646296 A US3646296 A US 3646296A US 703410 A US703410 A US 703410A US 3646296D A US3646296D A US 3646296DA US 3646296 A US3646296 A US 3646296A
Authority
US
United States
Prior art keywords
combination
oil
venting
grid
molded
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
US703410A
Other languages
English (en)
Inventor
Robert L Hess
Gerald D Summers
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.)
Westinghouse Electric Corp
Original Assignee
Westinghouse Electric Corp
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 Westinghouse Electric Corp filed Critical Westinghouse Electric Corp
Application granted granted Critical
Publication of US3646296A publication Critical patent/US3646296A/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
    • H01H33/70—Switches with separate means for directing, obtaining, or increasing flow of arc-extinguishing fluid
    • H01H33/72—Switches with separate means for directing, obtaining, or increasing flow of arc-extinguishing fluid having stationary parts for directing the flow of arc-extinguishing fluid, e.g. arc-extinguishing chamber
    • H01H33/75—Liquid-break switches, e.g. oil-break

Definitions

  • An oil-type circuit breaker has three poles provided in a unitary tank structure, each pole comprising a pair of serially related grid structures.
  • the grid structures are constructed by nesting a plurality of plate elements, constituting vent passages and oil pockets, within an outer cylindrical glass-filament-wound shell.
  • the stationary contact assembly is so arranged as to have a lengthened finger, which serves as an arcing horn disposed adjacent side lateral vent openings.
  • vent openings are formed by molded vent elements of particular materials and having a splitter plate interposed f'therebetween. Additional oil pockets and a lower oil-pocket plug, having an entrance opening, assist in guiding the movable contact rod, and additionally providing considerable turbulence within the oil during the opening operation.
  • the dimensions have been reduced and the grid elements have been improved, with improved venting channels of constant cross-sectional area, and with oil pockets of such configuration and location, as to provide highly efficient oil grid units, and to enable the radially spaced disposition of six such units within a single tank, thereby permitting the three pole-units, for a three-phase con struction, to be disposed within a single unitary tank structure.
  • each of the six grid units comprises a nesting of several grid elements within an outer cylindrical glass-filament-wound shell, having an upper insert, which enables its ready assemblage to a threaded contact foot.
  • venting channels and suitably located oil pockets provided by elements of unique composition, a highly favorable arrangement, including gas evolution and oil turbulence, is achieved to result in a highly efficient grid unit of reduced dimensions.
  • the dimensions of all the elements are reduced and the structure thereby made more lightweight in construction.
  • vent channels having a splitter plate interposed therebetween to encourage arc looping into the vent channels and to prevent its physical ejec tion externally of the grid casing.
  • a general object of the present invention is, accordingly, to provide an improved oil-break grid structure for a circuit interrupter of highly efficient operation and of reduced dimen- SIOIIS.
  • Still a further object of the present invention is to provide an improved oil grid structure, in which a few of the several insulating elements are provided, such as by molding, from particular resinous materials.
  • Still a further object of the present invention is the provision of a low-cost, rapidly assembled grid structure, which is highly efficient in operation and of reduced dimensions.
  • FIG. I is a vertical sectional view taken through a three-pole oil-type circuit interrupter embodying the principles of the present invention, the contact structure being illustrated in the closed-circuit position;
  • FIG. 2 is a plan view, the line IIII of FIG. 1;
  • FIG. 3 is a considerably enlarged vertical sectional view taken through the interior of one of the oil grid units, the contact structure being illustrated in the closed-circuit position;
  • FIG. 3a is a fragmentary view, somewhat similar to that of FIG. 3, but illustrating the disposition of the several parts, and the arc location, during an intermediate part of the opening operation;
  • FIG. 4 is an end elevational view of the oil grid structure of FIG. 3;
  • FIG. 5 is an inverted plan view of the contact housing of FIG. 3, taken in the direction of the arrows V-V of FIG. 3;
  • FIG. 6 is a top plan view of one ofthe venting elements
  • FIG. 7 is an end elevational view of the venting element of FIG. 6;
  • FIGS. 8 and 9 are vertical sectional views taken through the bottom and top molded venting plates respectively;
  • FIG. 10 is a vertical sectional view taken through the lower insulating molded plug element of the oil grid.
  • FIG. 11 is a top plan view of the lower plug element of FIG. 10.
  • FIGS. 1 and 2 there is provided a threephase oil-type circuit interrupter l adaptable for intermediate voltage ratings, such as 34.5 kv., for example, and say, for example, having a current rating of l,200 amperes.
  • the three pole-units A, B and C are disposed within a single tank structure 2.
