CA1036644A - Circuit-interrupter - Google Patents
Circuit-interrupterInfo
- Publication number
- CA1036644A CA1036644A CA229,201A CA229201A CA1036644A CA 1036644 A CA1036644 A CA 1036644A CA 229201 A CA229201 A CA 229201A CA 1036644 A CA1036644 A CA 1036644A
- Authority
- CA
- Canada
- Prior art keywords
- contact
- reverse
- operating
- current
- movable
- 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
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H1/00—Contacts
- H01H1/50—Means for increasing contact pressure, preventing vibration of contacts, holding contacts together after engagement, or biasing contacts to the open position
- H01H1/54—Means for increasing contact pressure, preventing vibration of contacts, holding contacts together after engagement, or biasing contacts to the open position by magnetic force
-
- 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
- H01H33/28—Power arrangements internal to the switch for operating the driving mechanism
- H01H33/38—Power arrangements internal to the switch for operating the driving mechanism using electromagnet
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H77/00—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting
- H01H77/02—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting in which the excess current itself provides the energy for opening the contacts, and having a separate reset mechanism
- H01H77/10—Protective overload circuit-breaking switches operated by excess current and requiring separate action for resetting in which the excess current itself provides the energy for opening the contacts, and having a separate reset mechanism with electrodynamic opening
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Driving Mechanisms And Operating Circuits Of Arc-Extinguishing High-Tension Switches (AREA)
- High-Tension Arc-Extinguishing Switches Without Spraying Means (AREA)
- Resistance Welding (AREA)
- Manufacture Of Switches (AREA)
- Electromagnets (AREA)
Abstract
ABSTRACT OF THE INVENTION
In the improved operating mechanism of the instant invention there is associated with the rotatable contact-operating arm an abutment member, such as a plate, for example, which is associated with the contact-pressure spring, and a reverse-current loop arm pivotally mounted to the contact-actuating arm has a nose portion bearing on said abutment member or plate, and operable during the de-energized condition of the magnet to act in an opening direction against said abutment plate, and have its fulcrum point at the pivot-shaft location between the contact-actuating arm and the movable contact stem. Thus, magnetic forces are brought into play to redirect the reverse-current loop effect, and to pry, in effect, the welded contacts apart, and thereby assist the opening accelerating springs of the circuit-interrupter or contactor.
In the improved operating mechanism of the instant invention there is associated with the rotatable contact-operating arm an abutment member, such as a plate, for example, which is associated with the contact-pressure spring, and a reverse-current loop arm pivotally mounted to the contact-actuating arm has a nose portion bearing on said abutment member or plate, and operable during the de-energized condition of the magnet to act in an opening direction against said abutment plate, and have its fulcrum point at the pivot-shaft location between the contact-actuating arm and the movable contact stem. Thus, magnetic forces are brought into play to redirect the reverse-current loop effect, and to pry, in effect, the welded contacts apart, and thereby assist the opening accelerating springs of the circuit-interrupter or contactor.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
A related Canadian patent application by A. W. Hodgson, Serial No. 228,892, filed 7une 9, 1975 entitled "Improved Movable Contact-Stem Operator For A Vacuum-Type Circuit-Interrupter", and assigned to the assignee of the instant : patent applicatlon, discloses ~nd claims the means for adjustment of the movable contact-stem operator for the movable contact of the circuit-interrupter disclosed herein.
;. BACKGROUND OF THE INVENTION
Circuit-interrupters particularly of the vacuum-type are relatively new on the commer~ial market, and have enjoyed only limited success due to several severe ~hort-` comings. In an effort to minimize the most serious of these shortcomings, the vacuum-interrupter manufactures have found . --1-- ~
. '.
. : .. .. , : .
~(~36644 it necessary to use contact materials which are susceptible to welding. me welding problem, however, can be minimized by the use of contact and weld-breaking ~orces approximately ten times those usually iound in a conventional air-break contactor o~ comparable rating.
Vacuum-interrupters having the most desirable ~ interrupting characteristics and longest contact life have --- been found to weld at currents considerably below their interrupting limit, so that the interrupter rating o~ a con-tactor using these vacuum-type circuit-interrupters is limited by the ability of the actuating or operating mechanism to overcome the welding problem, rather than by .- :
the arc-interrupting ability o~ the vacuum-type circuit-interrupter.
;'' '''' '~ ~ :'' ' ,~ ' ~'.
A related Canadian patent application by A. W. Hodgson, Serial No. 228,892, filed 7une 9, 1975 entitled "Improved Movable Contact-Stem Operator For A Vacuum-Type Circuit-Interrupter", and assigned to the assignee of the instant : patent applicatlon, discloses ~nd claims the means for adjustment of the movable contact-stem operator for the movable contact of the circuit-interrupter disclosed herein.
;. BACKGROUND OF THE INVENTION
Circuit-interrupters particularly of the vacuum-type are relatively new on the commer~ial market, and have enjoyed only limited success due to several severe ~hort-` comings. In an effort to minimize the most serious of these shortcomings, the vacuum-interrupter manufactures have found . --1-- ~
. '.
. : .. .. , : .
~(~36644 it necessary to use contact materials which are susceptible to welding. me welding problem, however, can be minimized by the use of contact and weld-breaking ~orces approximately ten times those usually iound in a conventional air-break contactor o~ comparable rating.
Vacuum-interrupters having the most desirable ~ interrupting characteristics and longest contact life have --- been found to weld at currents considerably below their interrupting limit, so that the interrupter rating o~ a con-tactor using these vacuum-type circuit-interrupters is limited by the ability of the actuating or operating mechanism to overcome the welding problem, rather than by .- :
the arc-interrupting ability o~ the vacuum-type circuit-interrupter.
;'' '''' '~ ~ :'' ' ,~ ' ~'.
-2-~ - , :, .
43,102 .. . .
10366~
A three-pole contactor having a magnet and frame as embly proportloned to meet the design requlrements of the vacuum-lnterrupter, and stlll have a reasonable mechanical llfe would be much too large and costly to compete with exlstlng alr break contactors whlch require only a fraction of the contact force. As result of thls "squeeze", presently-avallable vacuum-type contactors, are a design compromlse whlch do not completely satlsfy the requirements of the vacuum-lnterrupter, and as a result do not perform as well as exlst-..;
~` 10 ing available alr-break contactors.
The very hlgh contact forces mentioned above are requlred only when lt ls necessary to obtaln the maximum .:
monentary current rating of the vacuum-lnterrupter, whlch is ln the event of a power-system fault. Slnce the contactor may ~eldom see thls current conditlon ln actual service, a ,i,j ., ~ , ~
s, contactor deslgned to contlnuously provlde these high contact- ~
.
; closlng forces would represent a rather lnefflclent use of space and materlal.
A reasonable-slzed operatlng magnet, coupled to the lnterrupter shaft through a toggle mechanlsm, or other system of levers, could be devlsed to develop hlgh contact closing forces, but the hlgh mechanlcal advantage of thls mechanlsm would act to reduce the contact-operatlng speed far below the - values recommended for the vacuum lnterrupter. The high mechanlcal advantage of thls mechanlsm would, in addltlon, result ln low or dlminished contact overtravel, whlch, ln turn, would make frequent ad~ustment of contact overtravel necessary.
-~ Reverse-current loops have been employed ln the past to increase the contact-closing forces under heavy ~ 43,102 . '. ' .: ,'
43,102 .. . .
10366~
A three-pole contactor having a magnet and frame as embly proportloned to meet the design requlrements of the vacuum-lnterrupter, and stlll have a reasonable mechanical llfe would be much too large and costly to compete with exlstlng alr break contactors whlch require only a fraction of the contact force. As result of thls "squeeze", presently-avallable vacuum-type contactors, are a design compromlse whlch do not completely satlsfy the requirements of the vacuum-lnterrupter, and as a result do not perform as well as exlst-..;
~` 10 ing available alr-break contactors.
The very hlgh contact forces mentioned above are requlred only when lt ls necessary to obtaln the maximum .:
monentary current rating of the vacuum-lnterrupter, whlch is ln the event of a power-system fault. Slnce the contactor may ~eldom see thls current conditlon ln actual service, a ,i,j ., ~ , ~
s, contactor deslgned to contlnuously provlde these high contact- ~
.
; closlng forces would represent a rather lnefflclent use of space and materlal.
A reasonable-slzed operatlng magnet, coupled to the lnterrupter shaft through a toggle mechanlsm, or other system of levers, could be devlsed to develop hlgh contact closing forces, but the hlgh mechanlcal advantage of thls mechanlsm would act to reduce the contact-operatlng speed far below the - values recommended for the vacuum lnterrupter. The high mechanlcal advantage of thls mechanlsm would, in addltlon, result ln low or dlminished contact overtravel, whlch, ln turn, would make frequent ad~ustment of contact overtravel necessary.
-~ Reverse-current loops have been employed ln the past to increase the contact-closing forces under heavy ~ 43,102 . '. ' .: ,'
3~i69~4 fault condltions, but have had the tendency to override the operatlng magnet. A reverse-current loop of this type, ; deslgned to supply the requlred contact-closlng forces of a three-pole vacuum contactor, would exert so much force that the reverse-current loop would hold the contacts and magnet - closed even after the magnet ls de-energlzed. A weak reverse-current loop of this type would not hold the contacts closed, but would act to reduce opening speed and weld-breaking forces, which ls also undeslrable.
SUMMARY OF THE INVENTION
;~ In the improved vacuum-type clrcuit-interrupter and mechanlsm of bhe present lnventlon, the contact closlng ~ sprlngs, operatlng magnet and other structure are pro-- portloned to provide the proper contact closing forces sufflclent to lnsure satlsfactory performance under motor startlng, runnlng, and locked-rotor condltions for the maxlmum sized motor with which the contactor wlll be used.
; The operatlng mechanlsm for the separable contacts of the vacuum-type clrcult-lnterrupter ls such that a reverse-current loop ls employed ln con~unction therewlth whlch has two opposltely-directed functions. In the closed-circuit position of the circult-lnterrupter, or contactor, with the magnet energlzed, the fulcrum point of the reverse-current actuating arm is so located that upon a sudden lncrease of the current magnltude passlng through the circult-interrupter, ., or stated otherwise, under heavy-fault conditlons exlstlng ln ;~
the controlled clrcuit, the magnetlc forces ln ~he reverse-. . .
current loop structure are directed to lncrease the contact-: clo~ing forces, thereby asslstlng the contact-sprlng pressure provlded by the operating mechanlsm ltself.
SUMMARY OF THE INVENTION
;~ In the improved vacuum-type clrcuit-interrupter and mechanlsm of bhe present lnventlon, the contact closlng ~ sprlngs, operatlng magnet and other structure are pro-- portloned to provide the proper contact closing forces sufflclent to lnsure satlsfactory performance under motor startlng, runnlng, and locked-rotor condltions for the maxlmum sized motor with which the contactor wlll be used.
; The operatlng mechanlsm for the separable contacts of the vacuum-type clrcult-lnterrupter ls such that a reverse-current loop ls employed ln con~unction therewlth whlch has two opposltely-directed functions. In the closed-circuit position of the circult-lnterrupter, or contactor, with the magnet energlzed, the fulcrum point of the reverse-current actuating arm is so located that upon a sudden lncrease of the current magnltude passlng through the circult-interrupter, ., or stated otherwise, under heavy-fault conditlons exlstlng ln ;~
the controlled clrcuit, the magnetlc forces ln ~he reverse-. . .
current loop structure are directed to lncrease the contact-: clo~ing forces, thereby asslstlng the contact-sprlng pressure provlded by the operating mechanlsm ltself.
4-i '.
, - .. . . .. , ,. , , . . :
` 43,102 ~` ~
i, . .
However, when it ls desired, on the other hand, to open the contacts of the vacuum-type clrcuit-lnterrupter, or contactor, the de-energization of the operatlng magnet wlll be reflected through the disclosed linkage structure to change the location of the fulcrum point of the reverse-current act~atlng arm to thereby bring about an opposlte function or effect of the reverse-current loop structure, or ln other words, ~o redirect the forces created by the verse-current loop structure, so that at this tlme the magnetic forces, generated by the reverse-current loop structure, actually asslst the operatlng mechanism to open the separable contacts, and to break any welded condition exlstlng at the contacts themselves.
Thus, the lmproved reverse-current loop structure . i .
of the present lnvention has two lmportant functions. The ;; flrst function is to lncrease the contact-closlng forces, , thereby asslsting the contact-pressure sprlngs ln the closed-clrcult position of the circuit-interrupter, when the magnet structure is energized, under the conditlons Or high-fault current passing through the interrupter. In thls case, con-¢eivably a remote clrcuit-breaker would be desired to open the circuit rather than the contactor and the magnet would remain energlzed as desiredO Depending on whether the oper-ating magnet of the contactor is energized or not, depends - upon whether or not the fulcrum point of the reverse-current actuating arm changes, and thereby affects the function and operation of the reverse-current loop system.
Assuming, for instance, that lt ls desired to open the circuit-interrupter, or contactor, the de-enèrgization Or 30 the operating magnet structure wlll effect automatically a -~
, - .. . . .. , ,. , , . . :
` 43,102 ~` ~
i, . .
However, when it ls desired, on the other hand, to open the contacts of the vacuum-type clrcuit-lnterrupter, or contactor, the de-energization of the operatlng magnet wlll be reflected through the disclosed linkage structure to change the location of the fulcrum point of the reverse-current act~atlng arm to thereby bring about an opposlte function or effect of the reverse-current loop structure, or ln other words, ~o redirect the forces created by the verse-current loop structure, so that at this tlme the magnetic forces, generated by the reverse-current loop structure, actually asslst the operatlng mechanism to open the separable contacts, and to break any welded condition exlstlng at the contacts themselves.
Thus, the lmproved reverse-current loop structure . i .
of the present lnvention has two lmportant functions. The ;; flrst function is to lncrease the contact-closlng forces, , thereby asslsting the contact-pressure sprlngs ln the closed-clrcult position of the circuit-interrupter, when the magnet structure is energized, under the conditlons Or high-fault current passing through the interrupter. In thls case, con-¢eivably a remote clrcuit-breaker would be desired to open the circuit rather than the contactor and the magnet would remain energlzed as desiredO Depending on whether the oper-ating magnet of the contactor is energized or not, depends - upon whether or not the fulcrum point of the reverse-current actuating arm changes, and thereby affects the function and operation of the reverse-current loop system.
Assuming, for instance, that lt ls desired to open the circuit-interrupter, or contactor, the de-enèrgization Or 30 the operating magnet structure wlll effect automatically a -~
-5-.;. ~ , :
43,102 -~3~ ~;
relocation of the fulcrum point of the reverse-current actuatlng arm and thereby drastically change the operatlng function of the reverse-current loop system to thereby result in an entirely oppositely-dlrected force, this time a force directed to open the separable contacts and thus to break any ;-welding condltlons existing thereat. `
In the lmproved operatlng mechanism of the instant ~-invention there ls associated with the rotatable contact-operating arm an abutment member, such as a plate, for example, which ls associated with the contact-pressure spring, and a reverse-current loop arm pivotally mounted to the contact-actuating arm has a nose portion bearing on said abutment member or plate, and operable during the de-energized conditlon of the magnet to act in an opening directlor. against sald abutment plate, and have lts fulcrum point at the pivot-shaft location between the contact-actuating arm and the movable contact stem. Thus, magnetic forces are brought lnto play to redirect the reverse-current loop effect, and to pry, in effect, .. .
the welded contacts apart, and thereby asslst the opening accelerating springs of the circuit-interrupter or contactor.
In more detall, the reverse-current loop system of the present lnvention comprises a metallic conductlng arm carrying the line current to the interrupter contacts, and , . ..
` pivotally mounted on the same plvot shaft location at which the rotatable contact operating arm pivotally connects to the movable contact stem of the vacuum-interrupter. By thus ~ belng pivoted to the movable contact stem with the rotatable ; contact-actuating arm during heavey-fault current condition, the magnet repelling effect between the sldes of the loop ~-forces the separable contacts more firmly closed under high-' -6-` 43,102 , 1~3664~
fault condltions, when the magnet ls energlzed, as ls desired.
On the other hand, durlng the opening operation, when the operating magnet ls de-energized, and thy operating mechanism is stalled at the contact-touch point, due to a welded condition exlsting at the separable contacts; or in other words, the contacts are, in fact, welded closed, the reverse-current loop arm acts ln a manner to break the con-tact weld by relocating the fulcrum point, of the reverse-current actuatlng arm so thRt it now exists at the pivot : 10 polnt for the rotatable contact aPm with the movable contact stem.
Another very important feature of the present invention is the structure for supplying or feeding series current to the reverse-current loop arm, so that it does not oppose or tend to neutralize the magnetic action of the reverse-current loop arm. This is achieved by a speclal ~. stationary current-feed clrcuit, which locates the current-feeding arms in roughly the same plane as the movable portion o~ the reverse-current loop arm, so that, the fact, the `~ 20 magnetic effect, generated at the two sationary current-feed arms, is to increase and augment the magnetic effect . .
exerted on the movable portion of the reverse-current loop-. ~ , ,.
