US3257533A - Fluid-blast circuit interrupters with two selectively-operated fluid-blast sources - Google Patents

Fluid-blast circuit interrupters with two selectively-operated fluid-blast sources Download PDF

Info

Publication number
US3257533A
US3257533A US452451A US45245165A US3257533A US 3257533 A US3257533 A US 3257533A US 452451 A US452451 A US 452451A US 45245165 A US45245165 A US 45245165A US 3257533 A US3257533 A US 3257533A
Authority
US
United States
Prior art keywords
blast
puffer
fluid
piston
valve
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
US452451A
Other languages
English (en)
Inventor
Winthrop M Leeds
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.)
CBS 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
Priority to US452451A priority Critical patent/US3257533A/en
Priority to DEW40928A priority patent/DE1229621B/de
Priority to CH295766A priority patent/CH464317A/de
Application granted granted Critical
Publication of US3257533A publication Critical patent/US3257533A/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
    • H01H33/7007—Switches with separate means for directing, obtaining, or increasing flow of arc-extinguishing fluid wherein the flow is a function of the current being interrupted

Definitions

  • This invention relates to circuit interrupters in general, and, more particularly, to circuit interrupters adaptable for interrupting medium-value and also relatively highpower circuits.
  • a general object of the present invention is to provide a highly effective and economical circuit interrupter suitable for the interruption of currents over a wide range of values.
  • a more specific object of the present invention is to provide an improved circuit interrupter of the puffer type, that is one injecting a quantity of arc-extinguishing gas into the contact structure by the operation of a piston structure; and preferably, supplementary means are additionally provided, selectively operated only during highcurrent interruptions, to force the injection of a liquefied gas into the arc region to assist in the interruption of highamperage fault currents.
  • circuit interrupter Another form of circuit interrupter, not using a puffer, which has been tested successfully interrupting over 40,000 amperes is a liquid sulfur-hcxafluoride (SP injector type, such as set forth in United States patent application filed September 13, 1957, Serial No. 683,760, now U.S. Patent 3,150,245 issued September 22, 1964 to Winthrop M. Leeds and Benjamin P. Baker, and assigned to the assignee of the instant application.
  • SP injector type such as set forth in United States patent application filed September 13, 1957, Serial No. 683,760, now U.S. Patent 3,150,245 issued September 22, 1964 to Winthrop M. Leeds and Benjamin P. Baker, and assigned to the assignee of the instant application.
  • this latter-mentioned circuit interrupter requires a high-cost compressor to take the low-pressure exhaust gas and recompress it into a liquid, and force it back into the accumulator.
  • a liquefied gas such as liquefied sulfur hexafluoride (SP gas
  • the circuit interrupter described in this invention shows two sources of gas blast to accomplish arc quenching.
  • One of these, for instance a puffer piston provides gas flow, preferably of SP suflicient to extinguish arcs in a range up to moderate current values of several thousand amperes.
  • a second source consisting of a reservoir containing fluid under high pressure in either the gaseous or liquid state, is selectively, controlled to come into action only when high currents above the range handled by the first source are to be interrupted.
  • Ruppel Patent Re. 21,125 broadly covers the above-described selective action interrupter.
  • the Ruppel structure, and other devices providing interrupting action initiated directly by overload current magnitude 'sutfer from the disadvantage that the high pressure blast is released whenever high overload current flows through the breaker regardless of whether or not the protective system has called for this particular breaker to be tripped.
  • My invention specifically avoids this undesirable situation by using a current-responsive element which does not produce a gas blast directly as by opening a valve, but rather sets up conditions under overload that will cause the high pressure fluid blast to be activated if and only if the breaker is actually tripped.
  • the construction shown involves current-initiated magnetic means for aligning a cam-operating surface with the cam line of action so that the opening movement of the breaker will operate the auxiliary blast valve on high current'overload conditions only. If the breaker is not tripped, no blast occurs even though high current actuates the cam alignment device.
  • FIG. 1 is a side elevational view of a circuit interrupter embodying features of the present invention