  • each of the oil grid units 4 is clamped to, and fixedly secured to, the lower ends 5 of the terminal bushing studs 6 extending through the upper cover 7 of the tank 2.
  • Current transformers 8 may surround the terminal bushings 9 beneath the cover 7 for relaying circuits.
  • each pole-unit A, B or C comprises a pair of serially related grid structures 4, which are electrically interconnected by conducting crossarms 11A, 11B, or 11C, which are reciprocally vertically moved, in an opening and closing direction, by lift rods 12A, 128 or 12C.
  • Three such lift rods 12A, 12B and 12C are provided and are mechanically interconnected to the linkage mechanism disposed at the upper end of the tank structure 2.
  • FIG. 3 more clearly illustrates the internal construction of the grid structure 4.
  • an outer cylindrical insulating shell 14 formed of a suitable insulating material, such as gIass-filament-filled epoxy resin, and having the several grid elements disposed therein, as more fully explained hereinafter.
  • a split casting 15, serving as a contact foot, is threaded, as
  • Each finger 21 is a Cupaloy, or copperchromium alloy forging fitted with an arc-resistant tungstensilver alloy tip 21a.
  • One of the fingers 24A is five-sixteenths inch longer than the other three, for example.
  • the long finger 24A is the last to separate with the moving contact 26, thus acting as an arc horn for protecting the other contact surfaces from burning.
  • All four fingers 21 are spring loaded, as at 27. to provide the proper contact pressure against the rod-type moving contact 26 and the stationary finger block 22 in the closed position, as shown in FIG. 3. The resulting rocker-type action of the four fingers 21 eliminates shunting of the four fingers 21 to the finger block 22.
  • the grid portion 4A is composed of a stack of insulating elements of various compositions housed within a 4-inch inside diameter, for example, glass-filament-wound shell 14 of the voltage rating considered.
  • the grid assembly is threaded onto the finger box 17 by means of an aluminum insert 1411, which is incorporated and interlocked in the shell 14 during the actual glass-filament-winding process.
  • a small bolt 28, threaded into a lug 29 on the finger box 17 is tightened against the machinedtop surface 146 of the tube 14 locking it in place.
  • the projection 30 of the arc-horn finger 24A down into the apertures 31, 32 in the top two fiber plates 33, 34 of the grid stack 4 make it necessary to mount these two plates 33, 34 on the finger box 17 with retaining screws 35.
  • the remainder of the stack elements are inserted directly into the glass-filamentwound shell 14, and mate with the top two fiber plates 33, 34 when the shell 14 is threaded onto the finger box 17.
  • the third and fifth plates 36, 37 in the grid are each 0.75-inch thick, for example, and injection molded of glass-reinforced Celcon" or Delrin.
  • Celcon and .Delrin are high molecular weight polyoxymethylene materials. They are both thermoplastic resins. Delrin” is commercially available from E. I. du Pont Company and Celcon” from the Celanese Corporation. For details of preparation of suitable polyoxymethylenes, reference may be had to U.S. Pat. No. 3,027,352 and U.S. Pat. No. 2,768,994.
  • a splitter made from one-fourth-inch thick, for example, fiber sheet, the group forms the vent channels 41, 42 for the grid 4.
  • Snouts or projections 36a, 37a on these three vent elements extend through a hole 44 bored into the sidewall of the giass-filamentwound tube 14.
  • This arrangement provides a positive alignment of the vent channels 41, 42 of the stack with the hole 44 in the shell 14.
  • Correct alignment of the vent plates 36, 37 and splitter plate 39 is further insured by two small bosses, on each of the molded vent plates 36, 37 that fit into punched holes provided in the splitter plate 39.
  • the channel is 0.5-inch high by 0.75-inch wide, for example, with a 0.06-inch radius at the comers X at the inside end, providing a desired flow area for gasses formed during arcing. From the arcing end X" to the exhaust end Y (FIG. 9) of the channels 41, 42, the corners blend from the 0.06-inch radius to a 0.34-inch radius, thereby maintaining the same cross-sectional vent area throughout the channels 41,42. The channel height at the exhaust end Y" is reduced to 0.34-inch high, for example, allowing for the small exit hole 44 in the filament-wound shell 14.
  • each vent plate 36, 37 is a large cavity, that forms a separate oil pocket when assembled in the filament-wound shell 14.
  • the sixth, seventh, ninth and th plates 46, 47, 49, 50 in the grid 4 are simple 0.25-inch thick punched round fiber plates, for example, with a 1.06-inch diameter clearance hole 53 in their center for the moving contact 26. These plates add strength to the inner construction of the interrupter 4 and form oil pockets 55, 56 with the plates above and below them. Variations in fiber thickness, which ultimately affect the grid stack height, are compensated for by substituting, or adding 0.l88-inch thick fiber plates of the same design for these plates. A dimensional check of the interrupter stack can be made before assembly in the shell 14.
  • the eighth element 48 is more a spacer than a plate. It is machined from polyvinyl chloride resin pipe to fit snugly within the filament-wound shell 14. Bounded by the above fiber plates 46, 47, it forms the largest oil pocket 55 in the interrupter 4.
