High-voltage switches with arc preventing or extinguishing devic – Arc preventing or extinguishing devices – Housing structure
Reexamination Certificate
1999-08-03
2001-02-13
Donovan, Lincoln (Department: 2832)
High-voltage switches with arc preventing or extinguishing devic
Arc preventing or extinguishing devices
Housing structure
C335S008000, C335S202000, C218S035000
Reexamination Certificate
active
06188036
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates generally to molded case circuit breakers. More specifically, the present invention relates a bottom vented circuit breaker capable of top down assembly onto equipment.
Conventional circuit breakers include a breaker casing with one or more pairs of separable contacts disposed therein. Typically, each pole or phase of the breaker employs a single contact pair comprising one fixed and one movable contact. The fixed contact is electrically connected to a breaker connection lug extending within an access opening formed on the line side of the case. The movable contact is electrically connected to a breaker connection lug extending within an access opening formed on the load side of the case. The breaker connection lugs are electrically connected to equipment connection lugs extending within the access openings and forming part of the protected circuit. The access openings allow the assembled circuit breaker to be installed in a top-down manner, onto the equipment connection lugs, with the equipment connection lugs passing through the access openings as the breaker is lowered onto the equipment.
In all circuit breakers, the separation of the breaker contacts due to a short circuit causes an electrical arc to form between the separating contacts. The arc causes the formation of relatively high-pressure gases as well as ionization of air molecules within the circuit breaker. These high-pressure gases can cause damage to the breaker casing. The gases, therefore, must be vented from the circuit breaker enclosure. In addition, a phase-to-phase fault can occur if the arc gases from different phases are allowed to mix, and a phase-to-ground fault can occur if the gases contact the grounded enclosure. To avoid a phase-to-phase or phase-to-ground fault, gases vented from different phases must be kept separate from each other and away from the grounded enclosure until the ionization has dissipated.
In a conventional circuit breaker, when an overcurrent condition is present in the protected circuit, the movable contact moves upward under the force of an operating mechanism mechanically attached thereto. This action generates arc gases above the fixed contact and its associated breaker connection lug. These gases are propelled towards the top corner of the breaker. Thus, the breaker case is designed with an arc gas vent located near the top corner, to vent the arc gases to atmosphere. Typically, the arc gas vent is located on the line side of the breaker case, above the breaker connection lug. Because the arc gas vent is located near the top of the case, above the breaker connection lug, there is no interference between the arc gas vent and the access opening, which is located beneath the breaker connection lug.
However, many modern molded case circuit breakers employ a contact arrangement where arc gases are frowned beneath the equipment and breaker connection lugs. A rotary contact arrangement is an example of such a contact arrangement. In rotary contact breakers, each pole or phase employs two sets of contacts: two fixed contacts that are fixed relative to the breaker case, and two movable contacts that rotate about a common axis generally perpendicular to the current path from the line side to the load side of the circuit breaker. When the movable and fixed contacts separate, the load-side movable contact moves downward, away from the load-side fixed contact. This action generates arc gases beneath the load-side lugs, and propels the gases towards the bottom corner of the breaker casing. Thus, it is desirable for the arc gas vent to be located at the bottom of the load side of the breaker casing. Unfortunately, such a location would interfere with the access openings and, therefore, the ability to install the breaker in a top-down manner.
BRIEF SUMMARY OF THE INVENTION
In an exemplary embodiment of the invention, a bottom vented circuit breaker capable of top-down assembly onto equipment includes a circuit breaker cassette including a pair of separable contacts, wherein one of the pair of separable contacts is electrically connected to a breaker connection lug. An equipment connection lug of a first width extends from a protected circuit for electrically connecting to the breaker connection lug. A molded base comprises a bottom wall and side walls forming an interior cavity adapted to receive the breaker cassette. A pair of arc gas ducts are attached to the molded base below the breaker connection lug for receiving arc gas generated by the separable contacts. The first and second arc gas ducts are substantially parallel to each other and are separated by a predetermined distance greater than the predetermined width of the equipment connection lug for allowing the equipment connection lug to pass therebetween.