  • FIG. 2 is a longitudinal vertical sectional view taken through the tank structure of the circuit interrupter of FIG. 1 with the contact structure illustrated at an intermediate point in the opening operation, the putter structure shown rendered inoperable, and the liquefied gas injector being illustrated in its operable position;
  • FIG. 3 is a fragmentary sectional view taken substantially along the line IIIIII of FIG. 2; 1
  • FIG. 4 is an end elevational view of the circuit interrupter
  • FIG. 5 illustrates diagrammatically a radial type distribution system
  • FIG. 6 illustrates a modified type circuit interrupting arrangement
  • the reference numeral 1 generally designates a circuit interrupter particularly adaptable for interrupting a wide range of currents.
  • the circuit interrupter 1 generally comprises a tank structure 2 into which downwardly extend a pair of terminal bushings 3, 4.
  • the lower ends of the downwardly-extending terminal bushings 3, 4 support, in a fixed position, an interrupting assembly generally designated by the reference numeral 5.
  • the interrupting assembly 5 generally includes a perforated tubular movable contact 6 cooperable with a relatively stationary contact structure 7 comprising a plurality of finger contacts 8. As shown more clearly in FIG. 3, the finger contacts 8 are circumferentially disposed and engage the outer surface of the movable contact 6 in the closed-circuit position.
  • the movable contact 6 is secured to an operating rod 9 fixedly secured to a yoke member 10 of generally T-shaped configuration.
  • a yoke member 10 of generally T-shaped configuration.
  • a pair of insulating operating rods 12, 13 which abut at their right-hand ends a movable piston 14, operable within a piston cylinder 15 secured to the lower extremity 4a of the right-hand terminal bushing structure 4.
  • the movable contact structure is biased in a leftward opening direction by a contact accelerating spring 17.
  • a contact accelerating spring 17 To effect rightward closing movement of the movable contact structure 16 and consequent compression of the contact accelerating spring 17, there is provided an insulating operating rod 18 pivotally connected, as at 19, to a lower portion 20 of the yoke member 10.
  • the insulating operating rod 18 is pivotally connected, as at 21, to a rotatable crank-arm 22 keyed to an operating shaft 23, which passes through a sealed opening provided in a depending operating crank housing 24 associated with the tank structure 2.
  • the seal provided along the operating shaft 23 may be of the type set forth in United States Patent 2,889,434 issued June 2, 1959, to Harry I. Lingal, and assigned to the assignee of the instant application.
  • crank-arm 22 clockwise rotative movement of the crank-arm 22, as effected by an external operating mechanism, not shown, providing motive power through the operating shaft 23, will effect rightward closing movement of the movable contact structure 16 effecting thereby contact closing engagement between the movable tubular contact 6 and the relatively stationary contact structure 7 compressing the accelerating spring 17 and driving the puffer piston 14 toward the right, meanwhile effecting compression of the piston driving spring 25.
  • the breaker will then be in the closed-circuit position and is preferably latched in this position by the externally-situated operating mechanism.
  • the foregoing interrupting structure utilizing the puffer piston 14 is suitable for moderate value currents, say up to 10,000 amperes. However, at infrequent intervals, there occurs the existence of a heavy short-circuit current on the line, and fault currents over 10,000 amperes may be encountered. Thus, currents for high interrupting power, say above 20,000 amperes, may come into existence. To provide a puffer action which would be adequate to effect the interruption of these high-amperage currents would require excessive spring pressure for the piston driving spring 25. It is, therefore, an additional purpose of the present invention to provide a supplementary interrupting device 33 comprising a quantity of liquefied gas under pressure.
  • SP gas sulfur hexafluoride
  • supplementary means consisting preferably of liquefied sulfur hexafiuoride (SP gas is contained within a pressure bottle 35 disposed externally of the tank structure 2 and connected therewith by means of an insulating conduit 36.
  • a piston 37 disposed withinn-the pressurized bottle 35 is a piston 37 forced downwardly by nitrogen (N gas under pressure, say of the order of 800 to 1000 psi.
  • nitrogen nitrogen gas under pressure, say of the order of 800 to 1000 psi.
  • the liquid SP accumulator 35 with nitrogen above the piston separator compressed to about 800 p.s.i. (well above the SP vapor pressure to prevent vapor lock) would be located outside the breaker tank, as shown in FIGS. 1 and .4 to make the pressure gauge 33 and liquid-level indicator 39 visible.
  • the refilling plug 40 would be readily accessible.
  • a split magnetic ring 41 having associated therewith an armature 42.
