US3569641A - Metal-clad isolator switches comprising earthing devices - Google Patents
Metal-clad isolator switches comprising earthing devices Download PDFInfo
- Publication number
- US3569641A US3569641A US867745A US3569641DA US3569641A US 3569641 A US3569641 A US 3569641A US 867745 A US867745 A US 867745A US 3569641D A US3569641D A US 3569641DA US 3569641 A US3569641 A US 3569641A
- Authority
- US
- United States
- Prior art keywords
- contact
- switching
- earthing
- holder
- breaking
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000002184 metal Substances 0.000 claims description 29
- 238000005192 partition Methods 0.000 claims description 11
- 239000011810 insulating material Substances 0.000 claims description 10
- 239000012212 insulator Substances 0.000 claims description 9
- 230000007246 mechanism Effects 0.000 claims description 9
- 230000008878 coupling Effects 0.000 claims description 4
- 238000010168 coupling process Methods 0.000 claims description 4
- 238000005859 coupling reaction Methods 0.000 claims description 4
- 230000004044 response Effects 0.000 claims description 2
- 230000008901 benefit Effects 0.000 description 3
- 101100074836 Caenorhabditis elegans lin-22 gene Proteins 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000005294 ferromagnetic effect Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H3/00—Mechanisms for operating contacts
- H01H3/32—Driving mechanisms, i.e. for transmitting driving force to the contacts
- H01H3/40—Driving mechanisms, i.e. for transmitting driving force to the contacts using friction, toothed, or screw-and-nut gearing
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H31/00—Air-break switches for high tension without arc-extinguishing or arc-preventing means
- H01H31/14—Air-break switches for high tension without arc-extinguishing or arc-preventing means with bridging contact that is not electrically connected to either line contact in open position of switch
- H01H31/24—Air-break switches for high tension without arc-extinguishing or arc-preventing means with bridging contact that is not electrically connected to either line contact in open position of switch with rectilinearly-movable bridging contact
-
- 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
- H01H33/46—Interlocking mechanisms
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
- H01H9/16—Indicators for switching condition, e.g. "on" or "off"
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02B—BOARDS, SUBSTATIONS OR SWITCHING ARRANGEMENTS FOR THE SUPPLY OR DISTRIBUTION OF ELECTRIC POWER
- H02B13/00—Arrangement of switchgear in which switches are enclosed in, or structurally associated with, a casing, e.g. cubicle
- H02B13/02—Arrangement of switchgear in which switches are enclosed in, or structurally associated with, a casing, e.g. cubicle with metal casing
- H02B13/035—Gas-insulated switchgear
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02B—BOARDS, SUBSTATIONS OR SWITCHING ARRANGEMENTS FOR THE SUPPLY OR DISTRIBUTION OF ELECTRIC POWER
- H02B13/00—Arrangement of switchgear in which switches are enclosed in, or structurally associated with, a casing, e.g. cubicle
- H02B13/02—Arrangement of switchgear in which switches are enclosed in, or structurally associated with, a casing, e.g. cubicle with metal casing
- H02B13/035—Gas-insulated switchgear
- H02B13/075—Earthing arrangements
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H3/00—Mechanisms for operating contacts
- H01H3/32—Driving mechanisms, i.e. for transmitting driving force to the contacts
- H01H3/40—Driving mechanisms, i.e. for transmitting driving force to the contacts using friction, toothed, or screw-and-nut gearing
- H01H2003/405—Driving mechanisms, i.e. for transmitting driving force to the contacts using friction, toothed, or screw-and-nut gearing using a walking nut
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
- H01H9/02—Bases, casings, or covers
- H01H2009/0292—Transparent window or opening, e.g. for allowing visual inspection of contact position or contact condition
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H31/00—Air-break switches for high tension without arc-extinguishing or arc-preventing means
- H01H31/003—Earthing switches
Definitions
- METALCLAD HSOLATOR SWTTCHES COMPRISTNG lE G DEVICES BACKGROUND AND SUMMARY OF THE INVENTION to the envelope, which insulator divides the space inside the envelope into two switching chambers which are separated from one another ina gastight manner, each containing a fixed contact and a switching rod.
- a device for earthing the holder and the switching rods when the isolator switch is in its opened condition is provided within the envelope.
- the switching rods and the earthing switching contact or contacts must be coupled in such a manner that the earthingswitching contact is brought into its closed position. Prior to the time that the switching rods reach said safe distance, the earthing switching contact is locked in its openjposition. Moreover, there must be such a coupling between'ithe isolator switch and the earthing switch such that the earthing switch is in its closed position with certainty when the isolator switch is in its open position.