- arm structure.
BRIEF DESCRIPTION OF THE DRAWINGS ~ ~ :
Fig. 1 is a perspective vlew of motor-starter equip-~ ment including two motor starters disposed in superimposed ~ relation together with their disconnectlng-swltch structures;
, .
Fig. 2 is an enlarged vlew looklng lnto the interior of a cell-structure adaptable for accommodatlng the improved ~ ;
30 roll-in vacuum-type circuit-interrupter structure of the : , .:
-7- :
43,102 .
lQ36644 ~
instant inventlon, wlth the access doors for the low and hlgh-voltage compartments being open;
Flg. 3 is a side-elevational vlew of the right slde of the truck-mounted contactor, or interrupter assembly of the - lnstant invention;
Fig. 4 i3 a s~de-elevational vlew of the lefthand slde of the truck-mounted vacuum-interrupter assembly of the present invention;
Fig. 5 is a front elevational v~ew looklng at the ;~
, lO front of the truck-mounted vacuum-type circuit-lnterrupter ; assembly of the present lnventlon;
Fig. 6 is a vertical sectional vlew taken sub-stantially along the line VI-VI of Fig. 5 with the separable-contact structure closed;
Fig. 7 ls an enlarged detalled vlew of the oper-atlng llnkage and mechanism structure of Fig. 6, again the ~ ~-separable contacts of the vacuum-type circuit-interrupter assembly belng lllustrated in the closed-circult positlon with the operatlng magnet energized;
Fig. 8 ls a fragmentary vertlcal sectlon view taken substantlally along line VIII-VIII of Fig. 7, again the con-tact structure belng shown in the closed-clrcult positlon;
Flg. 9 ls a vlew slmllar to that of Fig. 7, but lllustrating the separable contacts of the vacuum-lnterrupter `~ unlt ln the fully-open ciruit position with the operatlng magnet de-energlzed;
Flg. lO is an exploded perspectlve vlew of the several parts employed ln con~unction with the lm~rovèd operating mechanism of the ln~tant lnventlon, Fig. ll i a ~omewhat diagrammatlc view of the com-43,102 lQ36644 ponent parts of a motor-starter equlpment for controlllng motor installations with the disconnecting switch shown closed, and also the contactor assembly being shown in the closed-circuit position, the truck-mounted elements being illustrated ln their in-cell operating condition;
Fig. 12 is a top plan view of the reverse-current ~eeder circuit illustrating the structure thereof;
Fig. 13 ls a side-elevational view of the reverse-!''' current ~eeder structure of Flg. 12;
Flg, 14 i8 a front elevational view of a component .
part of the improved reverse-current feeder circuit of Figs.
12 and 13;
Fig. 15 is a diagrammatic v~ew illustrating a single-actlng reverse-current loop structure with the contacts tnot - shown) closed, and electrical current passlng through the reverse-current loop structure;
;....... :,:
Fig. 16 illustrates diagrammatically a double- i;
acting reverse-current loop structure utillzing some of the principles of the present lnvention, but lllustratlng a con-dition Or a feeder connection structure, whlch is not com-.... ; . .
~ mercially approprlate or desirable, the contact structure ~ ...... . .
- (not shown) being lllustrated in the closed-circuit position, and again electrical current belng lllustrated as passing ~ ;
through the double-acting reverse-current loop; ~ ~;
Fig. 17 illustrates diagrammatically the improved relocation of the feeder circuit structure of Fig. 16, in which the double-acting reverse-current loop is adversely `
magnetically a~fected by the particular feeder circuit arrange-ment illustrated in Fig. 17, which is, of course, undesirable;
Fig. 18 illustrates diagrammatically the closed-.... .. . . . .. . .. .
43,102 ~Q3~;6~
circuit;posltion of the vacuum-type circuit-lnterrupter of the present invention, illustrating the passage of current -through the reverse-current loop, illustratlng the location of the pivot point or fulcrum point for the reverse-current loop arm, with the operating magnet energized, and durlng the exlstence of hlgh-fault current conditions existing in the !l separable contacts of the vacuum-type circuit-interrupter, the latter being lllustrated as in the cldsed-circuit position;
Fig. 19 is a sectional vlew taken substantially 10 along the line XIX-XIX of Fig. 18; -Fig. 20 illustrates a de-energized condition of the vacuum-type circuit-interrupter of Figs. 18 and 19, showing a relocation of the pivot point or fulcrum point for the reverse current loop arm structure, and the magnetic repulsive forces encountered, the view also illustrating the improved ~eeder-current connections to the reverse-current loop-arm;
. .
Fig. 21 illustrates a fragmentary sectional view taken along the line XXI-XXI of Fig. 20, lllustrating the current-flow conditions, and only showing the feeder-current connector system;
Fig. 22 is a sectional vlew taken substantially along the line XXII-XXII of Fig. 20 illustrating diagram-matically the magnetic lines of force associated with the improved feeder-current system of the present invention;
Fig. 23 illustrates a sectlonal view taken through the improved shoulder-bolt and movable-contact operator con-nection for actuating the movable-contact stem of the vacuum-type circuit-interrupter of the present lnvention;
Fig. 24 is an enlarged side-elevational vlew of the improved movable-contact operator utilized, -10- ;` ' '' '.' : ' , . . :. .. ~ - : . .
1~)36644 Fig. 25 is a side-elevational view of the improved - movable-contact operator of Fig. 24;
Fig. 26 is a top-plan view of the improved movable-contact operator of Fig. 2~;
Fig. 27 is an inverse plan view of the improved movable-contact operator of Fig. 24;
Fig. 2~ illustrates in side elevation the accurately-machined lower interrupter support-plate utilized in the present invention;
Fig. 29 is an inverted plan view of the accurately-machined interrupter support structure of Fig. 2g;
Fig. 30 is a side-elevational view o~ the improved accurately-machined interrupter support of Figs. 2~ and 29; ~
Figs. 31-33 are enlarged detail views of the top ;;
~ . . .
interrupter clamp for connecting to the stationary contact stem of the vacuum interrupter;
Fig. 3~ illustrates diagrammatically the wiring -.
diagram for the starter assembly of the present invention; and 'r; Figs. 35-37 illustrate an application of the mechan-.` 20ism to a modified-type of arc-interrupting structure.
` DESCRIPTION OF THE PREFERRED EMBOD ENT
.
The present invention has particular applicability ,` to high-voltage motor starters 1 designed for starting and con-... .. :~
trolling alternating-current motors. Generally, these ~ ~
..,.. ~, .
starters 1 are supplied in a steel floor-mounted enclosure 2, such as set forth in Fig. 1. The steel floor-mounted enclosure 2 may, for example, accommodate two motor starters 1, as actually shown in Fig. 1 disposed in superimposed relation.
As set forth in Fig. 11, each high-voltage motor-~.
starter apparatus 1 comprises a cabinet housing 2 in which high-voltage modular plug-in assemblies corresponding to an .' . ' -.~ . .
-~~ 43,102 ;, , lQ3~69~4 isolating-switch assembly 3, a power-fuse assembly 5 and a contactor assembly 7 are secured. The cabinet houslng 2 ls ,, illustrated in Flg. 2 as compr~sing panels 9-11 and supporting ; ,-structure 13 assembled to form a front-entry single-compartment ~
. .
cabinet with access provlded by hinged access doors 15 and ', 17. Mounted on the lnterlor surface of the back panel 10 .
are electrlcal terminal assemblles 19 and 21 whlch electrlcally engage an lsolating-switch assembly 3 and the contactor assembly 7, reQpectlvelyO The three-phase output power de-veloped by the hlgh-voltage apparatus 23 ls conducted through cables 25, which pass through current transformers 27 to a load terminal assembly 29 for connection to a remote electrical clrcuit (not shown). This clrcuit could, of course, be motor controlled equlpment. Secured,,to the interior surface of the right-hand panel of the cabinet houslng 2 ls the low-voltage clrcuitry 31, which is electrlcal-ly connected through sultable ~ransrormer means 33, to pro-vide safe access ~or monitoring the operation of the hlgh-voltage plug-ln assemblies.
~' 20 The hlgh-voltage motor-starter apparatus 23 of Flg.
11, for example, may require a slngle contactor assembly 7, and therefore supports the compact modular packaging scheme illustrated, ln which the modular assemblies 3, 5 and 7 can ,, be quickly removed from the houslng cablnet 2 merely by slid-lng the assemblles 3, 5 and 7 forward through the cabYnet opening provided by the access door 15.
The high-voltage motor-starter apparatus, sche- ' ~ '' matically illustrated in Fig. 11, is set forth, in detail, in - !' the follo~lng patents: U.SO Patent 3,602~680, issued August ~. . .
31, 1971 to Alfred W. Hodgson; U.S. Patent 3,639,873, issued ~-:.~ ,, ~ ' '.
- - ` 43,102 1~3~644 February 1, 1972 to Alfred W5 Hodgson; UOSo Patent 3,621,339, lssued November 16, 1971, to Alfred W. Hodgson; U.S. Patent 3,264, 431, issued August 2, 1966 to A. W. Hodgson; U.S.
Patent 3,264,432, lssued August 2, 1966 to A. W. Hodgson et al; , U.S. Patent 3,264,433 issued August 2, 1966 to R. D. Clark, Jr. et al; and U.S. Patent 3,290,468 lssued December 6, 1966 to R. D. Clark Jr. et al.
Sidewalls of the modular assemblies 3,5 and 7 cooperate ln an overlapping relatlonshlp in the cabinet housing 2 to define two cablnet compartments "A" and "B".
; Compartment "A" is deslgnated the hlgh-voltage component compartment wlth access provlded by door 15, and compartment "B" is designated the low-voltage circuitry compartment with ` access provided by door 170 As seen more clearly in Fig. 11, the isolation-switch assembly 3 comprlses a rotatable handle mechanlsm 35, which controls the positioning Or electrical contacts 37 to ; engage and to disengage electrical contact with the main power `~
lines which terminate at the electrloal tremlnal assembly 19.
20 The location o~ the isolation swltch assembly 3 ln the cablnet housing 2 ls selected to position the handle mechanism 35 at a convenlent operator height. ' ' The handle mechanism 35 ls described ln more detail ; `
in U.S. Patent No. 3,264,431 lssued August 2, 1966, and ; '~
assigned to the assignee of the present lnvention.
Access to the high-voltage compartment "A" is pre-vented''by an interlock system (not shown) when the handle mechanlsm 35 is in either the "OFF" or "ON" posltion. Access to compartment "A" is permitted when the handle mechanism 35 30 is rotated to a horlzontal positlon (not shown). A spring-i 43,102 ,:
, 1(~36644 loaded pin (not shown) must be manually depressed before the handle mechanism 35 can be rotated, thus preventing inadvertent isolatlon of the handle mechanism. Access to the low-voltage compartment "B" is provided by the door 17 regardless of the position Or the handle mechanism 35.
The contactor assembly 7 comprises electrically isolated contactor poles 39, 41 and 43 which represents - commercially-available components, such as the Westinghouse Electric Corporation contactor Type LF-50V430 contactor.
Contactor electrical terminal 45, as illustrated in Flg. 6, engages electrical terminal assembly 21 to supply voltage through the cables 25 to the remote load, which may be a motor lnstallatlon.
The lsolation switch assembly 3 ls slidably i' positioned within the cabinet housing 2 by outwardly-protrud-ing flanges which engage horlzontal guide tracks 47 (Fig. 2).
Due to the weight of the contactor assembly 7 lt is generally lcoated in the bottom section of the cablnet houslng , 2. The positioning of the contactor assembly 7 withln the cablnet hou~lng 2 18 accomplished by insertlng the wheels 49, : whlch are affixed at the four corners of the base 51 of the , ~ :
assembly 7, lnto the guide tracks 53 (Flg. 2) and rolllng the ; assembly 7 into the cabinet housing 2 until electrical engage-,~; ment with electrical terminal assembly 21 occurs. ~`
~- The vacuum-type contactor 7 is designed for starting ~ ~ , and controlling three phase, 50-60 cycle alternating-current ; motors. The voltage may, for example, be 6,600 and the con- ~ `
tactor-closed continuous rating in amperes 360.
Fig. 3 illustrates ln side elevatlon the rlght-; 30 hand side 55 of the truck-mounted vacuum-type contactor ' .: ' :, ' ~; ' 43,102 ~Q366~
assembly 7~ As illustrated in Figo 3, it will be observed that there is provlded a direct-current operating magnet 57 havlng a direct-current magnet coil, or operating coil 59.
Assoclated with the magnet structure 57 is a rotatable magnet armature 61 which makes abutting engagement when the operating magnet 57 is energized with the magnetic pole-face 63. The -lower end 61a of the rotatable magnet armature 61 is affixed by a clamp casting 65 and a key 67 to the external end of an operating shaft 69, as shown. Also afflxed to the operating ;
shaft 69 is an electrical interlock pushrod 71 which operates an electrical interlock 73, the purpose for which wlll be more apparent hereinafter. In addition, Fig. 3 shows a protective resistor 74 which iæ inserteid into the series magnet coil ~; -circuit 57 (Fig. 34) when the armature 61 has reached its ,~
fully-closed position against the pole face 63, as illustrated . :
by the full lines in Fig. 3O Additionally, there is illus-trated in Fig. 3 another interlock 77, the purpose for which will appear more fully herelnafter. Also Fig. 3 lllustrates an isolating-switch m~chanical interlock arm 78, which i9 ..
operable by a downwardly-extendlng interlock rod (not shown) extending downwardly and operable by the isolating-switch assembly 3 (Fig . 11).
, Flg. 3 shows that, general, the truck-mounted contactor assembly 7 comprises two side metallic support plates 80 and 81 interconnected by a front U-shaped metallic support channel member 83, which is more clearly illustrated in Fig. 5 of the drawings. Also Fig. 3 shows the lower stab ~;~ assembly 45 which interconnects the contactor assembly 7 with statlonary load termlnals 21 (Fig. 2) ~or operating an external piece of equipment, such as an electr~cal motor, for . .
- : . - , 43,102 1~3669~4 example.
Flg. 4 illustrates the other, or left-hand side 85 of the vacuum-type contactor assembly 7, which includeæ the other side metallic support plate 80, the two wheels 49 an interlock bar 87 associated with the levering-in mechanism, (not shown) whlch constitutes no part of the present invention.
A1BO Fig. 4 lllustrates the control transformer 33 whlch re-duces the voltage from the llne termlnals Ll, L2 and L3 to a suitable lower voltage level for operatlng the magnet coil 59 of the operating-magnet structure 57. Addltlonally, Fig. 4 shows the interphase barriers 89-92 a flange æupport plate 95 for supportlng the transformer 33 and also a fuse block 97 for the control circuitry 31. ~ -- Fig. 5 illustrates a view looking into the front of the truck-mounted vacuum-type clrcuit-lnterrupter assembly, or contactor assembly 7. It will be observed that the armature 61 of the operating magnet 57 ls affixed to the external end of the operatlng shaft 69 and effects the rotatable operating motlon thereof. The operatlng shaft 69 ; 20 i8, of course, ~ournaled ln sultable bearlngs 99, 101 pro-vided on the lnner side~ 80a, 81a of the two metallic side support plates 80 and 81. Fig. 5 more clearly qhows the fuse block 97, prevlously mentioned ln connectlon wlth Fig. 4, and also the control transformer 33 for the control clrcuitry 31.
It ls, of course, deslrable to provide contact-closlng sprlng pressure for each of the individual pole-unlts 39, 41 and 43 in the closed-circuit positlon of the contactor assembly 7, as illu3trated in Fig. 6 of the drawlngs. Each pole-unit 39, 41 or 43 is provlded with its own lndlvldual ..
vacuum-interrupter unit 103 and a pivotally-mounted rotatable :, ':
. -. ~
~3,102 lQ366~ .
contact operating arm 105, which is pivoted upon a statlonary pivot pin 107 extending between the two downwardly-extendlng flange portions 108, 109 of a U-shaped lower lnterrupter support 110, the conflguration of which is more readily apparent from a study of Figs. 28-30 of the drawings.
The rotatlon of the rotatable contact arm 105 is effected by a laterally-extending cross-bar 112 which is . . . : -moved in generally a vertical direction by two spaced crank-arms 114, 116 the latter being afflxed to and rotatable with , . . .. .
the operating shaft 69. Fig. 5, taken in conJunction with Fig. 6, more clearly shows the structure of the laterally-extending cross-bar 112. A~ illustrated in Fig. 6, it will -- be observed that the cross-bar 112 is preferably of metal, and in thls particular instance has a square cross-section, as shown, havlng end plvot-pins 118, the latter being apparent from a study of Flg. 5 of the drawlngs.
