US3218400A - Transfer switches for tap-changing regulating transformers having squirrel-cage-shaped support for the fixed contacts thereof - Google Patents

Transfer switches for tap-changing regulating transformers having squirrel-cage-shaped support for the fixed contacts thereof Download PDF

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Publication number
US3218400A
US3218400A US289517A US28951763A US3218400A US 3218400 A US3218400 A US 3218400A US 289517 A US289517 A US 289517A US 28951763 A US28951763 A US 28951763A US 3218400 A US3218400 A US 3218400A
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Prior art keywords
pairs
contacts
contact
fixed contacts
fixed
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US289517A
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English (en)
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Bleibtreu Alexander
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Maschinenfabrik Reinhausen Gebrueder Scheubeck GmbH and Co KG
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Maschinenfabrik Reinhausen Gebrueder Scheubeck GmbH and Co KG
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    • 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
    • H01H9/0005—Tap change devices
    • 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
    • H01H9/0005—Tap change devices
    • H01H9/0044—Casings; Mountings; Disposition in transformer housing

Definitions

  • Another object of this invention is to provide transfer switches which can be more readily maintained than comparable prior art transfer switches.
  • Another object of this invention is to provide transfer switches having longer creepage path and a higher dielectric strength than comparable prior art transfer switches.
  • Another object of this invention is to provide improved transfer switches for so-called Janson type tap-changing regulating transformers.
  • Another object of this invention is to provide an improved version of the transfer switch disclosed and claimed in the copending patent application of Alexander Bleibtreu, filed Jan. 31, 1963, Ser. No. 255,291 for Transfer Switch for Tap Changers for Regulating Transformers.
  • Tap-changing regulating transformers include selector switches and transfer switches.
  • the selector switches serve the purpose of selecting a particular tap on a tapped transformer winding intended to be connected into an electric circuit.
  • Selector switches are not required to interrupt current carrying circuits, or to close on current carrying circuits.
  • This tas k is performed by the transfer switches. The latter perform all switching operations under load. Therefore all arcing is kept away from the selector switches and occurs only at the transfer switches. It is, therefore, of considerable importance that the transfer switches be designed to effectively cope with power arcs resulting from load switching operations and overload switching operations.
  • FIG. 1 shows a prior art transfer switch know as pennant transfer switch
  • FIG. 2 is mainly a vertical section through a transfer switch for a three phase circuit embodying the present invention, some parts thereof being shown in front elevation rather than in vertical section;
  • FIG. 3 is a horizontal section through the structure of FIG. 2 showing the fixed main contacts and the fixed auxiliary contacts of three phases thereof in top-plan view and showing movable main contacts and the movable auxiliary contacts of but one of the three phases;
  • FIG. 4 is an isometric view of a portion of the structure of FIGS. 2 and 3.
  • FIG. 1 shows a portion Tr of a tapped transformer Winding.
  • the transfer switch comprises four movable contacts 1, 2, 3, 4.
  • a cylindrical contact support 6a of insulating material supports four fixed contacts adapted to be cooperatively engaged by the aforementioned movable contacts 1, 2, 3, 4.
  • the taps U U of the tapped portion of winding Tr are directly connected by appropriate leads to the outer or fixed main contacts of the transfer switch.
  • the taps U U are further connected by the intermediary of ohmic resistors R to the inner or fixed auxiliary contacts of the transfer switch.
  • the movable contacts 1 and 3, on the one hand, and the movable contacts 2 and 4, on the other hand, form part of separate or different contact operating systems.
  • tap U is directly connected to a point indicated by a small arrow.
  • Changing the connection of that point from tap U to tap U involves a closing operation of movable auxiliary contact 3 preceding the separation of the left movable main contact 1 from its cooperating fixed main contact.
  • the fixed auxiliary contact cooperating with the movable auxiliary contact 3 is connected to tap U by the intermediary of right resistor R, the closing operation of contact 3 gives rise to a circulating current. This circulating current is superimposed upon the load current.
  • each movable contact of the structure of FIG. 1 may be adapted to selectively engage such a pair of fixed contacts and to part from such a pair of fixed contacts.
  • the embodiment of the invention shown in FIGS. 2-4 is a transfer switch adapted in the aforementioned fashion to form serially related double breaks at each point of break.
  • the three phase transfer switch shown in FIGS. 2-4 comprises a cylindrical tank 1 accommodating the coaxial supporting structure 2.
  • Structure 2 comprises a bottom frame member 3, a top frame member 4 and a plurality of vertically insulating rods or bars 5. The latter are angularly displaced and spaced and supported by frame members 3, 4. Thus parts 3, 4, 5 form a squirrel cage structure.