- the switching rods and the earthing switching contact must be so interconnected throughtheir driving mechanisms or through individual locking means as to earthing device consists of at least one fixed contact attached to the envelope and at least one switching contact cooperating with the fixed contact and pivotally connected to the holder, said switching contact being adapted to be swung about a transverse axis and being directly mechanically driven by one of the switching rods and said switching contact being directly mechanically locked either in its contact-breaking position or in its contact-making end position by said switching rod, when the latter is in its respective contact-rnaking or in its contactbreaking end position.
- the isolator switch constructed in accordance with the invention has, in comparison with the mentioned rotary switches, the advantage that the insulating distances within the envelope can be kept small and the provision of a satisfactory seal between the separated switching chambers is possible, which is particularly important with regard to the requirement that one must be able to open either one of the two switching chambers for inspection and repair purposes, while the other switching chamber remains electrically alive and under overpressure.
- the isolator switch constructed in accordance with the invention has the advantage of a reliable coupling and interlocking of the various movable contacts due to the direct mechanical coupling thereof.
- a simple construction is obtained according to the invention by using a switching contact of the earthing device which forms one arm of a two-arm lever and is provided with a cam,
- lever being in the form of a tail for driving the earthing switching contact and locking sarneainreither one of its end positions.
- Said cam and said tail cooperate directly with pressure surfaces of one of the isolator switching rods such that just before the switching rod has reached, during its contact-breaking movement, its contact-breaking end position, a first pressure surface of the switching rod engages said cam, whereby the earthing switching contact is swung a little in the contact-making direction and brought with its tail within the reach of a second pressure surface of the switching rod.
- the switching contact is forced by said second pressure surface into and is locked in the contact-making end position, and just after said switching rod has left, dur ing its contact-making movement, its contact-breaking end position a third pressure surface of the switching rod engages the tail of the earthing switching contact, whereby said earthing switching contact is swung back into the contactbreaking end position and, during the further contact-making movement of the switching rod, said earthing switching contact is locked in its contact-breaking end position by said rod. Consequently, in this way the switching rods and the earthing switching contact are coupled without any connecting member, which is of considerable benefit to the reliability and the safety in operation.
- the isolator switch may be advantageously constructed'in such a manner that the holder is a metal tube which surrounds the switching rods entirely or almost entirely when theyare in their contact-breaking end position, said holder being provided with at least one longitudinal slot to receive an earthing switching contact when such contact is in its contacbbreaking end position, and two rotatable threaded spindles are provided which extend in the axis of said tube and are coupled both with each other-and with a transversely directed driving shaft of insulating material by driving means accommodated in said tube, each spindle extending in a central cavity of a switching rod and cooperating with a nut attached to said switching rod and locked against rotation.
- the tubular holder then operates at the same time as a screen for the electrical potential distribution when the isolator switch is in its closed condition and the earthing switching contact is in its opened condition. This allows of the radial insulating distance to be decreased, notwithstanding the fact that one or more eccentrically disposed earthing switching contacts are attached to the holder.
- a simple driving mechanism to which also a position indicator may be positively coupled, is obtained by constructing the driving meansto consist of two conical toothed wheels, each of which is secured to a threaded spindle, and of a third conical toothed wheel meshing with said two conical toothed wheels and secured tothe driving shaft constructed of insulating material, and in which at least a fourth conical toothed wheel forms part of the driving means, said fourth conical wheel also meshing with the two conical toothed wheels of the threaded spindles and being coupled with a position indicator by a shaft of insulating material which is transversely directed to the tubular holder.
- the position indicator is coupled with the inner driving means independently of the driving shaft for the transmission of the driving torque, whereby the danger of a faulty indication of the state of the isolator switch is reduced.
- a device provided on the earthed metal envelope and intended to indicate the contact-making end position of said switching contact.
- This device may, for instance, be a marked end face of the earthing switching contact which appears behind a window of the envelope, when said switching contact is in its contact-making end position.
- the isolator switch provided with the tubular holder canbe readily divided into two parts which are separated from each other in a gastight manner.
- the tubular holder is provided with atleast one partition, through which a cylindrical end portion forming part of a threaded spindleand facing the driving means extends in a gastight mannenTheprovision of a rotatable shaft extending through a wall does not offer great difficulty in sealing even at great differences between the pressures on both sides of said wall. Since only one threaded spindle has to extend through the partition provided in the tubular holder, one switching rod may be provided entirely on one side and the other switching rod may be provided entirely on the other side of said partition. Both switching rods are then pneumatically relieved of stresses, irrespective of whether the gas pressure on both sides of said partition are equal or unequal, so that the driving mechanism need not operate against a pressure difference.