The cross -bar 112 is fixedly secured to an insu- -~
lator support 120 individual to each of the three pole-units 39, 41, and 43 as more clearly illustrated in Flg. 5. The lnsulator support 120, ln turn, supports an abutment member or ln this particlar in~tance a plate 122, for example, having a configuration more clearly apparent from a study of Fig. 10 of the drawings. Fig. 10 illustrates an exploded view of the contact-pressure spring assembly 124 and the relation~hip between the abutment member or plate 122 and a rotatable reverse-current loop-arm assembly 126, again the configuratlon of which ls more clearly apparent from a study of Flg. 10 of the drawings.
As well known by those skllled in the art, it 1 desirable to supply contact spring ~pr eSsSs~urrc on the se bl "-"; ,:
43,102 '' 1~36~4 ~
contacts in the closed-circuit posltion of the interrupter 103. This sprlng pressure, which is provided ln the lnstant lnventlon, ls afforded by a compresslon spring 128 -illustrated in Flgs. 6 and 10, and lnterposed between the abutment plate 122 and an upper movable sprlng seat 130, which straddles the two contact-actuating arms 105a, 105b, r which collectlvely constltute the movable contact-actuating arm 105 of the interrupter assembly 7. -It wlll be observed, in connection wlth Flgs. 6, 7 and 9 of the drawlngs, that a contact drlve pin 132 passes through the two leg portlons 105a, 105b Or the movable contact-actuatlng arm 105 and, addltlonally, passes through - a palr Or apertures 134 provided in the rotatable reverse-current actuatlng arm 136. In other words, the same pivot pln 132 passes through the two leg portlons 105a, 105b of the contact-actuatlng arm 105 and also through the leg portions 136a, 136b constitutlng the reverse-current arm-assembly 136, thereby enabllng a fulcrum polnt to be exerted at the plvot pln 132 in the contact-welded condltlon of the 20 separable contacts 138, 139 under certaln condltlons, as more fully descrlbed herelnafter.
Wlth reference to Flgs. 7, 9 and 10 of the drawlngs, lt wlll be observed that there ls provlded an overtravel - r ad~ustlng nut 140, whlch ls threaded upon the upper end 142a of a contact-pressure stud 142, the lower end of whlch ls secured into the upper end of the lnsulator support 120.
Thus, in the closed-circuit position of the vacuum-interrupter assembly 7, as illustrated in Fig. 7, the contact compression spring 128 is compressed, thereby apply~ng contact-closing 30 pressure between the separable contacts 138 and 139, the :' .
\ 43,102 1~36644 overtravel ad~usting nut 140 accommodating the "wide" travel distance by continued closing travel of the contact-actuating arm 114. Thus, Fig. 7 illustrates the closed-circuit ~-positlon of the lnterrupter device 7 with the operatlng magnet 57 energlzed and the compression spring 128 provlding the desired contact pressure ln the closed-clrcult posltion of the devlce. ~-It wlll be obvious that durlng the openlng opera-tlon, the operating shaft 69 will rotate in a counterclock-wlse direction, as vlewed in Fig. 7, carrying downwardly with - . . .
it the two operating arms 114 and 116 together with the cross-bar 112 and the three insulator supports 120. Also . . ~.: ~
carried downwardly will be the abutment plates 122 and the -contact pressure studs 142 until the overtravel ad~usting nuts 140 engage the yoke portions 130 of the contact actuating - arms 105, as illustrated in Fig. 9 of the drawings.
.
~- Assumlng that there does not exlst a welded condltion at the separable contacts 138, 139, the operating mechanism 144 will ~ ~ .
contlnue its counterclockwlse openlng movement carrylng the 20 separable contacts 138, 139 to thelr fully-open clrcult - position, as lllustrated ln Flg. 9 of the drawlngs.
. ~ . .
The interrupter unit 103 may be of any sultable type manufactured commercially by a number of companles, and, ln general, comprises an evacuated envelope 145 having end metallic plates 146, 147 hermetlcally sealed to the ends of the insulating envelope 145 ~ such as a ceramic sleeve, for example. The vacuum "bottle" 103 ls provlded havlng support-lng stud portions 149, say three in number, for example, . . .
; extending upwardly and downwardly, as illustrated in Flgs. 7 and 9, and also havlng the movable contact stem 150 extending . - . .: . -.
,.- . . :
43,102 ' - ' 366~4 externally, as illustrated ln Flgso 7 and 9. In lts manu-factured component assembly form, lt 1R, therefore, provided ~;
ln a form enabllng lts ready mounting by the six mountlng studs 149 and the movable contact 139 may be opened and closed by an actuatlng clamplng portion 152 secured to the extending end 150a of the movable contact stem 150. The present equip-ment utilizes preferably, one of these manufactured "bottles"
1~3 for each pole-unlt 39, 41, 43. As lllustrated in Flg. 6, there ls provlded an upper interrupter support castlng 154, cast, ln thls partlcular instance, of aluminum, which has a horlzontally-extendlng apertured support-flange portion 154a havlng mounting poles 154b therein to accommodate the three upwardly-extending mounting studs 149, the latter, as mentloned, constltuting a part of the manufactured bottle 103.
Mountlng nuts 156 threadedly secure the support- -flange portlon 154a of the casting 154 to the vacuum "bottle" -103 and maintain it flxedly in a proper position. The . .
casting 154, in addition, has a pair of downwardly-slanting support arms 154c, which are interconnected by a second supporting flange portion, or yoke portion 154d, the latter being affixed to an upper insulator support 158 (Fig. 6) and to a metallic conductor support strap 160, the latter belng securely mounted to an upper fuse-flnger terminal assembly, generally deslgnated by the reference numeral 162, and illustrated more clearly ln Fig. 6 Or the drawings. As . :~ .. , illustrated in Fig. 11, ~he fuse-finger assembly 162 accom-modes a power fuse 164 for each of the individual pole-units 39, 41, 43 of the equlpment 7. A fuse-finger contact-pressure spring 166 is utillzed, as illustrated in Fig. 6, ' 43,102 . ~ ',.
~)36~44 ~:~
.
supported between the pivotal fuse-finger portion 168 of the ~
terminal assembly 162 and a spring seat 170 associated with -a mounting bolt 172, the latter extending through a vertically-disposed insul spacer block 174, the latter being secured by mounting bolts 172, 176 to a laterally-extending insulatlng suport plate 178 of the fram 180. In addition, a metalllc angle 181 is provlded to rigidly lnterconnect the horizontally-extending line-connectlon strap 160 with the horizontally-extending conductor strap 182, Fig. 6 again . . .
showing this construction more clearly. A mounting bolt 184 extends vertically through the several component parts, as also shown in Fig. 6.
Fixedly secured to the upper extremity of a line- -~
connection strap 160 is a terminal clamp 186 havlng a ~
clamping portlon 186a whlch encircles the upper extending end 188 of the stationary contact stem 189, as more clearly :; shown ln Fig. 7. Due to the inherent flexlbllity provlded .... . ..... ..
by the line-connection strap 160 (Fig. 7), there ls not exerted any stress nor torqueing action upon the ~tationary contact stem 188. However, with reference to Fig. 7, it will be observed that the bottle structure 103 itself is rlgldly supported by the relatlvely masslve and heavy upper lnter-rupting casting support 154.
To counteract the lnward closing force exerted because of the evacuated environment 190 wlthln the evacuated enclosure 145, a klckout spring 192 ls provlded to compensate ; for the atmospheric pressure, the latter, of course, tending to force the separable contacts 138, 139 lnto the closed-circuit position, as illustrated in Fig. 7. The kickout ; 30 spring 192 ls interposed between a lower metallic washer 193 :'`. ' -.
- , - - - - - . - . . . . . . . . .: .
` 43,102 ,' ' ~'' ~` ~Q36644 and the upper end of contact operator 152.
With reference to Figs. 6, 7 and 9 of the drawlngs, lt wlll be observed that there is provided at the lower end of the contactor-assembly 7 a reverse-current connector-assembly 126 comprlsing a generally loop-shaped flexible connector 195 having an upper terminal 196 fixedly secured by a connector bolt 197 to the lower end of the movable contact operator 152. The flexible connector 195 extends rightwardly, as viewed in Fig. 7, into a loop portion "L", and then extends toward the left, as viewed in Flg. 7, to be secured by a connector bolt 199 to the mid-portion 200 (Fig. 12) of a stationary U-shaped current-feeding member `4 :.
generally designated by the reference numeral 201 and having a configuration more readily apparent from a study o~ Flgs.
1?-14 of the drawings. ~ -- With reference to Fig. 16 of the drawings, lt wlll ~- be observed that placlng the load-connectlon feed member 203 toward the front of the contactor assembly is commercially ~; inappropriate. Also, as set forth in Flg. 17, providing the constructlon as set forth therein~ with a relatively close spacing "S" between the stationary portlon 205 of the reverse-current loop-connector 207 and the feed-strap member 208 provides an undesirable neutralizatlon effect, as determined by the distance "S" ln Fig. 17.
The more deslrable form is as indicated in Fig. 18 of the drawings, where the current-feed structure 201 comprises a pair of stationary L-shaped leg members 210, 211 bolted, as at ; 212, to the side walls 214, 215 of the lower interrupter -~
casting support 216, and having a bight portlon at the front thereof, deslgnated by the reference numeral 200. The bight "'''., .;
` 43,102 ~036~44 portlon 200 is electrically connected to the lower termlnal 198 of the loop-shaped reverse-current loop assembly 126, as lndicated more clearly ln Fig. 9, whlch has the deslrable advantage, as seb forth in Flgs. 21 and 22 of the drawings, -- namely an augmentation of the upper movable flexible strap -portion 219 by the magnetlc field around the leg portlons 221, 222 of the U-shaped reverse-current feed structure 126.
It wlll be observed that the reverse-current loop force "F" acts to break contact welds when the magnet structure 57 is de-energized, as is the condition set forth in full lines in Fig. 20 of the drawings. Under this particular state of affairs, the force "F" acting is such ' as to create a fulcrum point at the pivot point lOi, thereby ``
tendlng to create a counterclockwise rotative action upon the reverse-current arm 136, thereby bearing agalnst the abutment plate 122, and asslsting the acceleratlng sprlngs ~ s 128 and the operating mechanism 144 in effecting a separation of the contacts 138, 139 within the vacuum-interrupter 103.
By avoiding the utillzatlon of relatlvely-heavy springs, which ln and of themselves would be ¢apable of breaking welds, avoidance of a heavy operating mechanism 144 is advantageoùsly obtained. That is, if relatively heavy ;; ~-~
accelerating springs 128 are utilized, it would take a con- ;
siderably stronger operating mechanism 144 to effect their compression, and thereby bring about the closed-circuit con-dition of the contactor assemblage 7.
In the closed-circuit position of the interrupter, as shown in Flg. 18 9 with the operating magnet 57 energized, the fulcrum polnt ls relocated so as to effect a desirable increase of pressure at the separable contacts 138, 139 ` 43,102 ~.~)3664~
during the attainment of heavy-fault current conditions. At thls time the fulcrum point ls at the movable contact plvot pln, as designated by the rererence numeral 132 ln Flg. 18. --Wlth reference to Flg. 11, the flow of electrical power through the starter 3 can be traced by referrlng to Fig. 11, where the starter 3 is shown in the energized position. The line stab assembly 19, mounted at the back of the cabinet 2 also serves as the starter line terminals Ll, L2 and L3. The stabs themselves are engaged by the fuse ~aws 223 of the lsolation switch 3 which is mounted on rails at the top of the cablnet 2. The llne ferrules 224 of the Type CLS power fuses 164, cllp into the fuse ~aws, and the load ferrules 226 fit into the fuse holders 162 which are part of the contactor line terminals. Power flow through the contactor 7 is from the load ferrules 226 of the power fuses 164, through the interrupter contacts 138, 139 shunt 195 and then to the contactor load terminals 45. The con-tactor 7 is mounted on rails 53 in the lower part of the ;
cabinet 2, immediately ad~acent to the current transformers 27, which are bolted to a panel 9 1n the side of the cabinet2, with the }oad terminals 21 for the starter 1.
Spring-loaded contact ~aws 228 (Fig. 6) mounted on the contactor load terminals 45 plug into a lower stab assembly 21, provlding a convenient connection to the motor load terminals Tl, T2 and T3.
Electrical protection ls provided by the Type CLS
power fuses 164 and by the overload relay 230. The CLS
current limiting power fuses 164 have a speclal time/current characteristic for motor service, and this characteristic is coordinated with the characteristic of the overload relay 230.
~''`'. '~
~~ 43,102 '' . , , . ' 11~36644 Currents greater than full load motor current, up through locked rotor current, will operate the overload relay 230 and trlp the contactor 7 before the fuses 164 blow. This prevents unnecessary blowlng of the fuses 164. Since the lnterruptlng capaclty of the contactor 7 is 50,000 KVA, the power fuses 164 must operate faster than the overload relay 230 when current exceeds thls value, ln order to prevent damage to the contactor 7. In all faults above 50,000 KVA -and wlthin the ratlng of the equipment, the CLS fuses 164 will operate flrst.
The current transformers, overload relay heaters, and power fuses are coordlnated wlth the motor characterlstlcs, so that the starter 1 must be used wlth the motor for whloh ;,, . :. . ' lt was designed. Motors wlth special character~stic or loads requlring special protectlon often require other or additlonal protectlve relays.
j Vacuum contactors are relatlvely new on the market '~ and have en~oyed only llmlted success dur to several short-. .
comlngs.
In an efrort to mlnlmize the most ~erious of the~e shortcomings, the vacuum interrupter manufacturers have found lt necessary to use contact materlals whlch are susceptlble to welding.
; The weldlng problem, however, can be minlmlzed by the use of contact and weld breaking forces approximately ten tlme~ those usually found ln a conventional alr break contactor , :
of comparable rating.
, Vacuum lnterrupters havlng the most deslrable ,.......................................................................... .
lnterruptlng characterlstics and longest contact life have been found to weld at currents considerably below their . . .
43,102 ':
lnterruptlng llmit, so the lnterrupting rating of a contactor uslng these lnterrupters is limited by the ability of the actuating mechanism to overcome the weldlng problem rather than by the arc interrupting ablllty of the lnterrupter.
A three-pole contactor havlng a magnet and frame assembly proportloned to meet the design requlrements of the requirements of the vacuum interrupter and still have a -reasonable mechanical life would be much too large and costly to compete with exlstlng alr-break contactors whlch - 10 requlre only a fraction of the contact force. As a result of this "squeeze," presently avallable vacuum contactors are a deslgn compromise which do not completely satisfy the requlre-ments of the vacuum lnterrupter and as a result do not perform as well as exlstlng alr-break contactors.
The very hlgh contact forces mentloned above are requlred only when lt ls necessary to obtaln the maximum momentary rating of the vacuum lnterrupter whlch is ln the event of a power system fault. Slnce the contactor may seldom see thls condltion ln a¢tual servlce, a contactor designed to -- 20 contlnuously provlde these hlgh forces would represent a rather lnefflclent use of space and materlal.
A reasonable-slzed magnet coupled to the lnter-rupter shaft through a toggle mechanism or other system of levers could be advlsed to develop hlgh contact force, but -the hlgh mechanlcal advantage of this mechanism would act to reduce the contact operating speed far below the values ~ ~ .
recommended for the vacuum lnterrupter. The hlgh mechanlcal advantage of this mechantsm would, ln addition, result in low contact overtravel whlch in turn would make frequent adjustment of contact overtravel necessary. ;~
. ,~ ' .. ' .
43,102 .', '.
. .
lQ36644 Reverse current loops slmilar to the one shown in Flg. 15 have been employed in the past to increase contact force under heavy fault conditions, but have the tendency to override the operating magnet. A reverse current loop 232 (Fig. 15~ of this type, designed to supply the required contact forces of a three-pole vacuum contactor, would exert so much force that the reverse current loop 233 would hold the contacts and magnet closed even after the magnet is de-energlzed. A weak reverse current loop 233 of this type would not hold the contacts closed, but would act to reduce opening speed and weld-breaklng forces, which is also unde-i slrable.
In the disclosed vacuum contactor design 7 (Fig. ;~ ;-20), contact sprlngs, operating magnet and contactor frame details are proportioned to provide contact forces sufficient to insure satisfactory performance under startlng, running, and locked-rotor conditions for the maximum size motor with which the contactor 7 will be used.
These are the operating conditions the contactor 7 wlll see in everyday service, and the mechanical forces which the operating mechanism must be able to endure Por a million or more operatlons.
; Occasionally the contactor 7 may, however, be sub-~ected to power-system fault conditions in which event the contactor 7 may be called on to interrupt or withstand peak currents 10 times or more the maximum peak currents en-- countered in everyday service under locked-rotor or motor-... .
startlng conditions.
In order to handle these higher currents, the vacuum interrupter 103 will require much higher contact and ` ` 43,102 :`
' la36644 weld breaking forces than were necessary for handling the normal motor currents encountered in everyday service. ;
To obtain the higher mechanical ~orces only during an occaslonal system fault, without increasing the mechanical forces in e~ect in normal operation, a novel reverse current loop ls provided as shown in Fig. 20.