  • the armature 42 is pivotally connected, as at 43, to a cam sleeve 44, which is biased by a helical spring, not shown, in a counterclockwise direction, as viewed in FIG. 3.
  • a cam lug 45 which, at times, makes abutting engagement with a valve cam follower 46, constituting one end of a valve actuating lever 47.
  • the armature 42 which causes the cam lug 45 to align with the cam follower 46, is so arranged as to be attracted and operable when current magnitudes, say of 10,000 amperes or over, flow through the contact structure 6, 7.
  • current magnitudes say of 10,000 amperes or over
  • the passage of current through the relatively stationary contact structure 7 will cause an encompassing magnetic flux to flow through the split magnetic ring 41.
  • the armature 4-2 Due to the air gap at 53, the armature 4-2 will be attracted, and will cause rotation of the cam sleeve 44 into an aligned position so that the cam lug 45 and valve cam follower 46 will make abutting engagement.
  • Puffer-type circuit interrupters utilizing sulfur-hexafiuoride are self-contained, that is, contain no compressor and high-pressure reservoir, and therefore are preferred as economical design for moderate power highvoltage breakers.
  • SP gas sulfur-hexafiuoride
  • puffer breakers require unreasonably high operating forces.
  • Another form of interrupter', not utilizing a puffer, which has been tested successfully interrupting over 40,000 amperes is a liquid SP injector type. However, this requires a high-cost compressor to take the low-pressure exhaust gas and recompress it into a liquid and force it back into the accumulator.
  • the present invention is particularly concerned with a puffer-type breaker for normal load-switching duty, which is provided with a liquid sulfur-'hexafluoride SP6 accumulator tank and a valve arrangement 54, whereby liquid SP is injected into the interrupting chamber 30 only when short-circuit current flows through the breaker contacts 6, 7 during a tripping operation. Since short-circuit conditions only occur at rare intervals, the amount of liquid SP stored is sufficient for many'years service, and it may be replenished as needed at normal maintenance periods.
  • the interrupting device 1 illustrated in FIG. 2 shows an embodiment of the invention in which the interrupter assemblage 5 is suspended from a pair of bushing terminals 3, 4 inside a grounded steel tank 2.
  • An insulating operating rod 18 is used to close the breaker by moving a tubular moving contact 6 into contacting engagement with a stationary finger cluster 7.
  • an accelerating spring .17 at the left-hand end of the assembly 5 is compressed, while on the right the puffer piston 14 is moved back compressing its driving spring 25.
  • the accelerating spring 17 drives the moving contact 6 to the left, and an are 26 appears at the separating contacts 6, 7.
  • the puffer piston 14 is also driven to the left, displacing SP gas through the check valve 29 and deionizing the arc 26,.which has moved to the arcing horn 27 and the inside 28 of the tubular moving contact 6.
  • the gas exhausts to a chamber 56 on the left terminal 3, then passes up the hollow conductor 3a to the bushing cap 3b, where it is filtered and return to the tank 2.
  • This filtering feature is set forth and claimed in United States patent application field March 217, 1961, Serial No. 98,632, now US. Patent 3,214,553, issued October 26, 1965, to Winthrop M. Leeds, and assigned to the assignee of the instant application.
  • the liquid SP accumulator 3 5 with nitrogen (N gas, above a piston separator 37, compressed to about800 p.s.i. (well above the SP vapor pressure to prevent vapor lock) would actually belocated outside the breaker tank 2, as shown in FIG. 1, to make the pressure gauge 38,
  • liquid-level indicator 39 and refilling plug 40 accessible.
  • a strong glass-reinforced insulating tube 36 would bring the liquid SP to the cam-operated valve 54 on the interrupter assembly 5.
  • the cam is attached to a cylindrical sleeve 44 free to rotate about operating rod 12, but retained lengthwise to move with the piston-retrieving operating rod 12.
  • a helical spring (not shown) keeps the cam 45 normally at such an angular position that reciprocating movement of the operating rod 12 will not operate the valve .54.
  • a split ring 41 of magnetic material surrounds the stationary finger cluster 7. When current above a predetermined value, say 10,000 amperes, flows through the contacts 6, 7, the flux across the air gap 53 pulls the armature 42 down.
  • the armature 42 is coupled to the cam sleeve 44 so that it will rotate the cam lug 45 in line with the follower 46 attached to the liquid SP valve 54 and still not impede longitudinal movement of the operating rod 12 and the cam sleeve 44,
  • the cam 45 becomes magnetically positioned so' that, as the contacts are opened, the cam follower 46 is actuated, opening the valve 54 momentarily to admit a quantity of liquid SP into the mixing chamber 30. Vaporization of this liquefied SP produces sufiicient gas pressure and flow that even high-current arcs are easily extinguished.