- FIGURE is an axial sectional view of an isolator switch comprising an earthing device constructed in accordance with the invention.
- the reference numerals 1, 2 and 2' designate parts of a tubular metal envelope intended to be connected to earth and within which a disc-shaped insulator 3 is mounted to separate the chambers on spaces 23 and 24 from each other.
- a tubular metal holder 4 which extends through the insulator 3 in a gastight manner.
- the holder 4 is provided with two axially movable hollow switching rods 5 and 6, which mount respective nuts 7 and 8 receiving the respective threaded spindles 9 and 10 which extend in the axis of the holder 4 and the switching rods 5 and 6.
- the nuts 7 and 8 and the switching rods 5 and 6 are secured against rotation by respective pins 12 and 13 engaging longitudinal grooves 11 (only one shown) of the holder 4.
- the switching rods 5 and 6 are adapted to be axially moved in and out of the tubular holder 4 by means of the threaded spindles 9 and 10 and the switching rods 5 and 6 cooperate with respective fixed contacts 14 and 15 which may be permanently electrically conductively connected with elements (not shown) of a switching installation.
- the switching rods 5 and 6 which move in opposite directions, and the fixed contacts 14 and 15 constitute together an isolator switch for double interruption of high voltage systems.
- the tubular holder 4 contains driving means which consist of two conical toothed wheels 16 and 17 which are secured on the facing end portions of the threaded spindles 9 and 10 and which are coupled by a third conical toothed wheel 18 adapted to be driven from the outside of the metal envelope by means of a driving shaft 19 of insulating material which is directed transversely to the holder 4.
- the conical toothed wheels 16 and 17 are coupled to each other by a fourth conical toothed wheel 20 which is coupled by means of a shaft 21 of insulating material to a position indicator 22 disposed outside the envelope.
- the spindle 10 is provided with a cylindrical end portion 25 which extends in a gastight manner through a partition 26 arranged within the tubular holder 4 and provided with a seal 27.
- the switching rod 5 cooperates with two earthing switching contacts which are each formed as a two-arm lever pivotally connected to the holder 4. These levers are adapted to be swung about transverse pivots 28 and 29 with the respective long arms 30 and 31 constituting the earthing switching contacts and the short arms 32 and 33 formed as tails intended for driving and locking said switching contacts.
- Each earthing switching contact 30 and 31 cooperates with a fixed contact 34 or 35 attached to the portion 1 of the metal envelope and connected by a bolt 36 or 37 and a nut 38 or 39 to a cable 40 or 41 connected to earth.
- the isolator switch In the condition shown in full lines the isolator switch is in its contact-making end position and the earthing switching contacts 30 and 31 lie respectively in the longitudinal slots 42 and 43 of the holder 4.
- the tails 32 and 33 of the earthing switching contacts then rest against the cylindrical outer surface of the switching rod 5, so that the earthing switching contacts 30 and 31 are locked in their contact-breaking end positrons.
- Each earthing switching contact 30 and 31 is provided, near its free end, with a cam 44 or 45 and the switching rod 5 has three pressure surfaces for each earthing switching contact of which the first one 46 is the rear end face of the switching rod whereas the second one 47 or 47a and the third one 48 or 48a are formed by walls of holes 49, 50 provided in the switching rod 5.
- the switching rods 5 and 6 are moved towards each other and drawn into the tubular holder 4. Just before they reach their contact-breaking end position, the tails 32 and 33 of the earthing switching contacts 30 and 31 come to register with the holes 49 and 50, whereby said contacts are unlocked from their contact-breaking end positions. Continued movement of the switching rods causes the surface 46 to engage the cams 44 and 45 so that the earthing switching contacts 30 and 31 are swung slightly in the contact-making direction.
- the tails 32 and 33 are swung into the holes 49 and 50 so that they may be engaged by the second pressure surfaces 47 and 47a whereby they are swung, during the further contact-breaking movement of the switching rod 5, in the direction corresponding to the contact-making direction of the earthing switching contacts 30 and 31, ultimately to force said contacts into their contactmaking end positions in which their free end portions engage the fixed earthing contacts 34 and 35 (see the position in dotted lines).
- the earthing switching contacts 30 and 31 are locked positively by the tails 32 and 33.
- the third pressure surfaces 48 and 48a force the tails 32, 33 out of the holes 49 and 50 just after the switching rod 5 has left its contact-breaking end position so that the earthing switching contacts 30 and 31 are then swung back to their contact-breaking end positions in which they lie in the longitudinal slots 42 and 43.