This reverse-current loop 126 provides an increase in contact force and also weld-breaklng force which is in proportlon to the square of the current "I" flowing through the reverse current loop.
By properly proportioning the reverse-current loop ~, 126, it is possible to provide a substantial increase in the contact and weld breaking forces under hlgh-current conditions -while only slightly increasing these forces under normal operating conditlons.
The reverse-current loop 126 consists of upper and `~
lower shunt legs 221, 222 plus parallel load connectlon bus bars 210, 211 as shown in Figs. 12 and 20.
When current flows through the reverse current loop conductors 221, 222, the magnetic fields surrounding these conductors 221, 222 react with each other to develop mechanical forces on the varlous conductors.
The lower horizontal leg 222 of the shunt and the ,!
parallel load connection bus bars 210, 211 are restrained by '' non-movable parts of the support structure 180, while the ' ; :,:
,; upper shunt leg 221 is free to move upward until it strlkes ~; -' the right-hand end o~ the reverse-current loop-arm 136.
When the contactor 7 is sub~ected to a power system fault, of high current magnitude, the reverse current loop 30 126 will apply a force upward on the right-hand end of the ~ ;
. ~ .
`` 43,102 ~ i ' , -1~3669~
- reverse-current loop-arm 136 which will in turn pry the inter- -rupter contacts 138, 139 closed as shown ln Flg. 17 assuming the contactor magnet 57 remains closed.
A second reaction of the reverse-current loop-arm 136 is to apply a downward force on the contact spring support plate 122 which wlll in turn increase the openlng veloclty of the magnet and cross-bar assembly 112 once the magnet 57 is de-energized.
When the magnet 57 is released, the moving assembly ls accelerated by the comblned forces of the contact springs 128 and reverse current loop 126 until there is no gap at the ; contact overtravel ad~ustlng nut as shown ln Flg. 20.
At this point, the klnetic energy of the moving system imparts a hammer blow to the contact actuating arm 105 ~ which acts to break any contact welds which might exist.
- When the overtravel ad~usting nut 140 makes con-tact wlth the upper contact spring seat 130, as shown in ^ Figure 20, the function of the reverse current loop 126 automatically takes a complete reversal to apply an additional contact openlng force to the lnterrupter 7 rather than a con-tact closlng, as lt prevlously had done when the magnet 57 was closed.
Use of a flexible shunt 195 doubled back on itself in a conventional manner as shown in Fig. 16 brings the load , connection 203 out the front of the contactor, which is undesirable for use with plug-in devices.
Doubling the load connection back under the lower leg of the shunt 195 as shown in Fig. 17, acts to weaken the magnetic fields and mechanical forces o~ the reverse current loop 207 unless dimension "S" is made relatively large.
''' '~ ' '''' ` 43,102 .
~(~36644 The disclosed design employs a novel arrangement of the current-carrying parts 210, 211 of the reverse current loop 126 which makes it possible to bring the load connections 45 out at the rear of the contactor 7 and at the same time increase rather than decrease the ~orce o~ the reverse current loop as shown in Fig. 22.
In this design the connection ~rom the contactor load terminal 45 to the lower leg 222 of the shunt 195 is dlvided into two parallel legs 210, 211 which straddle and are mounted at the same elevation as the upper leg 221 o~ the shunt.
The magnetlc fields of the two parallel connections 210, 211 to the load terminal 45 combine with the magnetic fields surrounding the shunt 195, as shown in Fig. 22 to shape and to strengthen the resulting magnetic field of the ' reverse current loop 126 in such a manner that the net .;. ,'. ::
s reverse-current loop force "F" ls greater than for the con-.~ ,~ . ..
ventional reverse-current loop shown in Fig. 16. ~`
- A kickout sprlng 192 ls mounted directly on the `
contact shaft 150 of the interrupter 103 to take up the play ~; between the contact actuating mechanism 144 and the interrupter `
contacts 138, 139. Without a kickout spring 192 in this lo-cation, the contacts 138, 139 could touch momentarily under low contact force conditions while play is being taken up in the operating mechanism 144. Play between the contacts and operatlng mechanlsm 144 would aggravate the contact erosion and weldlng problems both on the opening and closlng operations.
The kickout springs 192 also minimize armature bounce on openlng and in addition are proportional to apply ~ ~3~ `
: ' ',;
: ' ' ` 43,102 :
:
1(~;31~;644 :
sufflcient load on the magnet 57 at open gap position to prevent the magnet 57 from picking up unless its operating voltage is sufficlent for the magnet 57 to seal-in from the contact-touch posltion.
Each pole 39, 41 and 43 of the contactor may be installed or removed from the contactor as an individual sub-assembly, so that it may be efficiently assembled or main-tained at a work-beach rather than ln the contactor 7.
. .
; The interrupter unit itself may also be installed or removed from the contactor as a smaller sub-as~embly con-sisting of the interrupter 103, its support 154, moving contact actuating arm 105, and reverse current loop details 126 as shown in the exploded view of Fig. 10.
In order to obtain maximum mechanical life of the interrupter bellows 235 and also avoid friction between the interrupter contact shaft 150 and its bushlng, it is important , that the relatlonship between the contact drlve pin 132 and the plvot pin 107 for the contact actuating arm 105 be ; accurately maintalned.
To accomplish this, the lnterrupter 103 and the ,. . .
.; contact actuating arm 105 are both mounted on a single rlgld .; . .
mechanlcal detail 110 which can be accurately manufactured.
This detail 110 is the lower interrupter mounting bracket shown in Figs. 28-30.
In connection with the above allgnment of parts, it is also desirable that the contacts 138, 139 touch when the contact drive pin 132 ls on the same horizontal center-line 237 as the plvot pin 107 for the contact-actuating arm 105.
When the interrupter sub-assembly is being -31~
`'~' .
. . . ~
~ 43,102 ~lJ3664~
assembled, the kickout spring 192 is placed over the contact shaft 150 and then compressed by the contact operator 152 which ln turn is held in place by the shoulder bolt 239. The - shoulder bolt 239 is only tightened finger tight so as not to apply excessive torque to the interrupter shaft 150 and bellows 235.
The contact operator 152 and shoulder bolt 239 . design is coordinated ln a manner that the shoulder bolt 239 cannot clamp the contact operator 152 to the contact shaft :
150, but instead permits the contact operator 152 to rotate , freely on the contact shaft 150 without applying torque to ~. .
the contact shaft 150 when the contact operator 152 is being ~ .
,. lined up with the contact-actuating arm 105. `
After the contact drive pin 132 is installed, the contact actuating arm 105 is depressed to take up the play ~ ~
; between the contact drlve pin 132 and contact shaft 150 .;
~: .
; following which the contact operator 152 ls clamped to the contact shaft 150 by tightening the clamplng bolt 241. ;:
; In normal servlce, the contact shaft 150 wlll be ;~
actuated through the clamped ~olnt between lt and the contact : .
: .
operator 152, but should this ~oint fail the contacts 138, 139 will then be closed by compression of the parts between the drive pin 132 and the end 150a of the contact shart 150, ~:
and opened by the shoulder bolt 239.
One of the ob~ects of the present invention ls to ,.
prevent excessive torque from being applied to the shaft 150 :~
of the interrupter 103 during malntenance and/or assembly :~
since torque may destroy or shorten the mechanical llfe of .
the interrupter bellows 235. :-The shoulder bolt 239 acts as an assembly fixture : -32- -.' '~ .
` 43,102 ..
~' : ~36644 to compress the kickout spring 192 durlng assembly while still allowing the contact operator 152 to be rotated as ~:~
required to install the contact drive pln 132. In operation the shoulder bolt 239 in addition acts as a safety device :;~
to insure opening of the contacts ln the event the contact - operator 152 ls not securely clamped to the lnterrupter con-tact shaft 150. -~
' The interrupter 103 is rlgidly supported at its . upper end, which contains the interrupter stationary contact `.......... 10 138 so as to avoid transmitting contact forces through the walls 145 of the lnterrupter 103. The moving contact end 150 of the lnterrupter 103 in addition is clamped to the statlonary portion of the pole assembly to provide lateral ::-stability. Clamping of the lower end of the interrupter sub-assembly "SB" is accompllshed by means of an oversized ~ open slot 243 whlch compensates for the manufacturlng '~; tolerances of the interrupter 103 and also simpllfies instal-lation and removal of the interrupter sub-assembly "SB".
Manufacturing tolerances on the interrupter length dimension "X" are rather large, so khe vertlcal locations of the lower ends of the lnterrupter 103 may vary considerably : from contactor 7 to contactor 7 and from pole to pole. Since the operatlng mechanlsm 144 for each pole is mounted on the moving contact end "E" of the indlvidual interrupters 103, rather than on some fixed portion of the pole assembly, thiS : `
is of little consequences. - ~ .
;~ In the event the interrupter length "X" is found to be other than lts nominal value, the final lengths of the con-tact springs 128 will also vary from their nominal value resulting in elther h~gh or low contact forces.
;: -33-~; ;
` 43,102 , , ~036644 The average contact force in the case of a multlple-~` pole contactor~ as shown ln the drawings, can, however, be corrected by adJusting the angular position of the magnet armature 61 on the operatlng shaft 69 so that the correct - average contact spring length and force 128 is obtained when the magnet 57 ls sealed-ln. ` -Angular posltion ad~ustment of the magnet armature 61 is a standard ~eature of an existing air-break contactor magnet 57 applied to the disclosed vacuum contactor 7.
Variatlons in contact ~orces between poles existing after the magnet ad~ustment 61 has been made will fall within allowable limlts lr the contact springs 128 are designed to have a low spring rate.
NON-TORQUE ACTION EXERTED BY SHOULDER-BOLT 239 ~;
To avold lmposing torque action upon the movable contact stem 150 and thereby exerting corresponding torque action upon the bellows 235, the utllization of a novel shoulder-bolt 239 ls provided. The construction of the shoulder-bolt i8 set forth in Figsi 9 and 23 of the drawings.
It wlll be observed that the bore 245 of the contact-shaft operator 152 has a relatively loose fit on the contact stem 150 as shown in Flg. 23, the shank 239a of the shoulder bolt 239 has a loose fit at "Ct' wlth the movable contact operator 152. The shoulder-bolt 239, for example, may have an Allen hèad wlth an enlarged portion 239a and a reduced portion 239b with a shoulder 247 therebetween, so that the shoulder-bolt, ` when tlghtened, will ~orce washers 249 (Fig. 10) against the lower extremity 150a of the movlng-contact shaft 150 of the vacuum-type interrupter 103. Th1s is shown in Fig. 23. The .. . ..
number of washers 249 is arranged to accommodate the .. ~ .;.. :, ; -. . .. .
43,102 , 1~36644 tolerances provided between the different movable contact shafts 150 of the several pole-units 39, 41 and 43. Once the shoulder-bolt 239 is tightened, the contact-shaft operator 152 ls moved manually upwardly, so that there is no clearnace at the polnt"D" in Fig. 23. Then the clamping bolt 241 of Fig.
: 10 is tightened, so that the movable contact shaft 150 is operated by the contact-shaft operator 152, the latter having the apertures 250 provided therein to accommodate the center-line of the contact-drive pin 132. As a result, there is no torque action exerted either upon the movable contact shaft 150, or the bellows 235 located interiorly of the vacuum envelope 103. There may, of course, be relatively wide tolerances provided in the vacuum-bottle manufacture, and the foregoing arrangement permits a desirable accommodation of these tolerances.
~: VACUUM-BOTTLE TOLERANCES
Due to the wlde latitude of the tolerances provided in the manufacture of the vacuum bottles 103, it is desired not to impose any stress upon the ceramic envelope 145, or to effect the breakage of any of the hermetlc seals 251. To effect this end, an accurately-machined lower-interrupter support-plate 110 having the pivot apertures 252 provided .
therein is supplied. These pivot apertures 252 may be accurately machlned, and once the vacuum bottle 103 is fixedly secured by the upper interrupter castlng 154, as a first operation, subsequently, as a separate operation3 the U-shaped accurately-machined support plate 110 is secured into place by the lower three mounting bolts 149. The pivot-pin 132 may then be accurately located with respect to the lower interrupter support 110 because of the accurate machining .
43,102 .
1~:)3~6~4 -:
of the pivot apertures 252 therein.
Thls wlll accurately locate the contact-actuatlng , -lever 105 and, addltlonally, accurately locate the contact- ~:.
stem drlvlng pin 132. As mentioned previously, the contact-shaft clamp bolt 241 i5 tightened as a flnal operation after prevlous assemblage of the contact-pivot pin 132 and tightenlng of the shoulder bolt 239.
WIRING CIRCUIT DIAGRAM FIG. 34 Included ln the wiring clrcuit diagram of Flg. 34 ~;
ls a power-operated main contactor 7 wlth separable power contacts 138, 139 to connect the three-phase load-llnes Tl,~ :
T2, T3 to the power-line conductors 254, 255 and 256, whlch are normally connected to the main supply lines Ll, L2 and L3, through a disconnecting or isolating switch 3 including an arrangement of main power fuses 164 and sets of comple-mentary dlsconnecting contacts 223 (Fig. 11).
Contactor 7 includes an electromagnetic operator .; ::
57 havlng a coil 59, which is energized by a rectifier 259 in responqe to the operation of a normally-biased-open push-button "START" switch 261. Closure of the "START" switch 261 energizes a relay 263 whose normally-open contacts 265 and 267, respectively, connect the output of the rectlfier 259 to the operator 59, and the input of the rectifler 259 to the . .
secondary 269 of a stepdown transformer 44, whose primary 271 ls connected across one phase of the main power-lines Ll, ,: .
L2 and L3. The input to the primary 271 includes fuses 273.
The electromagnetic operator 263 of the contro~ re-lay i8 normally energized from the transformer secondary 269, "-;but may also be energized by a separate source of control power 275 for test purposes.
:~ :
. . - ~ .
, , - . ~ , . .. . ~
` 43,102 .
~: lQ36644 ;:
Included in the output circult of rectifier 259 are the -normally-open contacts 265, male-female type plug disconnects 277, and resistor 279 shunted by a delayed-break auxiliary contact 281 mounted on the magnet assembly 57.
A hold or latch clrcuit 283 is shunted across the "START" button 261 and in¢ludes male-female plug-type discon-nects 285 and normally-open contacts 287, which are operated to close thy circuit 289 across the "START" button 261 when contactor 59 is operated, thereby holding relay 288 and con-sequently contactor 59 ln the operated energized condition.
When contactor 7 closes, delayed-break auxiliary contact 286 openB to insert protectlve resistor 279 in series with the holding coll 59.
The thermostatic switch 290 is an overload switch and responds to the overload current conditions Or the load lines Tl, T2 and T3, as manifested in the heating of resistors ` (not shown) energized respectively from the current trans-formers 27.
From the foregoing description lt will be apparent 20 that there has been provlded an improved operating mechanism for the separable contacts of a circuit-interrupter, parti-cularly applicable to one Or the vacuum-type. Although the instant invention has been described in connection with a vacuum-type circuit-interrupter 10 3, it will be obvlous to those skilled in the art that certain principles, involved in the present disclosure, are pertinent to many other types of lnterrupter units, say those of the air-break type, such as illustrated in Figs. 35-37. In these figures, gas-evolving materials are utillzed instead of an evacuated environment.
,~ 30 However, the desirable conditlons for effecting the breaking . . . - . - . . ~
.
43,102 ~.
~ lQ36644 ;~ ~
o~ welds, or the addition of contact-pressure spring-force in the closed-circuit position of the lnterrupter, when the magnet ls energized, is accomplished in a manner similar to that described heretofore.
Wlth referenct to Figs. 35, 36 and 37 lt wlll be -` observed that there is provided an air-break circult-interrupter 300 havlng a hollow movable contact 301 pivotally connected, as at 132, to the movable contact-actuating arm 105 in a manner ~imilar to that heretofore described in connectlon with Flgs. 6, 7 and 8 of the drawings. The movable contact 301 makes separable contacting engagement wlth a statlonary contact member 303. The movable contact 301 moves downwardly durlngthe openlng operatlon through a generally tubularly-shaped member 305 ~ compo~sed of gas- -evolvlng material, such as flber, Delrln, Celcon/ or llke gas-evolving materlals, as deslred. In addltlon, a follower member 310, more clearly shown in Flg. 36, ls secured by a metalllc rod 312, as at the pivotal pln location 315.
; Durlng the openlng operatlon, as in the manner 20 hereto~ore descrlbed ln connection wlth Fig. 7, the movable tubular contact 301 moves downwardly carrylng wlth lt the plvotally-mounted follower member 310, the latter also belng composed Or gas-evolving materlal. An arc ls establlshed, and the arc ls extlngulshed by the gas evolutlon resulting from the interaction between arc and the surrounding gas-evolving materials. An annular coil 320 may be electrically ; lnterposed between the relatively stationary annularly-shaped contact 303 and a lower-disposed arcing plate 325 to provide a radial magnetic fleld to bring about the rotation of the 30 established arc, and consequently a more intimate engagement ' ' .