  • Alternate arrangements for directing liquid spray into the are 26 are possible to speed up vaporization and intensify the cooling and deionization of the arc 26.
  • the high pressure developed by the liquid SF closes the check valve 29 to prevent wasteful flow into the puffer cylinder 15 and possibly forcing back the puffer piston 14.
  • FIG. 5 diagrammatically illustrates a radial distribution system. It will be noted that fault current flows through all four breakers A, B, C, and D, but only breaker D should be tripped, so that onlyvthe faulted section of the system would be disconnected, leaving power flowing to all the other sections. Thus, there is no need for over-current responsive valves in breakers A, B, and C to be turned on, since these three breakers should not have to be tripped.
  • breaker A should trip only if the fault were on the bus section between breakers A and B.
  • the circuit interrupter uses two sources of gas blast to accomplish arc quenching.
  • One of these, for instance, a putter piston provides gas flow, preferably of sulfur-hexafluoride (SP gas, sufficient to extinguish arcs in a range up to moderate current values of several thousand amperes.
  • SP gas sulfur-hexafluoride
  • a second source consisting of a reservoir containing fluid under high pressure in either the gaseous or liquid state, is selectively controlled to come into action only when high currents above the range handled by the first source are to be interrupted.
  • My invention specifically avoids this undesirable situation by using a current-responsive element, which does not produce a gas blast directly, as by opening a valve, but rather sets up conditions under overload that will cause the high-pressure fluid blast to be activated if, and only if, the breaker is actually tripped.
  • the construction shown in FIG. 2 involves current-initiated magnetic means for aligning a cam-operating surface with the cam line of action, so that the opening movement of the breaker will operate the auxiliary blast valve on high-current overload conditions only. However, if the breaker is not tripped,
  • a normal, relatively lowcurrent extinguishing means 99 including a piston device 91, sends a normal relatively low-current fluid flow through a blast pipe 92.
  • This is analogous to the pufler device 14, 15 of FIG. 2, which is normally used for loadcarrying operation of the breaker.
  • the improved circuit-interrupting arrangements of the present invention condition the breaker in response to overload or fault conditions to cause the flow of fluid from the second auxiliary overload current source only when the breaker is actually tripped open.
  • the mere passage of overload current through the breaker does not in and of itself effect opening of the overload current blast valve 49, 49.
  • the arrangement is such as to merely condition the circuit interrupter so that only during an actual tripping operation is there brought into play the supplementary source of arc-extinguishing fluid.
  • a selective magnetically-actuated valve structure for a fluid-blast circuit interrupter including contact structure separable to establish an are, a split magnetic ring surrounding said contact structure, a movable armature,
  • a cam sleeve carrying a cam lug and pivotally connected to said movable armature, blast-valve releasing means, a blast valve lever carrying a cam lug, whereby currents above a predetermined magnitude passing through said contact structure will effect movement of the armature to bring the cam lug and the valve cam follower into alignment to effect releasing of said blast means.
  • a fluid-blast circuit interrupter including contact means for establishing an arc, a first normal fluid-extinguishing means for interrupting said are under normal load-carrying operation of the interrupter, a second auxiliary fluid-extinguishing means for interrupting said are only under predetermined fault-current interrupting conditions including a fluid control valve therefor, currentresponsive conditioning means responsive tothe current flow through said contact means and operable only at current values above a predetermined current magnitude for conditioning said control valve to render the latter capable of opening and thereby releasing a blast of fluid from said second auxiliary fluid-extinguishing means, operating means for mechanically opening said contact means, means for initiating operation of said operating means, and means responsive only to the activation of said last-mentioned means to effect actual opening of the conditioned control valve for obtaining fluid flow from said second auxiliary fluid-extinguishing means for fault-current interruption.
  • the currentresponsive conditioning means includes a split magnetic ring surrounding the contact means and a movable armature selectively responsive to currents above a predetermined current magnitude.