- the tails 32 and 33 slide over the cylindrical outer surface of the switching rod 5 so that the earthing switching contacts 30 and 31 are locked in their contact-breaking end positions.
- each earthing switching contact 30 and 31 is provided with a ferromagnetic armature plate 51 or 52 which is kept in place by one of the magnets 53 or 54 mounted in the holder 4 when said earthing switching contacts are in their contact-breaking end position.
- Each earthing switching contact 30 and 31 is provided on its free end face with a plate 55 or 56 having a visible sign which appears, in the contact-making end position of the switching contact, behind a window 57 or 58 formed in the wall of the envelope portion 1 so that a direct indication of the earthed condition of the holder 4 and the switched-off switching rods 5 and 6 is obtained.
- a metal clad isolator switch for high voltage and double interruption comprising a metal envelope intended to be connected with earth, two axially spaced fixed contacts and two switching rods movable in axially opposite directions between contact-making and contact-breaking end positions, both said fixed contacts and said switching rods being accommodated in and insulated from said envelope, one of said switching rods cooperating with one fixed contact and the other switching rod cooperating with the other fixed contact, an electrically conductive holder permanently electrically conductively interconnecting said switching rods, and insulator peripherally attached to the envelope between said fixed contacts and supporting said holder, means including said holder and said insulator dividing the space inside the envelope into two switching chambers which are separated from one another in a gastight manner and each of which contains one of said fixed contacts and at least a portion of a cooperating switching rod, driving means with a portion thereof provided in said holder for axially shifting said switching rods in relatively opposite directions, means for earthing the holder and the switching rods when the isolator switch is
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Driving Mechanisms And Operating Circuits Of Arc-Extinguishing High-Tension Switches (AREA)
- Arc-Extinguishing Devices That Are Switches (AREA)
- Mechanisms For Operating Contacts (AREA)
- Switch Cases, Indication, And Locking (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL696900061A NL146974B (nl) | 1969-01-03 | 1969-01-03 | Geheel gesloten scheidingsschakelaar voor hoge spanning, met dubbele onderbreking en met een door de schakelstift bediend, als zwaaibaar schakelmes uitgevoerd aardingscontact. |
Publications (1)
Publication Number | Publication Date |
---|---|
US3569641A true US3569641A (en) | 1971-03-09 |
Family
ID=19805788
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US867745A Expired - Lifetime US3569641A (en) | 1969-01-03 | 1969-10-20 | Metal-clad isolator switches comprising earthing devices |
Country Status (9)
Country | Link |
---|---|
US (1) | US3569641A (enrdf_load_stackoverflow) |
JP (1) | JPS5025626B1 (enrdf_load_stackoverflow) |
AT (1) | AT295635B (enrdf_load_stackoverflow) |
BE (1) | BE743514A (enrdf_load_stackoverflow) |
DE (2) | DE6911092U (enrdf_load_stackoverflow) |
FR (1) | FR2027697A1 (enrdf_load_stackoverflow) |
GB (1) | GB1254790A (enrdf_load_stackoverflow) |
NL (1) | NL146974B (enrdf_load_stackoverflow) |
SE (1) | SE365911B (enrdf_load_stackoverflow) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2001057896A1 (en) * | 2000-02-03 | 2001-08-09 | Abb Ab | Circuit breaker |
US20070158311A1 (en) * | 2003-08-07 | 2007-07-12 | Areva T&D Sa | Three-position ground switch |
CN101436485B (zh) * | 2008-12-22 | 2010-12-01 | 南京双京电器有限责任公司 | 小型高压旋转隔离开关 |
US8723069B2 (en) | 2009-06-23 | 2014-05-13 | Siemens Aktiengesellschaft | Viewing window and ground contact connection for a high-voltage arrangement |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CH654442A5 (de) * | 1981-05-22 | 1986-02-14 | Sprecher & Schuh Ag | Vorrichtung zum gegenseitigen verriegeln der antriebe zweier elektrischer trennschalter. |
EP0684673B1 (de) * | 1994-04-18 | 1998-05-13 | ABBPATENT GmbH | Schaltfeld mit einem innerhalb eines Schaltschrankes angeordneten dreipoligen Leistungsschalters |