  • Tank 1 may contain a body of dil (not shown).
  • Terminal 1a is integral with tank 1 which may be made of an appropriate insulating material. This terminal is intended to connect the transfer switch to the neutral point of the regulating transformer.
  • Other terminals (not shown) provide a connection between the transfer switch and the selector switch of the transformer. The latter terminals may be arranged in pairs in view of the high current-carrying duty imposed upon these parts. If tank 1 is made of a casting resin the terminals of the transfer switch may be in the form of inserts in the casting as shown in the upper left corner of FIG. 1.
  • Top frame member 4 is made of metal and provided with contacts cooperatively engaging with terminal 1a.
  • a structure substantially in the shape of a second radially inner squirrel-cage is suspended on frame member 4 by means of screws 11.
  • the upper end plate 15 and the lower end plate 16 are fixedly mounted upon operating shaft 17 resting in bearings 17a, 17b.
  • Shaft 17 is arranged in coaxial relation to tank 1 and squirrel cage structures 2 and 12, 13, 14, respectively.
  • Rods 18 of which but one is shown in the drawings are spaced from shaft 17 and extend parallel to shaft 17.
  • the upper ends and the lower ends of rods 18 are loosely guided by the upper end plate 15 and the lower end plate 16, respectively.
  • the upper ends of rods 18 are mechanically tied to the upper end plate 15 by means of helical tension springs 19 of which but one is shown in the drawings.
  • the lower ends of rods 18 are mechanically tied to the lower end plate 16 by means of helical tension springs 19 of which but one has been shown in the drawings.
  • Reference numeral 20 has been applied to indicate a plurality of upper contact operating arms and reference numeral 21 has been applied to indicate a plurality of lower contact operating arms.
  • Each contact operating arm 20, 21 has a radially inner bearing 18a and a radially outer bearing 22a.
  • Rods 18 extend through the radially inner bearings 18a of contact operating arms 20, 21.
  • the bearings 22a on the radially outer ends of each pair of contact operating arms 20, 21 support a vertical shaft 22 which, in turn, supports a contact carrier 23.
  • Contact carriers 23 insulatingly support contact bridges 24 extending parallel to operating shaft 17.
  • Reference numeral 24a has been applied in FIG. 2 to indicate the insulating layer separating each contact carrier 23 from the contact bridge 24 being carried by it.
  • the aforementioned upper and lower plate members 12, 13 are provided with radially extending slots or grooves 12' and 13, respectively, engaged by and guiding the upper and the lower ends of contact carriers 23. Because of this function of plate members 12, 13 the same may be referred to as guide plates.
  • each contact bridge 24 and the lower end of each contact bridge 24 are adapted to cooperate with a pair of fixed contacts 6, 6.
  • Each pair of fixed contacts 6 is supported by one of the aforementioned vertical bars forming part of squirrel cage structure 2.
  • Bars 5 are made of an appropriate insulating material and are preferably H-shaped in cross-section.
  • each bar 5 defines a radially inner channel-shaped space and a radially outer channel-shaped space.
  • Contacts 6 are accommodated in the radially inner channel-shaped spaces defined by bars 5.
  • Contacts 6 are maintained in position on bars 5 by means of screws or equivalent defined by rods or bars 5. Therefore the heads 25 of the screws are located in the radially outer channel spaces defined by rods ro bars 5. Therefore the heads 25 of the screws supporting fixed contacts 6 are readily accessible from the outside of radially outer cage structure 2.
  • FIG. 1 calls for the provision of four contact carriers 23 and of four contact bridges 24 and of four pairs of fixed contacts 6, 6 per phase.
  • the number of contact carriers, contact bridges and of pairs of fixed contacts per phase may be smaller than four or larger than four.
  • FIGS. 2-4 comprises six pairs of fixed contacts 6, 6 and six movable contact bridges 24 per phase.
  • the contacts 6, 6, 24 of each phase are arranged in form of a sector of a circle.
  • the fixed contacts 6, 6 at the ends of each such sector are main arcing contacts and the fixed contacts of each such sector arranged between main contacts are auxiliary arcing contacts to be connected to switching resistors such as the resistors R shown in FIG. 1.
  • FIG. 3 shows all the arcing contacts pertaining to one phase, omitting the movable arcing contacts or contact bridges 24 of the two other phases.
  • FIGS. 2-4 The current path of the structure of FIGS. 2-4 is substantially the same as explained in connection with FIG. 1.
  • the current path extends through lower arcing contacts 6, contact bridges 24 and upper arcing contacts 6.
  • Upper contacts 6 are conductively connected to element 4 which is, in turn, connected to the neutral point of the three phase system. (The conductor means conductively connecting the upper contacts 6 to element 4 and thus establishing a Y connection have been omitted in FIG. 2.)