` 43,102 ~03~644 thereof with the surrounding gas-evolving material definlng an annular arcing 330 chamber. As will be obvious from an inspection of Fig. 37, the annular arcing member is provlded between the outer surface of the insulating follower member 310, composed of gas-evolving material, and the inner surface of the surrounding insulating cylindrical member 305 also composed of gas-evolving material, as mentioned.
The mechanism 144 may be of the same type as here-tofore described in connection with the vacuum-interrupter 1( 103. Also, in the closed-circuit position of the device, with the contacts 301 and 303 in a welded condition, again the augmentation of the reverse-current loop-arm assisting the operating mechanism 144 is desirable in breaking any welds established at the separable contacts 301 and 303.
; Certain addltional details regarding the inter-rupting structure only of Figs. 35 and 37 are set forth in United States Patent No. 2,294,801, lssued September 1, 1942 to Herbert L. Rawlins, and assigned to the asslgnee of the instant application.
Also, it will be observed that with the lmproved operation mechanism, and the reverse-current loop system, the function of the reverse-current loop-system changes in dependence upon wheteher or not the oepratlng magnet 57 is energized, or is not energized. In the energized state of the operating magnet 57, an addltlonal force ls provlded to malntain the contacts 138, 139 closed durlng the exlstance of heavy-fault-current conditions. When the magnet 57 is not energize~,the fulcrum point changes, or is relocated to there~y provide, instead of a closing force, in this instance an opening force, which assist and augments the accelerating ' ~ ~ ; -,~ :
~ 43,102 16)36644 opening springs. -~ :~
Although there has been illustrated and described ~::
speciflc embodiments of the lnvention, it is to be clearly understood that the ~ame were merely for the purpose of illustration, and that changes and modifications may readily be made therein, by those skilled in the art, without departing from the spirit and scope of the invention.
.
, ~.
., ~
.. .. . ..
, .~ .
'~.'~' ''. '' ' ' , . .
,. ., .:. -': .
:, . ' .
''' `.,: .
,~ :
. ~ .
.. ' ;'', ' " '. ' :' .. ,i :
.': ' :
.
43,102 -~3~ ~;
relocation of the fulcrum point of the reverse-current actuatlng arm and thereby drastically change the operatlng function of the reverse-current loop system to thereby result in an entirely oppositely-dlrected force, this time a force directed to open the separable contacts and thus to break any ;-welding condltlons existing thereat. `
In the lmproved operatlng mechanism of the instant ~-invention there ls associated with the rotatable contact-operating arm an abutment member, such as a plate, for example, which ls associated with the contact-pressure spring, and a reverse-current loop arm pivotally mounted to the contact-actuating arm has a nose portion bearing on said abutment member or plate, and operable during the de-energized conditlon of the magnet to act in an opening directlor. against sald abutment plate, and have lts fulcrum point at the pivot-shaft location between the contact-actuating arm and the movable contact stem. Thus, magnetic forces are brought lnto play to redirect the reverse-current loop effect, and to pry, in effect, .. .
the welded contacts apart, and thereby asslst the opening accelerating springs of the circuit-interrupter or contactor.
In more detall, the reverse-current loop system of the present lnvention comprises a metallic conductlng arm carrying the line current to the interrupter contacts, and , . ..
` pivotally mounted on the same plvot shaft location at which the rotatable contact operating arm pivotally connects to the movable contact stem of the vacuum-interrupter. By thus ~ belng pivoted to the movable contact stem with the rotatable ; contact-actuating arm during heavey-fault current condition, the magnet repelling effect between the sldes of the loop ~-forces the separable contacts more firmly closed under high-' -6-` 43,102 , 1~3664~
fault condltions, when the magnet ls energlzed, as ls desired.
On the other hand, durlng the opening operation, when the operating magnet ls de-energized, and thy operating mechanism is stalled at the contact-touch point, due to a welded condition exlsting at the separable contacts; or in other words, the contacts are, in fact, welded closed, the reverse-current loop arm acts ln a manner to break the con-tact weld by relocating the fulcrum point, of the reverse-current actuatlng arm so thRt it now exists at the pivot : 10 polnt for the rotatable contact aPm with the movable contact stem.
Another very important feature of the present invention is the structure for supplying or feeding series current to the reverse-current loop arm, so that it does not oppose or tend to neutralize the magnetic action of the reverse-current loop arm. This is achieved by a speclal ~. stationary current-feed clrcuit, which locates the current-feeding arms in roughly the same plane as the movable portion o~ the reverse-current loop arm, so that, the fact, the `~ 20 magnetic effect, generated at the two sationary current-feed arms, is to increase and augment the magnetic effect . .
exerted on the movable portion of the reverse-current loop-. ~ , ,.
- arm structure.
BRIEF DESCRIPTION OF THE DRAWINGS ~ ~ :
Fig. 1 is a perspective vlew of motor-starter equip-~ ment including two motor starters disposed in superimposed ~ relation together with their disconnectlng-swltch structures;
, .
Fig. 2 is an enlarged vlew looklng lnto the interior of a cell-structure adaptable for accommodatlng the improved ~ ;
30 roll-in vacuum-type circuit-interrupter structure of the : , .:
-7- :
43,102 .
lQ36644 ~
instant inventlon, wlth the access doors for the low and hlgh-voltage compartments being open;
Flg. 3 is a side-elevational vlew of the right slde of the truck-mounted contactor, or interrupter assembly of the - lnstant invention;
Fig. 4 i3 a s~de-elevational vlew of the lefthand slde of the truck-mounted vacuum-interrupter assembly of the present invention;
Fig. 5 is a front elevational v~ew looklng at the ;~
, lO front of the truck-mounted vacuum-type circuit-lnterrupter ; assembly of the present lnventlon;
Fig. 6 is a vertical sectional vlew taken sub-stantially along the line VI-VI of Fig. 5 with the separable-contact structure closed;
Fig. 7 ls an enlarged detalled vlew of the oper-atlng llnkage and mechanism structure of Fig. 6, again the ~ ~-separable contacts of the vacuum-type circuit-interrupter assembly belng lllustrated in the closed-circult positlon with the operatlng magnet energized;
Fig. 8 ls a fragmentary vertlcal sectlon view taken substantlally along line VIII-VIII of Fig. 7, again the con-tact structure belng shown in the closed-clrcult positlon;
Flg. 9 ls a vlew slmllar to that of Fig. 7, but lllustrating the separable contacts of the vacuum-lnterrupter `~ unlt ln the fully-open ciruit position with the operatlng magnet de-energlzed;
Flg. lO is an exploded perspectlve vlew of the several parts employed ln con~unction with the lm~rovèd operating mechanism of the ln~tant lnventlon, Fig. ll i a ~omewhat diagrammatlc view of the com-43,102 lQ36644 ponent parts of a motor-starter equlpment for controlllng motor installations with the disconnecting switch shown closed, and also the contactor assembly being shown in the closed-circuit position, the truck-mounted elements being illustrated ln their in-cell operating condition;
Fig. 12 is a top plan view of the reverse-current ~eeder circuit illustrating the structure thereof;
Fig. 13 ls a side-elevational view of the reverse-!''' current ~eeder structure of Flg. 12;
Flg, 14 i8 a front elevational view of a component .
part of the improved reverse-current feeder circuit of Figs.
12 and 13;
Fig. 15 is a diagrammatic v~ew illustrating a single-actlng reverse-current loop structure with the contacts tnot - shown) closed, and electrical current passlng through the reverse-current loop structure;
;....... :,:
Fig. 16 illustrates diagrammatically a double- i;
acting reverse-current loop structure utillzing some of the principles of the present lnvention, but lllustratlng a con-dition Or a feeder connection structure, whlch is not com-.... ; . .
~ mercially approprlate or desirable, the contact structure ~ ...... . .
- (not shown) being lllustrated in the closed-circuit position, and again electrical current belng lllustrated as passing ~ ;
through the double-acting reverse-current loop; ~ ~;
Fig. 17 illustrates diagrammatically the improved relocation of the feeder circuit structure of Fig. 16, in which the double-acting reverse-current loop is adversely `
magnetically a~fected by the particular feeder circuit arrange-ment illustrated in Fig. 17, which is, of course, undesirable;
Fig. 18 illustrates diagrammatically the closed-.... .. . . . .. . .. .
43,102 ~Q3~;6~
circuit;posltion of the vacuum-type circuit-lnterrupter of the present invention, illustrating the passage of current -through the reverse-current loop, illustratlng the location of the pivot point or fulcrum point for the reverse-current loop arm, with the operating magnet energized, and durlng the exlstence of hlgh-fault current conditions existing in the !l separable contacts of the vacuum-type circuit-interrupter, the latter being lllustrated as in the cldsed-circuit position;
Fig. 19 is a sectional vlew taken substantially 10 along the line XIX-XIX of Fig. 18; -Fig. 20 illustrates a de-energized condition of the vacuum-type circuit-interrupter of Figs. 18 and 19, showing a relocation of the pivot point or fulcrum point for the reverse current loop arm structure, and the magnetic repulsive forces encountered, the view also illustrating the improved ~eeder-current connections to the reverse-current loop-arm;
. .
Fig. 21 illustrates a fragmentary sectional view taken along the line XXI-XXI of Fig. 20, lllustrating the current-flow conditions, and only showing the feeder-current connector system;
Fig. 22 is a sectional vlew taken substantially along the line XXII-XXII of Fig. 20 illustrating diagram-matically the magnetic lines of force associated with the improved feeder-current system of the present invention;
Fig. 23 illustrates a sectlonal view taken through the improved shoulder-bolt and movable-contact operator con-nection for actuating the movable-contact stem of the vacuum-type circuit-interrupter of the present lnvention;
Fig. 24 is an enlarged side-elevational vlew of the improved movable-contact operator utilized, -10- ;` ' '' '.' : ' , . . :. .. ~ - : . .
1~)36644 Fig. 25 is a side-elevational view of the improved - movable-contact operator of Fig. 24;
Fig. 26 is a top-plan view of the improved movable-contact operator of Fig. 2~;
Fig. 27 is an inverse plan view of the improved movable-contact operator of Fig. 24;
Fig. 2~ illustrates in side elevation the accurately-machined lower interrupter support-plate utilized in the present invention;
Fig. 29 is an inverted plan view of the accurately-machined interrupter support structure of Fig. 2g;
Fig. 30 is a side-elevational view o~ the improved accurately-machined interrupter support of Figs. 2~ and 29; ~
Figs. 31-33 are enlarged detail views of the top ;;
~ . . .
interrupter clamp for connecting to the stationary contact stem of the vacuum interrupter;
Fig. 3~ illustrates diagrammatically the wiring -.
diagram for the starter assembly of the present invention; and 'r; Figs. 35-37 illustrate an application of the mechan-.` 20ism to a modified-type of arc-interrupting structure.
` DESCRIPTION OF THE PREFERRED EMBOD ENT
.
The present invention has particular applicability ,` to high-voltage motor starters 1 designed for starting and con-... .. :~
trolling alternating-current motors. Generally, these ~ ~
..,.. ~, .
starters 1 are supplied in a steel floor-mounted enclosure 2, such as set forth in Fig. 1. The steel floor-mounted enclosure 2 may, for example, accommodate two motor starters 1, as actually shown in Fig. 1 disposed in superimposed relation.
As set forth in Fig. 11, each high-voltage motor-~.
starter apparatus 1 comprises a cabinet housing 2 in which high-voltage modular plug-in assemblies corresponding to an .' . ' -.~ . .
-~~ 43,102 ;, , lQ3~69~4 isolating-switch assembly 3, a power-fuse assembly 5 and a contactor assembly 7 are secured. The cabinet houslng 2 ls ,, illustrated in Flg. 2 as compr~sing panels 9-11 and supporting ; ,-structure 13 assembled to form a front-entry single-compartment ~
. .
cabinet with access provlded by hinged access doors 15 and ', 17. Mounted on the lnterlor surface of the back panel 10 .
are electrlcal terminal assemblles 19 and 21 whlch electrlcally engage an lsolating-switch assembly 3 and the contactor assembly 7, reQpectlvelyO The three-phase output power de-veloped by the hlgh-voltage apparatus 23 ls conducted through cables 25, which pass through current transformers 27 to a load terminal assembly 29 for connection to a remote electrical clrcuit (not shown). This clrcuit could, of course, be motor controlled equlpment. Secured,,to the interior surface of the right-hand panel of the cabinet houslng 2 ls the low-voltage clrcuitry 31, which is electrlcal-ly connected through sultable ~ransrormer means 33, to pro-vide safe access ~or monitoring the operation of the hlgh-voltage plug-ln assemblies.
~' 20 The hlgh-voltage motor-starter apparatus 23 of Flg.
11, for example, may require a slngle contactor assembly 7, and therefore supports the compact modular packaging scheme illustrated, ln which the modular assemblies 3, 5 and 7 can ,, be quickly removed from the houslng cablnet 2 merely by slid-lng the assemblles 3, 5 and 7 forward through the cabYnet opening provided by the access door 15.
The high-voltage motor-starter apparatus, sche- ' ~ '' matically illustrated in Fig. 11, is set forth, in detail, in - !' the follo~lng patents: U.SO Patent 3,602~680, issued August ~. . .
31, 1971 to Alfred W. Hodgson; U.S. Patent 3,639,873, issued ~-:.~ ,, ~ ' '.
- - ` 43,102 1~3~644 February 1, 1972 to Alfred W5 Hodgson; UOSo Patent 3,621,339, lssued November 16, 1971, to Alfred W. Hodgson; U.S. Patent 3,264, 431, issued August 2, 1966 to A. W. Hodgson; U.S.
Patent 3,264,432, lssued August 2, 1966 to A. W. Hodgson et al; , U.S. Patent 3,264,433 issued August 2, 1966 to R. D. Clark, Jr. et al; and U.S. Patent 3,290,468 lssued December 6, 1966 to R. D. Clark Jr. et al.
Sidewalls of the modular assemblies 3,5 and 7 cooperate ln an overlapping relatlonshlp in the cabinet housing 2 to define two cablnet compartments "A" and "B".
; Compartment "A" is deslgnated the hlgh-voltage component compartment wlth access provlded by door 15, and compartment "B" is designated the low-voltage circuitry compartment with ` access provided by door 170 As seen more clearly in Fig. 11, the isolation-switch assembly 3 comprlses a rotatable handle mechanlsm 35, which controls the positioning Or electrical contacts 37 to ; engage and to disengage electrical contact with the main power `~
lines which terminate at the electrloal tremlnal assembly 19.
20 The location o~ the isolation swltch assembly 3 ln the cablnet housing 2 ls selected to position the handle mechanism 35 at a convenlent operator height. ' ' The handle mechanism 35 ls described ln more detail ; `
in U.S. Patent No. 3,264,431 lssued August 2, 1966, and ; '~
assigned to the assignee of the present lnvention.
Access to the high-voltage compartment "A" is pre-vented''by an interlock system (not shown) when the handle mechanlsm 35 is in either the "OFF" or "ON" posltion. Access to compartment "A" is permitted when the handle mechanism 35 30 is rotated to a horlzontal positlon (not shown). A spring-i 43,102 ,:
, 1(~36644 loaded pin (not shown) must be manually depressed before the handle mechanism 35 can be rotated, thus preventing inadvertent isolatlon of the handle mechanism. Access to the low-voltage compartment "B" is provided by the door 17 regardless of the position Or the handle mechanism 35.
The contactor assembly 7 comprises electrically isolated contactor poles 39, 41 and 43 which represents - commercially-available components, such as the Westinghouse Electric Corporation contactor Type LF-50V430 contactor.
Contactor electrical terminal 45, as illustrated in Flg. 6, engages electrical terminal assembly 21 to supply voltage through the cables 25 to the remote load, which may be a motor lnstallatlon.
The lsolation switch assembly 3 ls slidably i' positioned within the cabinet housing 2 by outwardly-protrud-ing flanges which engage horlzontal guide tracks 47 (Fig. 2).
Due to the weight of the contactor assembly 7 lt is generally lcoated in the bottom section of the cablnet houslng , 2. The positioning of the contactor assembly 7 withln the cablnet hou~lng 2 18 accomplished by insertlng the wheels 49, : whlch are affixed at the four corners of the base 51 of the , ~ :
assembly 7, lnto the guide tracks 53 (Flg. 2) and rolllng the ; assembly 7 into the cabinet housing 2 until electrical engage-,~; ment with electrical terminal assembly 21 occurs. ~`
~- The vacuum-type contactor 7 is designed for starting ~ ~ , and controlling three phase, 50-60 cycle alternating-current ; motors. The voltage may, for example, be 6,600 and the con- ~ `
tactor-closed continuous rating in amperes 360.