CN113593938B (zh) * | 2021-07-27 | 2024-11-22 | 平高集团有限公司 | 一种静触头组件及隔离开关 |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1872298A (en) * | 1927-11-23 | 1932-08-16 | Westinghouse Electric & Mfg Co | Switch mechanism |
US3277252A (en) * | 1962-12-17 | 1966-10-04 | English Electric Co Ltd | Electric switchgear having integral earthing contacts |
-
1969
- 1969-01-03 NL NL696900061A patent/NL146974B/xx not_active IP Right Cessation
- 1969-03-19 DE DE6911092U patent/DE6911092U/de not_active Expired
- 1969-03-19 DE DE19691913981 patent/DE1913981B2/de active Pending
- 1969-04-08 FR FR6910725A patent/FR2027697A1/fr not_active Withdrawn
- 1969-07-29 AT AT731369A patent/AT295635B/de not_active IP Right Cessation
- 1969-10-20 US US867745A patent/US3569641A/en not_active Expired - Lifetime
- 1969-11-17 SE SE15777/69A patent/SE365911B/xx unknown
- 1969-12-04 JP JP44096837A patent/JPS5025626B1/ja active Pending
- 1969-12-22 BE BE743514D patent/BE743514A/xx not_active IP Right Cessation
- 1969-12-23 GB GB62641/69A patent/GB1254790A/en not_active Expired
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1872298A (en) * | 1927-11-23 | 1932-08-16 | Westinghouse Electric & Mfg Co | Switch mechanism |
US3277252A (en) * | 1962-12-17 | 1966-10-04 | English Electric Co Ltd | Electric switchgear having integral earthing contacts |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2001057896A1 (en) * | 2000-02-03 | 2001-08-09 | Abb Ab | Circuit breaker |
US20070158311A1 (en) * | 2003-08-07 | 2007-07-12 | Areva T&D Sa | Three-position ground switch |
US7429710B2 (en) * | 2003-08-07 | 2008-09-30 | Areva T&D Sa | Three-position ground switch |
CN101436485B (zh) * | 2008-12-22 | 2010-12-01 | 南京双京电器有限责任公司 | 小型高压旋转隔离开关 |
US8723069B2 (en) | 2009-06-23 | 2014-05-13 | Siemens Aktiengesellschaft | Viewing window and ground contact connection for a high-voltage arrangement |
Also Published As
Publication number | Publication date |
---|---|
JPS5025626B1 (enrdf_load_stackoverflow) | 1975-08-25 |
FR2027697A1 (enrdf_load_stackoverflow) | 1970-10-02 |
DE6911092U (de) | 1969-10-23 |
BE743514A (enrdf_load_stackoverflow) | 1970-05-28 |
DE1913981B2 (de) | 1971-06-09 |
AT295635B (de) | 1972-01-10 |
DE1913981A1 (de) | 1970-11-12 |
GB1254790A (en) | 1971-11-24 |
NL6900061A (enrdf_load_stackoverflow) | 1970-07-07 |
NL146974B (nl) | 1975-08-15 |
SE365911B (enrdf_load_stackoverflow) | 1974-04-01 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US3665135A (en) | Metal clad isolator switches for high tension and double interruption | |
US4268890A (en) | Breaker combination for bus bar installations | |
US3569641A (en) | Metal-clad isolator switches comprising earthing devices | |
KR930008893A (ko) | 축으로 블로우아웃(blowout)된 코일을 갖는 하이브리드 차단기 | |
RU2340977C2 (ru) | Коммутационный аппарат с функцией размыкания и/или заземления | |
US4486634A (en) | Ground test switch for gas insulated switchgear | |
US4184058A (en) | Polyphase isolator switches | |
JP4521110B2 (ja) | 複合型ガス絶縁開閉装置 | |
US3562460A (en) | Double contact disconnect switch structure with contacts in gastight sealed relationship with a tubular support | |
GB966110A (en) | Circuit interrupter | |
US2506991A (en) | Circuit breaker | |
US3889076A (en) | Combination of a pressurized-gas insulated high-voltage switching installation and a multi-pole grounding switch device | |
US3206580A (en) | Fluid immersed tap changing switching system for transformers | |
US3646284A (en) | High-voltage circuit breakers | |
GB1433264A (en) | Vacuum circuit interrupotrs | |
US3397293A (en) | Metal-clad switchgear employing vacuum type circuit interrupters | |
CA1141410A (en) | Three-phase unitary vacuum switch | |
US3485971A (en) | Fully enclosed switching devices for high voltages | |
US4315119A (en) | Tank type gas circuit breaker | |
DE2138456A1 (de) | Metallgekapselte hochspannungsschaltanlage | |
JPH05501195A (ja) | 三極金属容器密閉形圧縮ガス絶縁高電圧開閉設備 | |
GB1424412A (en) | Switch and mechanism therefor | |
US4440998A (en) | Segmented circuit breaker housing with rotatably adjustable bushing positions | |
US3700840A (en) | Isolating switch | |
US3655930A (en) | Multiple vacuum switch apparatus having longitudinal actuator |