REFERENCES:
patent: D. 367265 (1996-02-01), Yamagata et al.
patent: 2340682 (1944-02-01), Powell
patent: 2719203 (1955-09-01), Gelzheiser et al.
patent: 2937254 (1960-05-01), Ericson
patent: 3158717 (1964-11-01), Jencks et al.
patent: 3162739 (1964-12-01), Klein et al.
patent: 3197582 (1965-07-01), Norden
patent: 3307002 (1967-02-01), Cooper
patent: 3328553 (1967-06-01), Gryctko
patent: 3517356 (1970-06-01), Hanafusa
patent: 3631369 (1971-12-01), Menocal
patent: 3803455 (1974-04-01), Willard
patent: 3883781 (1975-05-01), Cotton
patent: 4129762 (1978-12-01), Bruchet
patent: 4144513 (1979-03-01), Shafer et al.
patent: 4158119 (1979-06-01), Krakik
patent: 4165453 (1979-08-01), Hennemann
patent: 4166988 (1979-09-01), Ciarcia et al.
patent: 4220934 (1980-09-01), Wafer et al.
patent: 4255732 (1981-03-01), Wafer et al.
patent: 4259651 (1981-03-01), Yamat
patent: 4263492 (1981-04-01), Maier et al.
patent: 4276527 (1981-06-01), Gerbert-Gaillard et al.
patent: 4297663 (1981-10-01), Seymour et al.
patent: 4301342 (1981-11-01), Castonguay et al.
patent: 4360852 (1982-11-01), Gilmore
patent: 4368444 (1983-01-01), Preuss et al.
patent: 4375021 (1983-02-01), Pardini et al.
patent: 4375022 (1983-02-01), Daussin et al.
patent: 4376270 (1983-03-01), Staffen
patent: 4383146 (1983-05-01), Bur
patent: 4392036 (1983-07-01), Troebel et al.
patent: 4393283 (1983-07-01), Masuda
patent: 4401872 (1983-08-01), Boichot-Castagne et al.
patent: 4409573 (1983-10-01), DiMarco et al.
patent: 4435690 (1984-03-01), Link et al.
patent: 4467297 (1984-08-01), Boichot-Castragne et al.
patent: 4468645 (1984-08-01), Gerbert-Gaillard et al.
patent: 4470027 (1984-09-01), Link et al.
patent: 4479143 (1984-10-01), Watanabe et al.
patent: 4488133 (1984-12-01), McClellan et al.
patent: 4492941 (1985-01-01), Nagel
patent: 4541032 (1985-09-01), Schwab
patent: 4546224 (1985-10-01), Mostosi
patent: 4550360 (1985-10-01), Dougherty
patent: 4562419 (1985-12-01), Preuss et al.
patent: 4589052 (1986-05-01), Dougherty
patent: 4595812 (1986-06-01), Tamaru et al.
patent: 4611187 (1986-09-01), Banfi
patent: 4612430 (1986-09-01), Sloan et al.
patent: 4616198 (1986-10-01), Padini
patent: 4622444 (1986-11-01), Kandatsu et al.
patent: 4631376 (1986-12-01), Leone
patent: 4631625 (1986-12-01), Alexander et al.
patent: 4639564 (1987-01-01), Grunert et al.
patent: 4642431 (1987-02-01), Tedesco et al.
patent: 4644438 (1987-02-01), Puccinelli et al.
patent: 4649247 (1987-03-01), Preuss et al.
patent: 4650940 (1987-03-01), Grunert et al.
patent: 4658322 (1987-04-01), Rivera
patent: 4672501 (1987-06-01), Bilac et al.
patent: 4675481 (1987-06-01), Markowski et al.
patent: 4682264 (1987-07-01), Demeyer
patent: 4689712 (1987-08-01), Demeyer
patent: 4694373 (1987-09-01), Demeyer
patent: 4710845 (1987-12-01), Demeyer
patent: 4717985 (1988-01-01), Demeyer
patent: 4733211 (1988-03-01), Castonguay et al.
patent: 4733321 (1988-03-01), Lindeperg
patent: 4764650 (1988-08-01), Bur et al.
patent: 4768007 (1988-08-01), Mertz et al.
patent: 4780786 (1988-10-01), Weynachter et al.
patent: 4831221 (1989-05-01), Yu et al.
patent: 4870531 (1989-09-01), Danek
patent: 4883931 (1989-11-01), Batteux et al.
patent: 4884047 (1989-11-01), Baginski et al.
patent: 4884164 (1989-11-01), Dziura et al.
patent: 4900882 (1990-
Cantor & Colburn LLP
Donovan Lincoln
General Electric Company
Horton Carl B.
LandOfFree
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