  • the 11th, 12th and 13th plates 58-60 are, in essence, three cork-neoprene washers, that compress between the flat fiber plate 50 and the bottom plug 62 when the interrupter 4 is threaded onto the finger box 17.
  • the bottom plate 62 in the interrupter 4 is unique in that it is also injection-molded of glass-reinforced Celcon.” In its design are incorporated many functions. It serves as a plug for the open-ended filament-wound shell 14, seating on a chamfered shelf 14c, that is integrally wound into the shell 14.
  • In the center of the plug 62 is a tapered entrance hole 62b for the moving contact 26 that assures its proper entry and alignment.
  • An inner cavity 620 in the .Celcon plug 62 forms the lowermost oil pocket 56 in the grid stack 4.
  • the assembly of the interrupter grid 4 is somewhat in reverse order, than as described above. All of the plates are assembled in the filament-wound shell 14 from the threaded insert upper end, starting with the molded Celcon" bottom plug 62.
  • the simple design used in the construction of this interrupter 4 provides a unit that is easy to assemble, inspect and maintain.
  • the mechanical linkage disposed adjacent the upper end of the tank 2, causes downward opening movement of the three liftrods 12A, 12B and 12C.
  • This downward opening motion of the three lift-rods causes corresponding downward opening movement of the three conducting crossbars 11A, 11B and 11C.
  • the several, rod-shaped moving contacts 26 move downwardly away from the stationary contacts 24, and cause the establishment of arcs 25 between the arcing finger contacts 24A and the tip portions 26a of the moving contacts 26.
  • FIG. 3A illustrates more clearly the arc establishment, wherein the arc 25 is carried by the explosive action of the oil and vapor out through the lateral vent channels 41, 42 causing the are 25 to pass through the aperture 39a provided in the splitter plate 39.
  • This hole 39a in the splitter plate 36 stabilizes the arc position, and permits the two looped portions 25a, 25b of the are 25 to move somewhat laterally out of the vent channels 41, 42 to receive the full lateral thrust of the oil and gas flow externally of the grid unit 4.
  • the provision of the oil venting pockets 36b, 37b and 55 maintains a plentiful supply of oil 3 adjacent the path of movement of the moving contact 26, and causes the vaporization of the oil within these pockets. If the are 25 has not been interrupted by the time that it passes through the apertures 53 of the plates 49 and 50, it encounters an additional oil pocket 56 adjacent the lower end of the grid structure 4.
  • the operating mechanism linkage causes upward closing travel of the lift rods 12A, 12B and 12C. This causes corresponding upward movement of the conducting cross-arms 11A, 11B and 11C, thereby causing the several moving contacts 26 to come into closed contacting engagement with the stationary contact structures 24, thus completing the circuit through the interrupting device 1.
  • a liquid-break type of circuit interrupter including a tank structure, a grid unit having a relatively stationary contact disposed adjacent its upper end, a terminal bushing extending into said tank structure and supporting said grid unit adjacent its lower end, liquid disposed in said tank structure and submerging said grid unit, plate structure disposed interiorly within said grid structure, a funnel-shaped molded plug member of resinous material located at the lower end of said grid unit and having a reentrant wall portion to define a liquid pocket and a central opening therethrough, and a rod-shaped movable contact movable through said central opening into engagement with said relatively stationary contact during the closing operation.
  • the grid unit comprises a tube having a lower inclined supported shelf portion, and the funnel-shaped molded plug member having a radially outwardly extending beveled portion seating on the aforesaid shelf portion.
  • thermoplastic resinous material is a high molecular weight polyoxymethylene material.
  • a tank structure having a terminal bushing having a terminal stud passing therethrough and extending into said tank structure, a contact foot secured to the lower end of the terminal stud, a stationary contact housing secured to the lower side of the contact foot, an insulating interrupter shell secured to the stationary contact housing, a plurality of separate insulating elements nested within the insulating interrupter shell, at least one of the elements providing a lateral venting channel extending laterally out an opening in the sidewall of said shell, and the same cross-sectional venting area existing throughout the venting channel.
  • the resilient ringshaped means comprises one or more washer plates comprising neoprene material.
  • the plate structure comprises one or more molded members having integrally molded generally U-shaped vent-forming portions which extend out a-hole in an enclosing tube structure.
  • An oil grid unit comprising an outer tube having an opening through the sidewall thereof, spaced vent-forming molded members of thermoplastic material having generally U-shaped venting portions, an intervening splitter plate disposed between said molded members and extending through said hole, means for establishing an arc within sai grid unit, whereby the oil and gas is ejected out of the two venting channels, and the cross-sectional area of the venting channels being constant.