Landscapes

  • Circuit Breakers (AREA)
  • Driving Mechanisms And Operating Circuits Of Arc-Extinguishing High-Tension Switches (AREA)
US452451A 1961-07-20 1965-04-23 Fluid-blast circuit interrupters with two selectively-operated fluid-blast sources Expired - Lifetime US3257533A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US452451A US3257533A (en) 1965-04-23 1965-04-23 Fluid-blast circuit interrupters with two selectively-operated fluid-blast sources
DEW40928A DE1229621B (de) 1965-04-23 1966-02-09 Leistungsschalter
CH295766A CH464317A (de) 1961-07-20 1966-03-02 Leistungsschalter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US452451A US3257533A (en) 1965-04-23 1965-04-23 Fluid-blast circuit interrupters with two selectively-operated fluid-blast sources

Publications (1)

Publication Number Publication Date
US3257533A true US3257533A (en) 1966-06-21

Family

ID=23796502

Family Applications (1)

Application Number Title Priority Date Filing Date
US452451A Expired - Lifetime US3257533A (en) 1961-07-20 1965-04-23 Fluid-blast circuit interrupters with two selectively-operated fluid-blast sources

Country Status (2)

Country Link
US (1) US3257533A (de)
DE (1) DE1229621B (de)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3406269A (en) * 1965-02-26 1968-10-15 Westinghouse Electric Corp Fluid-blast circuit breakers having means for increasing the density of the fluid during interruption
US3418440A (en) * 1965-09-14 1968-12-24 Gen Electric Gas-blast circuit breaker
US3471667A (en) * 1967-07-21 1969-10-07 Gen Electric Double exhaust gas blast circuit breaker
US3538282A (en) * 1966-11-29 1970-11-03 Westinghouse Electric Corp Fluid-blast circuit interrupters with exhaust valves responsive solely to the pressure generated by an arc of excessive magnitude
US3720799A (en) * 1969-12-11 1973-03-13 Bbc Brown Boveri & Cie Gas blast circuit breaker
US4273978A (en) * 1978-06-09 1981-06-16 Electric Power Research Institute, Inc. Liquid interrupter module
WO2016005435A1 (fr) * 2014-07-08 2016-01-14 Alstom Technology Ltd Disjoncteur self-blast utilisant l'etat diphasique d'un gaz pour ameliorer les proprietes de coupure
WO2017178761A1 (fr) * 2016-04-13 2017-10-19 Supergrid Institute Disjoncteur électrique avec système de vaporisation liquide

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1334645A (en) * 1917-01-13 1920-03-23 Bechoff Ferdinand Air-break switch
US1852614A (en) * 1929-05-10 1932-04-05 Westinghouse Electric & Mfg Co Flashover relay
GB475370A (en) * 1936-06-12 1937-11-18 Gen Electric Co Ltd Improvements in or relating to alternating current electric switches
USRE21125E (en) * 1939-06-20 Switch
GB538554A (en) * 1938-11-08 1941-08-08 New Britain Machine Co Improvement in devices for applying power to brake members
US2484863A (en) * 1943-08-12 1949-10-18 Pierce John B Foundation Overload protective device
DE1107318B (de) * 1960-03-30 1961-05-25 Siemens Ag Elektrischer Schalter
US3033962A (en) * 1958-04-29 1962-05-08 Westinghouse Electric Corp Circuit interrupters
US3095490A (en) * 1960-02-26 1963-06-25 Westinghouse Electric Corp Circuit interrupters
US3150245A (en) * 1957-09-13 1964-09-22 Westinghouse Electric Corp Liquefied gas circuit interrupters