Fig. 3 illustrates ln side elevatlon the rlght-; 30 hand side 55 of the truck-mounted vacuum-type contactor ' .: ' :, ' ~; ' 43,102 ~Q366~
assembly 7~ As illustrated in Figo 3, it will be observed that there is provlded a direct-current operating magnet 57 havlng a direct-current magnet coil, or operating coil 59.
Assoclated with the magnet structure 57 is a rotatable magnet armature 61 which makes abutting engagement when the operating magnet 57 is energized with the magnetic pole-face 63. The -lower end 61a of the rotatable magnet armature 61 is affixed by a clamp casting 65 and a key 67 to the external end of an operating shaft 69, as shown. Also afflxed to the operating ;
shaft 69 is an electrical interlock pushrod 71 which operates an electrical interlock 73, the purpose for which wlll be more apparent hereinafter. In addition, Fig. 3 shows a protective resistor 74 which iæ inserteid into the series magnet coil ~; -circuit 57 (Fig. 34) when the armature 61 has reached its ,~
fully-closed position against the pole face 63, as illustrated . :
by the full lines in Fig. 3O Additionally, there is illus-trated in Fig. 3 another interlock 77, the purpose for which will appear more fully herelnafter. Also Fig. 3 lllustrates an isolating-switch m~chanical interlock arm 78, which i9 ..
operable by a downwardly-extendlng interlock rod (not shown) extending downwardly and operable by the isolating-switch assembly 3 (Fig . 11).
, Flg. 3 shows that, general, the truck-mounted contactor assembly 7 comprises two side metallic support plates 80 and 81 interconnected by a front U-shaped metallic support channel member 83, which is more clearly illustrated in Fig. 5 of the drawings. Also Fig. 3 shows the lower stab ~;~ assembly 45 which interconnects the contactor assembly 7 with statlonary load termlnals 21 (Fig. 2) ~or operating an external piece of equipment, such as an electr~cal motor, for . .
- : . - , 43,102 1~3669~4 example.
Flg. 4 illustrates the other, or left-hand side 85 of the vacuum-type contactor assembly 7, which includeæ the other side metallic support plate 80, the two wheels 49 an interlock bar 87 associated with the levering-in mechanism, (not shown) whlch constitutes no part of the present invention.
A1BO Fig. 4 lllustrates the control transformer 33 whlch re-duces the voltage from the llne termlnals Ll, L2 and L3 to a suitable lower voltage level for operatlng the magnet coil 59 of the operating-magnet structure 57. Addltlonally, Fig. 4 shows the interphase barriers 89-92 a flange æupport plate 95 for supportlng the transformer 33 and also a fuse block 97 for the control circuitry 31. ~ -- Fig. 5 illustrates a view looking into the front of the truck-mounted vacuum-type clrcuit-lnterrupter assembly, or contactor assembly 7. It will be observed that the armature 61 of the operating magnet 57 ls affixed to the external end of the operatlng shaft 69 and effects the rotatable operating motlon thereof. The operatlng shaft 69 ; 20 i8, of course, ~ournaled ln sultable bearlngs 99, 101 pro-vided on the lnner side~ 80a, 81a of the two metallic side support plates 80 and 81. Fig. 5 more clearly qhows the fuse block 97, prevlously mentioned ln connectlon wlth Fig. 4, and also the control transformer 33 for the control clrcuitry 31.
It ls, of course, deslrable to provide contact-closlng sprlng pressure for each of the individual pole-unlts 39, 41 and 43 in the closed-circuit positlon of the contactor assembly 7, as illu3trated in Fig. 6 of the drawlngs. Each pole-unit 39, 41 or 43 is provlded with its own lndlvldual ..
vacuum-interrupter unit 103 and a pivotally-mounted rotatable :, ':
. -. ~
~3,102 lQ366~ .
contact operating arm 105, which is pivoted upon a statlonary pivot pin 107 extending between the two downwardly-extendlng flange portions 108, 109 of a U-shaped lower lnterrupter support 110, the conflguration of which is more readily apparent from a study of Figs. 28-30 of the drawings.
The rotatlon of the rotatable contact arm 105 is effected by a laterally-extending cross-bar 112 which is . . . : -moved in generally a vertical direction by two spaced crank-arms 114, 116 the latter being afflxed to and rotatable with , . . .. .
the operating shaft 69. Fig. 5, taken in conJunction with Fig. 6, more clearly shows the structure of the laterally-extending cross-bar 112. A~ illustrated in Fig. 6, it will -- be observed that the cross-bar 112 is preferably of metal, and in thls particular instance has a square cross-section, as shown, havlng end plvot-pins 118, the latter being apparent from a study of Flg. 5 of the drawlngs.
The cross -bar 112 is fixedly secured to an insu- -~
lator support 120 individual to each of the three pole-units 39, 41, and 43 as more clearly illustrated in Flg. 5. The lnsulator support 120, ln turn, supports an abutment member or ln this particlar in~tance a plate 122, for example, having a configuration more clearly apparent from a study of Fig. 10 of the drawings. Fig. 10 illustrates an exploded view of the contact-pressure spring assembly 124 and the relation~hip between the abutment member or plate 122 and a rotatable reverse-current loop-arm assembly 126, again the configuratlon of which ls more clearly apparent from a study of Flg. 10 of the drawings.
As well known by those skllled in the art, it 1 desirable to supply contact spring ~pr eSsSs~urrc on the se bl "-"; ,:
43,102 '' 1~36~4 ~
contacts in the closed-circuit posltion of the interrupter 103. This sprlng pressure, which is provided ln the lnstant lnventlon, ls afforded by a compresslon spring 128 -illustrated in Flgs. 6 and 10, and lnterposed between the abutment plate 122 and an upper movable sprlng seat 130, which straddles the two contact-actuating arms 105a, 105b, r which collectlvely constltute the movable contact-actuating arm 105 of the interrupter assembly 7. -It wlll be observed, in connection wlth Flgs. 6, 7 and 9 of the drawlngs, that a contact drlve pin 132 passes through the two leg portlons 105a, 105b Or the movable contact-actuatlng arm 105 and, addltlonally, passes through - a palr Or apertures 134 provided in the rotatable reverse-current actuatlng arm 136. In other words, the same pivot pln 132 passes through the two leg portlons 105a, 105b of the contact-actuatlng arm 105 and also through the leg portions 136a, 136b constitutlng the reverse-current arm-assembly 136, thereby enabllng a fulcrum polnt to be exerted at the plvot pln 132 in the contact-welded condltlon of the 20 separable contacts 138, 139 under certaln condltlons, as more fully descrlbed herelnafter.
Wlth reference to Flgs. 7, 9 and 10 of the drawlngs, lt wlll be observed that there ls provlded an overtravel - r ad~ustlng nut 140, whlch ls threaded upon the upper end 142a of a contact-pressure stud 142, the lower end of whlch ls secured into the upper end of the lnsulator support 120.
Thus, in the closed-circuit position of the vacuum-interrupter assembly 7, as illustrated in Fig. 7, the contact compression spring 128 is compressed, thereby apply~ng contact-closing 30 pressure between the separable contacts 138 and 139, the :' .
\ 43,102 1~36644 overtravel ad~usting nut 140 accommodating the "wide" travel distance by continued closing travel of the contact-actuating arm 114. Thus, Fig. 7 illustrates the closed-circuit ~-positlon of the lnterrupter device 7 with the operatlng magnet 57 energlzed and the compression spring 128 provlding the desired contact pressure ln the closed-clrcult posltion of the devlce. ~-It wlll be obvious that durlng the openlng opera-tlon, the operating shaft 69 will rotate in a counterclock-wlse direction, as vlewed in Fig. 7, carrying downwardly with - . . .
it the two operating arms 114 and 116 together with the cross-bar 112 and the three insulator supports 120. Also . . ~.: ~
carried downwardly will be the abutment plates 122 and the -contact pressure studs 142 until the overtravel ad~usting nuts 140 engage the yoke portions 130 of the contact actuating - arms 105, as illustrated in Fig. 9 of the drawings.
.
~- Assumlng that there does not exlst a welded condltion at the separable contacts 138, 139, the operating mechanism 144 will ~ ~ .
contlnue its counterclockwlse openlng movement carrylng the 20 separable contacts 138, 139 to thelr fully-open clrcult - position, as lllustrated ln Flg. 9 of the drawlngs.
. ~ . .
The interrupter unit 103 may be of any sultable type manufactured commercially by a number of companles, and, ln general, comprises an evacuated envelope 145 having end metallic plates 146, 147 hermetlcally sealed to the ends of the insulating envelope 145 ~ such as a ceramic sleeve, for example. The vacuum "bottle" 103 ls provlded havlng support-lng stud portions 149, say three in number, for example, . . .
; extending upwardly and downwardly, as illustrated in Flgs. 7 and 9, and also havlng the movable contact stem 150 extending . - . .: . -.
,.- . . :
43,102 ' - ' 366~4 externally, as illustrated ln Flgso 7 and 9. In lts manu-factured component assembly form, lt 1R, therefore, provided ~;
ln a form enabllng lts ready mounting by the six mountlng studs 149 and the movable contact 139 may be opened and closed by an actuatlng clamplng portion 152 secured to the extending end 150a of the movable contact stem 150. The present equip-ment utilizes preferably, one of these manufactured "bottles"
1~3 for each pole-unlt 39, 41, 43. As lllustrated in Flg. 6, there ls provlded an upper interrupter support castlng 154, cast, ln thls partlcular instance, of aluminum, which has a horlzontally-extendlng apertured support-flange portion 154a havlng mounting poles 154b therein to accommodate the three upwardly-extending mounting studs 149, the latter, as mentloned, constltuting a part of the manufactured bottle 103.
Mountlng nuts 156 threadedly secure the support- -flange portlon 154a of the casting 154 to the vacuum "bottle" -103 and maintain it flxedly in a proper position. The . .
casting 154, in addition, has a pair of downwardly-slanting support arms 154c, which are interconnected by a second supporting flange portion, or yoke portion 154d, the latter being affixed to an upper insulator support 158 (Fig. 6) and to a metallic conductor support strap 160, the latter belng securely mounted to an upper fuse-flnger terminal assembly, generally deslgnated by the reference numeral 162, and illustrated more clearly ln Fig. 6 Or the drawings. As . :~ .. , illustrated in Fig. 11, ~he fuse-finger assembly 162 accom-modes a power fuse 164 for each of the individual pole-units 39, 41, 43 of the equlpment 7. A fuse-finger contact-pressure spring 166 is utillzed, as illustrated in Fig. 6, ' 43,102 . ~ ',.
~)36~44 ~:~
.
supported between the pivotal fuse-finger portion 168 of the ~
terminal assembly 162 and a spring seat 170 associated with -a mounting bolt 172, the latter extending through a vertically-disposed insul spacer block 174, the latter being secured by mounting bolts 172, 176 to a laterally-extending insulatlng suport plate 178 of the fram 180. In addition, a metalllc angle 181 is provlded to rigidly lnterconnect the horizontally-extending line-connectlon strap 160 with the horizontally-extending conductor strap 182, Fig. 6 again . . .
showing this construction more clearly. A mounting bolt 184 extends vertically through the several component parts, as also shown in Fig. 6.
Fixedly secured to the upper extremity of a line- -~
connection strap 160 is a terminal clamp 186 havlng a ~
clamping portlon 186a whlch encircles the upper extending end 188 of the stationary contact stem 189, as more clearly :; shown ln Fig. 7. Due to the inherent flexlbllity provlded .... . ..... ..
by the line-connection strap 160 (Fig. 7), there ls not exerted any stress nor torqueing action upon the ~tationary contact stem 188. However, with reference to Fig. 7, it will be observed that the bottle structure 103 itself is rlgldly supported by the relatlvely masslve and heavy upper lnter-rupting casting support 154.
To counteract the lnward closing force exerted because of the evacuated environment 190 wlthln the evacuated enclosure 145, a klckout spring 192 ls provlded to compensate ; for the atmospheric pressure, the latter, of course, tending to force the separable contacts 138, 139 lnto the closed-circuit position, as illustrated in Fig. 7. The kickout ; 30 spring 192 ls interposed between a lower metallic washer 193 :'`. ' -.
- , - - - - - . - . . . . . . . . .: .
` 43,102 ,' ' ~'' ~` ~Q36644 and the upper end of contact operator 152.
With reference to Figs. 6, 7 and 9 of the drawlngs, lt wlll be observed that there is provided at the lower end of the contactor-assembly 7 a reverse-current connector-assembly 126 comprlsing a generally loop-shaped flexible connector 195 having an upper terminal 196 fixedly secured by a connector bolt 197 to the lower end of the movable contact operator 152. The flexible connector 195 extends rightwardly, as viewed in Fig. 7, into a loop portion "L", and then extends toward the left, as viewed in Flg. 7, to be secured by a connector bolt 199 to the mid-portion 200 (Fig. 12) of a stationary U-shaped current-feeding member `4 :.
generally designated by the reference numeral 201 and having a configuration more readily apparent from a study o~ Flgs.
1?-14 of the drawings. ~ -- With reference to Fig. 16 of the drawings, lt wlll ~- be observed that placlng the load-connectlon feed member 203 toward the front of the contactor assembly is commercially ~; inappropriate. Also, as set forth in Flg. 17, providing the constructlon as set forth therein~ with a relatively close spacing "S" between the stationary portlon 205 of the reverse-current loop-connector 207 and the feed-strap member 208 provides an undesirable neutralizatlon effect, as determined by the distance "S" ln Fig. 17.
The more deslrable form is as indicated in Fig. 18 of the drawings, where the current-feed structure 201 comprises a pair of stationary L-shaped leg members 210, 211 bolted, as at ; 212, to the side walls 214, 215 of the lower interrupter -~
casting support 216, and having a bight portlon at the front thereof, deslgnated by the reference numeral 200. The bight "'''., .;
` 43,102 ~036~44 portlon 200 is electrically connected to the lower termlnal 198 of the loop-shaped reverse-current loop assembly 126, as lndicated more clearly ln Fig. 9, whlch has the deslrable advantage, as seb forth in Flgs. 21 and 22 of the drawings, -- namely an augmentation of the upper movable flexible strap -portion 219 by the magnetlc field around the leg portlons 221, 222 of the U-shaped reverse-current feed structure 126.
It wlll be observed that the reverse-current loop force "F" acts to break contact welds when the magnet structure 57 is de-energized, as is the condition set forth in full lines in Fig. 20 of the drawings. Under this particular state of affairs, the force "F" acting is such ' as to create a fulcrum point at the pivot point lOi, thereby ``
tendlng to create a counterclockwise rotative action upon the reverse-current arm 136, thereby bearing agalnst the abutment plate 122, and asslsting the acceleratlng sprlngs ~ s 128 and the operating mechanism 144 in effecting a separation of the contacts 138, 139 within the vacuum-interrupter 103.
By avoiding the utillzatlon of relatlvely-heavy springs, which ln and of themselves would be ¢apable of breaking welds, avoidance of a heavy operating mechanism 144 is advantageoùsly obtained. That is, if relatively heavy ;; ~-~
accelerating springs 128 are utilized, it would take a con- ;
siderably stronger operating mechanism 144 to effect their compression, and thereby bring about the closed-circuit con-dition of the contactor assemblage 7.
In the closed-circuit position of the interrupter, as shown in Flg. 18 9 with the operating magnet 57 energized, the fulcrum polnt ls relocated so as to effect a desirable increase of pressure at the separable contacts 138, 139 ` 43,102 ~.~)3664~
during the attainment of heavy-fault current conditions. At thls time the fulcrum point ls at the movable contact plvot pln, as designated by the rererence numeral 132 ln Flg. 18. --Wlth reference to Flg. 11, the flow of electrical power through the starter 3 can be traced by referrlng to Fig. 11, where the starter 3 is shown in the energized position. The line stab assembly 19, mounted at the back of the cabinet 2 also serves as the starter line terminals Ll, L2 and L3. The stabs themselves are engaged by the fuse ~aws 223 of the lsolation switch 3 which is mounted on rails at the top of the cablnet 2. The llne ferrules 224 of the Type CLS power fuses 164, cllp into the fuse ~aws, and the load ferrules 226 fit into the fuse holders 162 which are part of the contactor line terminals. Power flow through the contactor 7 is from the load ferrules 226 of the power fuses 164, through the interrupter contacts 138, 139 shunt 195 and then to the contactor load terminals 45. The con-tactor 7 is mounted on rails 53 in the lower part of the ;
cabinet 2, immediately ad~acent to the current transformers 27, which are bolted to a panel 9 1n the side of the cabinet2, with the }oad terminals 21 for the starter 1.
Spring-loaded contact ~aws 228 (Fig. 6) mounted on the contactor load terminals 45 plug into a lower stab assembly 21, provlding a convenient connection to the motor load terminals Tl, T2 and T3.
Electrical protection ls provided by the Type CLS
power fuses 164 and by the overload relay 230. The CLS
current limiting power fuses 164 have a speclal time/current characteristic for motor service, and this characteristic is coordinated with the characteristic of the overload relay 230.