Landscapes

  • Breakers (AREA)
  • Arc-Extinguishing Devices That Are Switches (AREA)
US703410A 1968-02-06 1968-02-06 Circuit interrupter grid structure for oil-break circuit interrupter Expired - Lifetime US3646296A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US70341068A 1968-02-06 1968-02-06

Publications (1)

Publication Number Publication Date
US3646296A true US3646296A (en) 1972-02-29

Family

ID=24825272

Family Applications (1)

Application Number Title Priority Date Filing Date
US703410A Expired - Lifetime US3646296A (en) 1968-02-06 1968-02-06 Circuit interrupter grid structure for oil-break circuit interrupter

Country Status (3)

Country Link
US (1) US3646296A (enrdf_load_stackoverflow)
ES (1) ES362870A1 (enrdf_load_stackoverflow)
GB (1) GB1253253A (enrdf_load_stackoverflow)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5042146A (en) * 1990-02-06 1991-08-27 Watson Troy M Method and apparatus of making an electrical interconnection on a circuit board
US20190355534A1 (en) * 2015-08-07 2019-11-21 Supergrid Institute Mechanical cut-off apparatus for a high-voltage or very high-voltage electric circuit with splitting device

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2760033A (en) * 1952-11-19 1956-08-21 Westinghouse Electric Corp Circuit interrupter
DE1143891B (de) * 1959-08-28 1963-02-21 Continental Elektro Ind Ag Anordnung an Loeschkammern fuer Fluessigkeitsschalter mit Querbespuelung des gezogenen Lichtbogens
US3128360A (en) * 1960-01-14 1964-04-07 Ite Circuit Breaker Ltd Interrupter structure having splitter plates of malleable material
US3214550A (en) * 1962-05-02 1965-10-26 Westinghouse Electric Corp Circuit interrupters with crossbars captively related to piston structures
US3335245A (en) * 1966-01-12 1967-08-08 Ite Circuit Breaker Ltd Combined tank liner interphase barrier for oil circuit breakers
US3356811A (en) * 1965-01-15 1967-12-05 Westinghouse Electric Corp Oil-type circuit breakers having outer continuous insulating support tube and inner stacked insulating plates providing lateral vent openings
US3392248A (en) * 1965-03-12 1968-07-09 Ite Circuit Breaker Ltd Interrupter structure having contoured arc splitter plates and separately housed resistor contacts and resistor structure therefor