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE21125E (en) * 1939-06-20 Switch
US1334645A (en) * 1917-01-13 1920-03-23 Bechoff Ferdinand Air-break switch
US1852614A (en) * 1929-05-10 1932-04-05 Westinghouse Electric & Mfg Co Flashover relay
GB475370A (en) * 1936-06-12 1937-11-18 Gen Electric Co Ltd Improvements in or relating to alternating current electric switches
GB538554A (en) * 1938-11-08 1941-08-08 New Britain Machine Co Improvement in devices for applying power to brake members
US2484863A (en) * 1943-08-12 1949-10-18 Pierce John B Foundation Overload protective device
US3150245A (en) * 1957-09-13 1964-09-22 Westinghouse Electric Corp Liquefied gas circuit interrupters
US3033962A (en) * 1958-04-29 1962-05-08 Westinghouse Electric Corp Circuit interrupters
US3095490A (en) * 1960-02-26 1963-06-25 Westinghouse Electric Corp Circuit interrupters
DE1107318B (de) * 1960-03-30 1961-05-25 Siemens Ag Elektrischer Schalter

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3406269A (en) * 1965-02-26 1968-10-15 Westinghouse Electric Corp Fluid-blast circuit breakers having means for increasing the density of the fluid during interruption
US3418440A (en) * 1965-09-14 1968-12-24 Gen Electric Gas-blast circuit breaker
US3538282A (en) * 1966-11-29 1970-11-03 Westinghouse Electric Corp Fluid-blast circuit interrupters with exhaust valves responsive solely to the pressure generated by an arc of excessive magnitude
US3471667A (en) * 1967-07-21 1969-10-07 Gen Electric Double exhaust gas blast circuit breaker
US3720799A (en) * 1969-12-11 1973-03-13 Bbc Brown Boveri & Cie Gas blast circuit breaker
US4273978A (en) * 1978-06-09 1981-06-16 Electric Power Research Institute, Inc. Liquid interrupter module
WO2016005435A1 (fr) * 2014-07-08 2016-01-14 Alstom Technology Ltd Disjoncteur self-blast utilisant l'etat diphasique d'un gaz pour ameliorer les proprietes de coupure
FR3023649A1 (fr) * 2014-07-08 2016-01-15 Alstom Technology Ltd Disjoncteur utilisant l'etat diphasique d'un gaz pour ameliorer les proprietes de coupure
WO2017178761A1 (fr) * 2016-04-13 2017-10-19 Supergrid Institute Disjoncteur électrique avec système de vaporisation liquide
FR3050312A1 (fr) * 2016-04-13 2017-10-20 Inst Supergrid Disjoncteur electrique avec systeme de vaporisation liquide

Also Published As

Publication number Publication date
DE1229621B (de) 1966-12-01

Similar Documents

Publication Publication Date Title
US2748226A (en) Compressed-gas circuit interrupter
US2459600A (en) Compressed gas circuit interrupter
US2459599A (en) Circuit interrupter
US4309581A (en) Gas circuit breaker having independent main and arcing circuits
US3238340A (en) Gas-blast circuit breaker
US3009042A (en) Circuit interrupters
US3257533A (en) Fluid-blast circuit interrupters with two selectively-operated fluid-blast sources
US3114815A (en) Fluid-blast circuit interrupter with improved current-transformer housing means
US3045086A (en) Circuit interrupters
US3549842A (en) Fluid-blast circuit interrupter with piston assembly and electromagnetic driving means
US3290469A (en) Compressed-gas circuit interrupter having cavitation means
US4000387A (en) Puffer-type gas circuit-interrupter
US3275778A (en) Compressed-gas circuit interrupter with pressurized arcing chamber and downstream blast valve
US3551625A (en) Circuit breakers
US3551623A (en) Fluid-blast circuit interrupters with piston-driving means and cooperable floating piston with accelerating coil
US3943314A (en) Motion-multiplying linkage-mechanism for sealed-casing structures
US3356809A (en) Multi-break compressed-gas circuit interrupters with rotating gasconducting bridging members
US3379849A (en) Dual-pressure gas-blast circuit breaker with piston means and interrupting unit in closed tank
US3813507A (en) Synchronous puffer circuit breaker
US2581571A (en) Circuit interrupter
US2924690A (en) Circuit interrupters
US3311726A (en) Puffer-type fluid-blast circuit interrupter with pressurized casing for actuating driving piston
US3390240A (en) Circuit breaker with piston gas flow and selective synchronous operation
US3246108A (en) Arc-extinguishing structure and tank housing for a compressed-gas circuit interrupter
US3538282A (en) Fluid-blast circuit interrupters with exhaust valves responsive solely to the pressure generated by an arc of excessive magnitude