~''`'. '~
~~ 43,102 '' . , , . ' 11~36644 Currents greater than full load motor current, up through locked rotor current, will operate the overload relay 230 and trlp the contactor 7 before the fuses 164 blow. This prevents unnecessary blowlng of the fuses 164. Since the lnterruptlng capaclty of the contactor 7 is 50,000 KVA, the power fuses 164 must operate faster than the overload relay 230 when current exceeds thls value, ln order to prevent damage to the contactor 7. In all faults above 50,000 KVA -and wlthin the ratlng of the equipment, the CLS fuses 164 will operate flrst.
The current transformers, overload relay heaters, and power fuses are coordlnated wlth the motor characterlstlcs, so that the starter 1 must be used wlth the motor for whloh ;,, . :. . ' lt was designed. Motors wlth special character~stic or loads requlring special protectlon often require other or additlonal protectlve relays.
j Vacuum contactors are relatlvely new on the market '~ and have en~oyed only llmlted success dur to several short-. .
comlngs.
In an efrort to mlnlmize the most ~erious of the~e shortcomings, the vacuum interrupter manufacturers have found lt necessary to use contact materlals whlch are susceptlble to welding.
; The weldlng problem, however, can be minlmlzed by the use of contact and weld breaking forces approximately ten tlme~ those usually found ln a conventional alr break contactor , :
of comparable rating.
, Vacuum lnterrupters havlng the most deslrable ,.......................................................................... .
lnterruptlng characterlstics and longest contact life have been found to weld at currents considerably below their . . .
43,102 ':
lnterruptlng llmit, so the lnterrupting rating of a contactor uslng these lnterrupters is limited by the ability of the actuating mechanism to overcome the weldlng problem rather than by the arc interrupting ablllty of the lnterrupter.
A three-pole contactor havlng a magnet and frame assembly proportloned to meet the design requlrements of the requirements of the vacuum interrupter and still have a -reasonable mechanical life would be much too large and costly to compete with exlstlng alr-break contactors whlch - 10 requlre only a fraction of the contact force. As a result of this "squeeze," presently avallable vacuum contactors are a deslgn compromise which do not completely satisfy the requlre-ments of the vacuum lnterrupter and as a result do not perform as well as exlstlng alr-break contactors.
The very hlgh contact forces mentloned above are requlred only when lt ls necessary to obtaln the maximum momentary rating of the vacuum lnterrupter whlch is ln the event of a power system fault. Slnce the contactor may seldom see thls condltion ln a¢tual servlce, a contactor designed to -- 20 contlnuously provlde these hlgh forces would represent a rather lnefflclent use of space and materlal.
A reasonable-slzed magnet coupled to the lnter-rupter shaft through a toggle mechanism or other system of levers could be advlsed to develop hlgh contact force, but -the hlgh mechanlcal advantage of this mechanism would act to reduce the contact operating speed far below the values ~ ~ .
recommended for the vacuum lnterrupter. The hlgh mechanlcal advantage of this mechantsm would, ln addition, result in low contact overtravel whlch in turn would make frequent adjustment of contact overtravel necessary. ;~
. ,~ ' .. ' .
43,102 .', '.
. .
lQ36644 Reverse current loops slmilar to the one shown in Flg. 15 have been employed in the past to increase contact force under heavy fault conditions, but have the tendency to override the operating magnet. A reverse current loop 232 (Fig. 15~ of this type, designed to supply the required contact forces of a three-pole vacuum contactor, would exert so much force that the reverse current loop 233 would hold the contacts and magnet closed even after the magnet is de-energlzed. A weak reverse current loop 233 of this type would not hold the contacts closed, but would act to reduce opening speed and weld-breaklng forces, which is also unde-i slrable.
In the disclosed vacuum contactor design 7 (Fig. ;~ ;-20), contact sprlngs, operating magnet and contactor frame details are proportioned to provide contact forces sufficient to insure satisfactory performance under startlng, running, and locked-rotor conditions for the maximum size motor with which the contactor 7 will be used.
These are the operating conditions the contactor 7 wlll see in everyday service, and the mechanical forces which the operating mechanism must be able to endure Por a million or more operatlons.
; Occasionally the contactor 7 may, however, be sub-~ected to power-system fault conditions in which event the contactor 7 may be called on to interrupt or withstand peak currents 10 times or more the maximum peak currents en-- countered in everyday service under locked-rotor or motor-... .
startlng conditions.
In order to handle these higher currents, the vacuum interrupter 103 will require much higher contact and ` ` 43,102 :`
' la36644 weld breaking forces than were necessary for handling the normal motor currents encountered in everyday service. ;
To obtain the higher mechanical ~orces only during an occaslonal system fault, without increasing the mechanical forces in e~ect in normal operation, a novel reverse current loop ls provided as shown in Fig. 20.
This reverse-current loop 126 provides an increase in contact force and also weld-breaklng force which is in proportlon to the square of the current "I" flowing through the reverse current loop.
By properly proportioning the reverse-current loop ~, 126, it is possible to provide a substantial increase in the contact and weld breaking forces under hlgh-current conditions -while only slightly increasing these forces under normal operating conditlons.
The reverse-current loop 126 consists of upper and `~
lower shunt legs 221, 222 plus parallel load connectlon bus bars 210, 211 as shown in Figs. 12 and 20.
When current flows through the reverse current loop conductors 221, 222, the magnetic fields surrounding these conductors 221, 222 react with each other to develop mechanical forces on the varlous conductors.
The lower horizontal leg 222 of the shunt and the ,!
parallel load connection bus bars 210, 211 are restrained by '' non-movable parts of the support structure 180, while the ' ; :,:
,; upper shunt leg 221 is free to move upward until it strlkes ~; -' the right-hand end o~ the reverse-current loop-arm 136.
When the contactor 7 is sub~ected to a power system fault, of high current magnitude, the reverse current loop 30 126 will apply a force upward on the right-hand end of the ~ ;
. ~ .
`` 43,102 ~ i ' , -1~3669~
- reverse-current loop-arm 136 which will in turn pry the inter- -rupter contacts 138, 139 closed as shown ln Flg. 17 assuming the contactor magnet 57 remains closed.
A second reaction of the reverse-current loop-arm 136 is to apply a downward force on the contact spring support plate 122 which wlll in turn increase the openlng veloclty of the magnet and cross-bar assembly 112 once the magnet 57 is de-energized.
When the magnet 57 is released, the moving assembly ls accelerated by the comblned forces of the contact springs 128 and reverse current loop 126 until there is no gap at the ; contact overtravel ad~ustlng nut as shown ln Flg. 20.
At this point, the klnetic energy of the moving system imparts a hammer blow to the contact actuating arm 105 ~ which acts to break any contact welds which might exist.
- When the overtravel ad~usting nut 140 makes con-tact wlth the upper contact spring seat 130, as shown in ^ Figure 20, the function of the reverse current loop 126 automatically takes a complete reversal to apply an additional contact openlng force to the lnterrupter 7 rather than a con-tact closlng, as lt prevlously had done when the magnet 57 was closed.
Use of a flexible shunt 195 doubled back on itself in a conventional manner as shown in Fig. 16 brings the load , connection 203 out the front of the contactor, which is undesirable for use with plug-in devices.
Doubling the load connection back under the lower leg of the shunt 195 as shown in Fig. 17, acts to weaken the magnetic fields and mechanical forces o~ the reverse current loop 207 unless dimension "S" is made relatively large.
''' '~ ' '''' ` 43,102 .
~(~36644 The disclosed design employs a novel arrangement of the current-carrying parts 210, 211 of the reverse current loop 126 which makes it possible to bring the load connections 45 out at the rear of the contactor 7 and at the same time increase rather than decrease the ~orce o~ the reverse current loop as shown in Fig. 22.
In this design the connection ~rom the contactor load terminal 45 to the lower leg 222 of the shunt 195 is dlvided into two parallel legs 210, 211 which straddle and are mounted at the same elevation as the upper leg 221 o~ the shunt.
The magnetlc fields of the two parallel connections 210, 211 to the load terminal 45 combine with the magnetic fields surrounding the shunt 195, as shown in Fig. 22 to shape and to strengthen the resulting magnetic field of the ' reverse current loop 126 in such a manner that the net .;. ,'. ::
s reverse-current loop force "F" ls greater than for the con-.~ ,~ . ..
ventional reverse-current loop shown in Fig. 16. ~`
- A kickout sprlng 192 ls mounted directly on the `
contact shaft 150 of the interrupter 103 to take up the play ~; between the contact actuating mechanism 144 and the interrupter `
contacts 138, 139. Without a kickout spring 192 in this lo-cation, the contacts 138, 139 could touch momentarily under low contact force conditions while play is being taken up in the operating mechanism 144. Play between the contacts and operatlng mechanlsm 144 would aggravate the contact erosion and weldlng problems both on the opening and closlng operations.
The kickout springs 192 also minimize armature bounce on openlng and in addition are proportional to apply ~ ~3~ `
: ' ',;
: ' ' ` 43,102 :
:
1(~;31~;644 :
sufflcient load on the magnet 57 at open gap position to prevent the magnet 57 from picking up unless its operating voltage is sufficlent for the magnet 57 to seal-in from the contact-touch posltion.
Each pole 39, 41 and 43 of the contactor may be installed or removed from the contactor as an individual sub-assembly, so that it may be efficiently assembled or main-tained at a work-beach rather than ln the contactor 7.
. .
; The interrupter unit itself may also be installed or removed from the contactor as a smaller sub-as~embly con-sisting of the interrupter 103, its support 154, moving contact actuating arm 105, and reverse current loop details 126 as shown in the exploded view of Fig. 10.
In order to obtain maximum mechanical life of the interrupter bellows 235 and also avoid friction between the interrupter contact shaft 150 and its bushlng, it is important , that the relatlonship between the contact drlve pin 132 and the plvot pin 107 for the contact actuating arm 105 be ; accurately maintalned.
To accomplish this, the lnterrupter 103 and the ,. . .
.; contact actuating arm 105 are both mounted on a single rlgld .; . .
mechanlcal detail 110 which can be accurately manufactured.
This detail 110 is the lower interrupter mounting bracket shown in Figs. 28-30.
In connection with the above allgnment of parts, it is also desirable that the contacts 138, 139 touch when the contact drive pin 132 ls on the same horizontal center-line 237 as the plvot pin 107 for the contact-actuating arm 105.
When the interrupter sub-assembly is being -31~
`'~' .
. . . ~
~ 43,102 ~lJ3664~
assembled, the kickout spring 192 is placed over the contact shaft 150 and then compressed by the contact operator 152 which ln turn is held in place by the shoulder bolt 239. The - shoulder bolt 239 is only tightened finger tight so as not to apply excessive torque to the interrupter shaft 150 and bellows 235.
The contact operator 152 and shoulder bolt 239 . design is coordinated ln a manner that the shoulder bolt 239 cannot clamp the contact operator 152 to the contact shaft :
150, but instead permits the contact operator 152 to rotate , freely on the contact shaft 150 without applying torque to ~. .
the contact shaft 150 when the contact operator 152 is being ~ .
,. lined up with the contact-actuating arm 105. `
After the contact drive pin 132 is installed, the contact actuating arm 105 is depressed to take up the play ~ ~
; between the contact drlve pin 132 and contact shaft 150 .;
~: .
; following which the contact operator 152 ls clamped to the contact shaft 150 by tightening the clamplng bolt 241. ;:
; In normal servlce, the contact shaft 150 wlll be ;~
actuated through the clamped ~olnt between lt and the contact : .
: .
operator 152, but should this ~oint fail the contacts 138, 139 will then be closed by compression of the parts between the drive pin 132 and the end 150a of the contact shart 150, ~:
and opened by the shoulder bolt 239.
One of the ob~ects of the present invention ls to ,.
prevent excessive torque from being applied to the shaft 150 :~
of the interrupter 103 during malntenance and/or assembly :~
since torque may destroy or shorten the mechanical llfe of .
the interrupter bellows 235. :-The shoulder bolt 239 acts as an assembly fixture : -32- -.' '~ .
` 43,102 ..
~' : ~36644 to compress the kickout spring 192 durlng assembly while still allowing the contact operator 152 to be rotated as ~:~
required to install the contact drive pln 132. In operation the shoulder bolt 239 in addition acts as a safety device :;~
to insure opening of the contacts ln the event the contact - operator 152 ls not securely clamped to the lnterrupter con-tact shaft 150. -~
' The interrupter 103 is rlgidly supported at its . upper end, which contains the interrupter stationary contact `.......... 10 138 so as to avoid transmitting contact forces through the walls 145 of the lnterrupter 103. The moving contact end 150 of the lnterrupter 103 in addition is clamped to the statlonary portion of the pole assembly to provide lateral ::-stability. Clamping of the lower end of the interrupter sub-assembly "SB" is accompllshed by means of an oversized ~ open slot 243 whlch compensates for the manufacturlng '~; tolerances of the interrupter 103 and also simpllfies instal-lation and removal of the interrupter sub-assembly "SB".
Manufacturing tolerances on the interrupter length dimension "X" are rather large, so khe vertlcal locations of the lower ends of the lnterrupter 103 may vary considerably : from contactor 7 to contactor 7 and from pole to pole. Since the operatlng mechanlsm 144 for each pole is mounted on the moving contact end "E" of the indlvidual interrupters 103, rather than on some fixed portion of the pole assembly, thiS : `
is of little consequences. - ~ .
;~ In the event the interrupter length "X" is found to be other than lts nominal value, the final lengths of the con-tact springs 128 will also vary from their nominal value resulting in elther h~gh or low contact forces.
;: -33-~; ;
` 43,102 , , ~036644 The average contact force in the case of a multlple-~` pole contactor~ as shown ln the drawings, can, however, be corrected by adJusting the angular position of the magnet armature 61 on the operatlng shaft 69 so that the correct - average contact spring length and force 128 is obtained when the magnet 57 ls sealed-ln. ` -Angular posltion ad~ustment of the magnet armature 61 is a standard ~eature of an existing air-break contactor magnet 57 applied to the disclosed vacuum contactor 7.
Variatlons in contact ~orces between poles existing after the magnet ad~ustment 61 has been made will fall within allowable limlts lr the contact springs 128 are designed to have a low spring rate.
NON-TORQUE ACTION EXERTED BY SHOULDER-BOLT 239 ~;
To avold lmposing torque action upon the movable contact stem 150 and thereby exerting corresponding torque action upon the bellows 235, the utllization of a novel shoulder-bolt 239 ls provided. The construction of the shoulder-bolt i8 set forth in Figsi 9 and 23 of the drawings.
It wlll be observed that the bore 245 of the contact-shaft operator 152 has a relatively loose fit on the contact stem 150 as shown in Flg. 23, the shank 239a of the shoulder bolt 239 has a loose fit at "Ct' wlth the movable contact operator 152. The shoulder-bolt 239, for example, may have an Allen hèad wlth an enlarged portion 239a and a reduced portion 239b with a shoulder 247 therebetween, so that the shoulder-bolt, ` when tlghtened, will ~orce washers 249 (Fig. 10) against the lower extremity 150a of the movlng-contact shaft 150 of the vacuum-type interrupter 103. Th1s is shown in Fig. 23. The .. . ..
number of washers 249 is arranged to accommodate the .. ~ .;.. :, ; -. . .. .
43,102 , 1~36644 tolerances provided between the different movable contact shafts 150 of the several pole-units 39, 41 and 43. Once the shoulder-bolt 239 is tightened, the contact-shaft operator 152 ls moved manually upwardly, so that there is no clearnace at the polnt"D" in Fig. 23. Then the clamping bolt 241 of Fig.
: 10 is tightened, so that the movable contact shaft 150 is operated by the contact-shaft operator 152, the latter having the apertures 250 provided therein to accommodate the center-line of the contact-drive pin 132. As a result, there is no torque action exerted either upon the movable contact shaft 150, or the bellows 235 located interiorly of the vacuum envelope 103. There may, of course, be relatively wide tolerances provided in the vacuum-bottle manufacture, and the foregoing arrangement permits a desirable accommodation of these tolerances.
~: VACUUM-BOTTLE TOLERANCES
Due to the wlde latitude of the tolerances provided in the manufacture of the vacuum bottles 103, it is desired not to impose any stress upon the ceramic envelope 145, or to effect the breakage of any of the hermetlc seals 251. To effect this end, an accurately-machined lower-interrupter support-plate 110 having the pivot apertures 252 provided .
therein is supplied. These pivot apertures 252 may be accurately machlned, and once the vacuum bottle 103 is fixedly secured by the upper interrupter castlng 154, as a first operation, subsequently, as a separate operation3 the U-shaped accurately-machined support plate 110 is secured into place by the lower three mounting bolts 149. The pivot-pin 132 may then be accurately located with respect to the lower interrupter support 110 because of the accurate machining .
43,102 .