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2760033A (en) * 1952-11-19 1956-08-21 Westinghouse Electric Corp Circuit interrupter
DE1143891B (de) * 1959-08-28 1963-02-21 Continental Elektro Ind Ag Anordnung an Loeschkammern fuer Fluessigkeitsschalter mit Querbespuelung des gezogenen Lichtbogens
US3128360A (en) * 1960-01-14 1964-04-07 Ite Circuit Breaker Ltd Interrupter structure having splitter plates of malleable material
US3214550A (en) * 1962-05-02 1965-10-26 Westinghouse Electric Corp Circuit interrupters with crossbars captively related to piston structures
US3356811A (en) * 1965-01-15 1967-12-05 Westinghouse Electric Corp Oil-type circuit breakers having outer continuous insulating support tube and inner stacked insulating plates providing lateral vent openings
US3392248A (en) * 1965-03-12 1968-07-09 Ite Circuit Breaker Ltd Interrupter structure having contoured arc splitter plates and separately housed resistor contacts and resistor structure therefor
US3335245A (en) * 1966-01-12 1967-08-08 Ite Circuit Breaker Ltd Combined tank liner interphase barrier for oil circuit breakers

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
ITE Circuit Breaker Company Bulletin No. 2031A; March, 1960; *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5042146A (en) * 1990-02-06 1991-08-27 Watson Troy M Method and apparatus of making an electrical interconnection on a circuit board
US20190355534A1 (en) * 2015-08-07 2019-11-21 Supergrid Institute Mechanical cut-off apparatus for a high-voltage or very high-voltage electric circuit with splitting device
CN111599630A (zh) * 2015-08-07 2020-08-28 超级电力研究所有限公司 用于高压或极高压电气电路的机械断路器装置
US10763060B2 (en) * 2015-08-07 2020-09-01 Supergrid Institute Mechanical cut-off apparatus for a high-voltage or very high-voltage electric circuit with splitting device
CN111599630B (zh) * 2015-08-07 2022-08-16 超级电力研究所有限公司 用于高压或极高压电气电路的机械断路器装置

Also Published As

Publication number Publication date
GB1253253A (enrdf_load_stackoverflow) 1971-11-10
ES362870A1 (es) 1970-11-16

Similar Documents

Publication Publication Date Title
US9153399B2 (en) ARC baffling device
US2100753A (en) Circuit interrupter
US3845263A (en) Circuit breaker with spring charged operating mechanism
US3707612A (en) Circuit interrupter with improved molded insulating housing formed with vent passage means
US4570202A (en) Gas-insulated switchgear equipment
US3792213A (en) High-voltage circuit interrupter incorporating series vacuum interrupter elements
US3632926A (en) Current-limiting circuit breaker having arc extinguishing means which includes improved arc initiation and extinguishing chamber construction
US2561450A (en) Electric switch
US4525612A (en) Gas insulated switch
US3110791A (en) Circuit interrupter with pressure-generating and interrupting contacts in insulating interrupting tube
US3128360A (en) Interrupter structure having splitter plates of malleable material
US3646296A (en) Circuit interrupter grid structure for oil-break circuit interrupter
US3586804A (en) Disconnect switch
US3243559A (en) Electric switch with novel arc cooling means
US2316470A (en) Switch construction
US3243558A (en) High voltage three-phase circuit breaker module
US2429846A (en) Electric circuit interrupter
US4440996A (en) Dead tank gas-insulated puffer-type circuit interrupter having interrupting unit in insulated casing
US2629036A (en) Circuit breaker
US2824934A (en) Visible-blade arc-extinguishing disconnecting switch
US2671144A (en) Circuit interrupter
US2352984A (en) Circuit breaker
US3242291A (en) Gas-evolving arc-elongating highvoltage fuse
US2492726A (en) Electric switch
US3632932A (en) Current-limiting circuit breaker having a field strap assembly