1~:)3~6~4 -:
of the pivot apertures 252 therein.
Thls wlll accurately locate the contact-actuatlng , -lever 105 and, addltlonally, accurately locate the contact- ~:.
stem drlvlng pin 132. As mentioned previously, the contact-shaft clamp bolt 241 i5 tightened as a flnal operation after prevlous assemblage of the contact-pivot pin 132 and tightenlng of the shoulder bolt 239.
WIRING CIRCUIT DIAGRAM FIG. 34 Included ln the wiring clrcuit diagram of Flg. 34 ~;
ls a power-operated main contactor 7 wlth separable power contacts 138, 139 to connect the three-phase load-llnes Tl,~ :
T2, T3 to the power-line conductors 254, 255 and 256, whlch are normally connected to the main supply lines Ll, L2 and L3, through a disconnecting or isolating switch 3 including an arrangement of main power fuses 164 and sets of comple-mentary dlsconnecting contacts 223 (Fig. 11).
Contactor 7 includes an electromagnetic operator .; ::
57 havlng a coil 59, which is energized by a rectifier 259 in responqe to the operation of a normally-biased-open push-button "START" switch 261. Closure of the "START" switch 261 energizes a relay 263 whose normally-open contacts 265 and 267, respectively, connect the output of the rectlfier 259 to the operator 59, and the input of the rectifler 259 to the . .
secondary 269 of a stepdown transformer 44, whose primary 271 ls connected across one phase of the main power-lines Ll, ,: .
L2 and L3. The input to the primary 271 includes fuses 273.
The electromagnetic operator 263 of the contro~ re-lay i8 normally energized from the transformer secondary 269, "-;but may also be energized by a separate source of control power 275 for test purposes.
:~ :
. . - ~ .
, , - . ~ , . .. . ~
` 43,102 .
~: lQ36644 ;:
Included in the output circult of rectifier 259 are the -normally-open contacts 265, male-female type plug disconnects 277, and resistor 279 shunted by a delayed-break auxiliary contact 281 mounted on the magnet assembly 57.
A hold or latch clrcuit 283 is shunted across the "START" button 261 and in¢ludes male-female plug-type discon-nects 285 and normally-open contacts 287, which are operated to close thy circuit 289 across the "START" button 261 when contactor 59 is operated, thereby holding relay 288 and con-sequently contactor 59 ln the operated energized condition.
When contactor 7 closes, delayed-break auxiliary contact 286 openB to insert protectlve resistor 279 in series with the holding coll 59.
The thermostatic switch 290 is an overload switch and responds to the overload current conditions Or the load lines Tl, T2 and T3, as manifested in the heating of resistors ` (not shown) energized respectively from the current trans-formers 27.
From the foregoing description lt will be apparent 20 that there has been provlded an improved operating mechanism for the separable contacts of a circuit-interrupter, parti-cularly applicable to one Or the vacuum-type. Although the instant invention has been described in connection with a vacuum-type circuit-interrupter 10 3, it will be obvlous to those skilled in the art that certain principles, involved in the present disclosure, are pertinent to many other types of lnterrupter units, say those of the air-break type, such as illustrated in Figs. 35-37. In these figures, gas-evolving materials are utillzed instead of an evacuated environment.
,~ 30 However, the desirable conditlons for effecting the breaking . . . - . - . . ~
.
43,102 ~.
~ lQ36644 ;~ ~
o~ welds, or the addition of contact-pressure spring-force in the closed-circuit position of the lnterrupter, when the magnet ls energized, is accomplished in a manner similar to that described heretofore.
Wlth referenct to Figs. 35, 36 and 37 lt wlll be -` observed that there is provided an air-break circult-interrupter 300 havlng a hollow movable contact 301 pivotally connected, as at 132, to the movable contact-actuating arm 105 in a manner ~imilar to that heretofore described in connectlon with Flgs. 6, 7 and 8 of the drawings. The movable contact 301 makes separable contacting engagement wlth a statlonary contact member 303. The movable contact 301 moves downwardly durlngthe openlng operatlon through a generally tubularly-shaped member 305 ~ compo~sed of gas- -evolvlng material, such as flber, Delrln, Celcon/ or llke gas-evolving materlals, as deslred. In addltlon, a follower member 310, more clearly shown in Flg. 36, ls secured by a metalllc rod 312, as at the pivotal pln location 315.
; Durlng the openlng operatlon, as in the manner 20 hereto~ore descrlbed ln connection wlth Fig. 7, the movable tubular contact 301 moves downwardly carrylng wlth lt the plvotally-mounted follower member 310, the latter also belng composed Or gas-evolving materlal. An arc ls establlshed, and the arc ls extlngulshed by the gas evolutlon resulting from the interaction between arc and the surrounding gas-evolving materials. An annular coil 320 may be electrically ; lnterposed between the relatively stationary annularly-shaped contact 303 and a lower-disposed arcing plate 325 to provide a radial magnetic fleld to bring about the rotation of the 30 established arc, and consequently a more intimate engagement ' ' .
` 43,102 ~03~644 thereof with the surrounding gas-evolving material definlng an annular arcing 330 chamber. As will be obvious from an inspection of Fig. 37, the annular arcing member is provlded between the outer surface of the insulating follower member 310, composed of gas-evolving material, and the inner surface of the surrounding insulating cylindrical member 305 also composed of gas-evolving material, as mentioned.
The mechanism 144 may be of the same type as here-tofore described in connection with the vacuum-interrupter 1( 103. Also, in the closed-circuit position of the device, with the contacts 301 and 303 in a welded condition, again the augmentation of the reverse-current loop-arm assisting the operating mechanism 144 is desirable in breaking any welds established at the separable contacts 301 and 303.
; Certain addltional details regarding the inter-rupting structure only of Figs. 35 and 37 are set forth in United States Patent No. 2,294,801, lssued September 1, 1942 to Herbert L. Rawlins, and assigned to the asslgnee of the instant application.
Also, it will be observed that with the lmproved operation mechanism, and the reverse-current loop system, the function of the reverse-current loop-system changes in dependence upon wheteher or not the oepratlng magnet 57 is energized, or is not energized. In the energized state of the operating magnet 57, an addltlonal force ls provlded to malntain the contacts 138, 139 closed durlng the exlstance of heavy-fault-current conditions. When the magnet 57 is not energize~,the fulcrum point changes, or is relocated to there~y provide, instead of a closing force, in this instance an opening force, which assist and augments the accelerating ' ~ ~ ; -,~ :
~ 43,102 16)36644 opening springs. -~ :~
Although there has been illustrated and described ~::
speciflc embodiments of the lnvention, it is to be clearly understood that the ~ame were merely for the purpose of illustration, and that changes and modifications may readily be made therein, by those skilled in the art, without departing from the spirit and scope of the invention.
.
, ~.
., ~
.. .. . ..
, .~ .
'~.'~' ''. '' ' ' , . .
,. ., .:. -': .
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.
Claims (13)
1. A circuit-interrupter including separable contacts at least one of which is movable, a movable operating stem supporting and operating said movable contact, a movable contact-operating arm having a pivotal operating connection with said movable operating stem, means pivotally mounting said movable contact-operating arm at a second stationary pivot-point, means defining a reverse-current movable arm also pivotally mounted on said first pivotal connection, flexible conducting strap-means having one end movable and electrically connected to said movable operating stem, said flexible conducting strap-means additionally having an actuating portion affixed to and movable with one-end of the reverse-current movable arm, the other end of said flexible conducting strap means being maintained in a relatively fixed position to thereby provide a repulsion magnetic force between legs of the reverse current-loop during heavy-fault-current conditions, operating means capable of being energized and de-energized including a contact-compression spring and an abutment member for effecting the rotation of said pivotally-mounted movable contact-operating arm adjacent its free end about the second stationary pivot point, and said reverse-current movable arm bearing upon said abutment member during non-energized conditions of said operating means, whereby weld-breaking forces are magnetically generated about a fulcrum point at said first pivotal con-nection, and whereby in the energized condition of the operating means there is no contact between the abutment member and the reverse-current movable arm and additional contact-closing forces are generated at the reverse-current flexible conducting strap-means.
2. The combination according to claim 1, wherein the operating means includes a support insulator having a threaded stud secured thereto passing through said abutment member, and a contact overtravel adjusting nut is threadedly secured to the end of said stud.
3. me combination according to claim 1, wherein a reverse-current supply circuit includes a generally U-shaped stationary circuit having stationary legs extending on the same general level as the flexible and movable portion of the flexible conducting strap means and the strap means being substantially a flexible conducting looped-shape strap means.
4. me combination according to claim 1, wherein the reverse-current movable arm has a flexible strap re-tainer at its end where the first pivotal connection is located and maintains a fixed connection with said flexible conducting strap-means.
5. me combination according to claim 2, wherein the pivotally-mounted movable contact operating arm comprises two leg portions having a bight portion through which said stud passes, and which bight portion serves as one end of the contact-compression spring means.
6. The combination according to claim 1, wherein the circuit-interrupter is a vacuum-type circuit-interrupting unit.
7. The combination according to claim 6, wherein a kickoff spring encircles the movable contact operating stem and compensates for the surrounding atmospheric pressure tending to force the separable contacts closed within the vacuum interrupter unit.
8. The combination according to claim 4, wherein the reverse-current movable arm comprises a pair of leg portions which are secured together by said flexible strap retainer means.
9. The combination according to claim 1, wherein the second pivotal point is provided by a generally U-shaped stationary support plate member.
10. The combination according to claim 9, wherein the circuit-interrupter unit is a vacuum-interrupter unit, and the U-shaped support plate member has an aperture there-through to accommodate the reciprocal opening and closing movements of the movable contact operating stem.
11. The combination according to claim 1, wherein the operating means includes a laterally-extending cross-bar having two end operating arm-portions which are actuated by an operating magnet.
12. me combination according to claim 11, wherein an operating shaft extends through a side support plate of the circuit interrupter and is actuated externally of the side support plate by the operating magnet.
13. The combination according to claim 3, wherein the reverse-current feed-circuit comprises two substantially L-shaped leg portions dividing the current in parallel and being disposed on the same general level as the flexible movable portion of the loop-shaped flexible conducting strap-means.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US481562A US3921109A (en) | 1974-06-20 | 1974-06-20 | Circuit-interrupter |
Publications (1)
Publication Number | Publication Date |
---|---|
CA1036644A true CA1036644A (en) | 1978-08-15 |
Family
ID=23912445
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA229,201A Expired CA1036644A (en) | 1974-06-20 | 1975-06-12 | Circuit-interrupter |
Country Status (6)
Country | Link |
---|---|
US (1) | US3921109A (en) |
JP (1) | JPS5754884B2 (en) |
AU (1) | AU502337B2 (en) |
CA (1) | CA1036644A (en) |
DE (1) | DE2450424C2 (en) |
GB (1) | GB1505870A (en) |
Families Citing this family (28)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4038626A (en) * | 1975-06-11 | 1977-07-26 | I-T-E Imperial Corporation | High voltage contactor |
US4104496A (en) * | 1977-01-18 | 1978-08-01 | Tokyo Shibaura Electric Co., Ltd. | Vacuum interrupter device |
US4247745A (en) * | 1978-09-13 | 1981-01-27 | Westinghouse Electric Corp. | Vacuum-type contactor assembly |
JPS57109115A (en) * | 1980-12-26 | 1982-07-07 | Sony Corp | Peak shift display device |
DE3111792A1 (en) * | 1981-03-20 | 1982-09-30 | Siemens AG, 1000 Berlin und 8000 München | SWITCH DISCONNECTOR WITH A DRIVE DEVICE FOR JUMPING SWITCHING ON AND OFF |
FR2516297A1 (en) * | 1981-11-09 | 1983-05-13 | Telemecanique Electrique | CONTACTOR APPARATUS COMPRISING AUTOMATIC OPENING MEANS, POWER CIRCUITS, AND A LOCAL CONTROL DEVICE |
FR2516298A1 (en) * | 1981-11-09 | 1983-05-13 | Telemecanique Electrique | CONTACTOR APPARATUS HAVING AUTOMATIC OPENING MEANS AND LOCAL CONTROL MEMBER |
US4513267A (en) * | 1983-03-28 | 1985-04-23 | Siemens-Allis, Inc. | Stationary contact strap to achieve a current limiting blow-off effect |
JPS63132534A (en) * | 1986-11-22 | 1988-06-04 | Anritsu Corp | Measuring instrument for propagation delay time difference between two routes |
US4891841A (en) * | 1988-02-22 | 1990-01-02 | Rane Corporation | Reciprocal, subtractive, audio spectrum equalizer |
DE8905949U1 (en) * | 1989-05-11 | 1990-09-13 | Siemens AG, 1000 Berlin und 8000 München | Multipole vacuum circuit breaker with an insulating support arrangement for the switching tubes |
US5189384A (en) * | 1991-11-06 | 1993-02-23 | Westinghouse Electric Corp. | Circuit breaker having improved contact structure |
US5196815A (en) * | 1992-01-31 | 1993-03-23 | Westinghouse Electric Corp. | Miniature circuit breaker |
DE4210716A1 (en) * | 1992-03-27 | 1993-09-30 | Siemens Ag | Multipole vacuum switch with an insulating arrangement surrounding each vacuum tube |
DE4210714A1 (en) * | 1992-03-27 | 1993-09-30 | Siemens Ag | Vacuum switch with a current loop arrangement |
DE9409006U1 (en) * | 1994-05-30 | 1994-07-28 | Siemens AG, 80333 München | Insulating support for vacuum interrupters |
DE19602118C2 (en) * | 1996-01-22 | 1999-12-30 | Siemens Ag | Electrical switching device |
DE19700758C1 (en) * | 1997-01-11 | 1998-04-02 | Kloeckner Moeller Gmbh | Electrical contact switching device |
US5886860A (en) * | 1997-08-25 | 1999-03-23 | Square D Company | Circuit breakers with PTC (Positive Temperature Coefficient resistivity |
FR2783362B1 (en) * | 1998-09-15 | 2000-12-01 | Soule Materiel Electr | ELECTRICAL NETWORK MANAGEMENT ASSEMBLY INCLUDING IMPROVED CONNECTION MEANS |
US6066814A (en) * | 1999-02-18 | 2000-05-23 | Eaton Corporation | Interlock for switchgear |
ITBG20030018A1 (en) * | 2003-03-07 | 2004-09-08 | Abb Service Srl | LOW VOLTAGE SWITCH AND RELATED DEVICE |
CN101465244B (en) * | 2007-12-17 | 2011-05-04 | 宁波市华安电力电气股份有限公司 | Longitudinal circuit breaker |
CN102737905B (en) * | 2012-06-15 | 2014-11-05 | 新疆新华能电气股份有限公司 | Vacuum circuit breaker self-adaption operating mechanism with properties of permanent magnet and spring mechanism |
US9530579B2 (en) * | 2013-12-26 | 2016-12-27 | Mitsubishi Electric Corporation | Bypass switch |
EP3093862B1 (en) * | 2015-05-11 | 2018-09-12 | General Electric Technology GmbH | Spring arrangement for operating a circuit breaker |
CN109216054A (en) * | 2018-10-24 | 2019-01-15 | 首瑞(天津)电气设备有限公司 | A kind of electric appliance component |
CN113506432B (en) * | 2021-07-07 | 2023-03-28 | 安徽理工大学 | Large-scale server power failure alarm |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1282776B (en) * | 1960-09-08 | 1968-11-14 | Siemens Ag | Electric switch |
GB1053936A (en) * | 1964-08-01 | |||
US3593227A (en) * | 1968-02-28 | 1971-07-13 | Gennady Fedosievich Mitskevich | Automatic electrodynamic blowoff breaker with stationary contact form of two series wound u-shaped members |
FR1580422A (en) * | 1968-07-05 | 1969-09-05 | ||
US3663906A (en) * | 1969-10-09 | 1972-05-16 | Gen Electric | Electric circuit breaker with magnetically assisted closing means |
-
1974
- 1974-06-20 US US481562A patent/US3921109A/en not_active Expired - Lifetime
- 1974-10-23 DE DE2450424A patent/DE2450424C2/en not_active Expired
-
1975
- 1975-06-09 GB GB24607/75A patent/GB1505870A/en not_active Expired
- 1975-06-12 CA CA229,201A patent/CA1036644A/en not_active Expired
- 1975-06-18 AU AU82213/75A patent/AU502337B2/en not_active Expired
- 1975-06-20 JP JP50074604A patent/JPS5754884B2/ja not_active Expired
Also Published As
Publication number | Publication date |
---|---|
AU502337B2 (en) | 1979-07-19 |
DE2450424C2 (en) | 1985-08-22 |
JPS5754884B2 (en) | 1982-11-20 |
GB1505870A (en) | 1978-03-30 |
US3921109A (en) | 1975-11-18 |
JPS5132962A (en) | 1976-03-19 |
DE2450424A1 (en) | 1976-03-18 |
AU8221375A (en) | 1976-12-23 |
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