  • FIGS. 2 to 4 The kinematic theory underlying the structure of FIGS. 2 to 4 is set forth in detail in United States Patent 2,680,- 790 to Bernhard Jansen, June 8, 1954 for Load Changeover Switch for Tapped Transformers Using a Combination of Contact Movements (see particularly FIG. 5 and column 6, line 55 to column 7, line 23) and reference may be had to that patent for additional information regarding this subject.
  • the operation of the structure of FIGS. 2-4 is briefly as follows: Pivotal movement of shaft 17 under the bias of the spring of a switch operating mechanism (not shown) results in rotary motions of parts 15, 16 transmitted to shafts 18.
  • transfer switches embodying the present invention dispense entirely with flexible connections, or braids, for energizing the movable contact segments including contact bridges 24.
  • contact bridges 24 are insulated from their supports 23, all the movable parts within the transfer switch may be made of metal rather than of insulating material, which greatly contributes to the ruggedness of transfer switches embodying the present invention.
  • the ruggedness of such transfer switches is due in particular to the presence of the squirrel-cage type structure comprising guide plates 12, 13 and the three conductive squirrel-cage bars 14.
  • FIGS. 2-4 greatly increases the life of the cooperating contacts 6, 24, 6, it is of great importance to readily obtain access to all parts of the switch which are subjected to wear and tear.
  • the inspection and/or replacement of the radially outer fixed contacts was a relatively difiicult task, requiring a radially inward retraction of the contact bridges and their supporting structures. Performance of this task calls for special tools and highly skilled labor.
  • the structure of FIGS. 2-4 greatly facilitates inspection and/ or replacement of fixed contacts 6, 6. All that is required to this end is removal of the contact supporting bars 5 from cage structure 2. This can be readily achieved since the heads 25 of the bar-supporting screws are arranged on the radially outer surfaces of bars 5.
  • the gaps which are present between contiguous bars 5 make it possible to inspect the transfer switch in a general way upon removal thereof from its oil-filled tank 1 without disassembly of any parts thereof. Since the contacts 6, 6 and their supporting rods or bars 5 are surrounded by oil or other equivalent insulating liquid on all the sides thereof, creepage paths otherwise always present in the fixed contact supporting structure of transfer switches are substantially eliminated, resulting in a considerable increase of the dielectric strength of the structure. Another factor tending to increase the dielectric strength of the structure is the arrangement of contacts 6, 6 within recesses or channels formed by rods 5. Replacement of a pair of defective fixed contacts can readily be achieved by removing its contact supporting rod and replacing the same by a like rod having contacts in perfect operating condition.
  • the entire transfer switch structure inside of insulating housing 1 may be lifted bodily out of the latter for the purpose of inspection, maintenance and repair.
  • the transfer switch When the transfer switch has been lifted out of tank 1 its fixed contacts 6 and its contact bridges 24 are substantially exposed to view through the gaps formed between contiguous contact supports 5. This greatly facilitates inspection of the fixed contacts and the contact bridges.
  • Replacement of any pair of fixed contacts which may show evidence of excessive wear or erosion may be readily effected by substituting a new contact support 5 with a pair of new fixed contacts 6 thereon for the contact support with the contacts showing evidence of excessive wear or erosion.
  • a body of oil, or other insulating fiuid, filled into tank 1 envelops each of the contact supporting bars 5 from all sides thereof, i.e.
  • a transfer switch for tap-changing regulating transformers comprising in combination:
  • each of said plurality of spaced members defines on the radially inner side thereof a channel space accommodating one of said plurality of superimposed registering pairs of fixed contacts.
  • each of said plurality of members is substantially H-shaped in crossseetion, each defining a radially outer channel-shaped space and a radially inner channel-shaped space separated by a web, each radially inner channel-shaped space of said plurality of members accommodating one of said plurality of pairs of fixed contacts, and wherein fastener means securing one of said plurality of pairs of fixed contacts to each of said plurality of members are arranged in each radially outer channel-shaped space of each of said plurality of members.
  • a transfer switch for tap-changing regulating transformers as specified in claim 1 comprising a body of insulating liquid in said tank filling the spaces between contiguous members and Wholly surrounding each of said members of said plurality of members.
  • a transfer switch for tap-changing regulating transformers comprising in combination:
  • an insulating support for said plurality of pairs of fixed contacts formed by a structure substantially in the shape of a squirrel-cage and including a bottom frame member, a top frame member and a plurality of angularly spaced supporting bars for said plurality of fixed contacts extending between said bottom frame member and said top frame member and supported by said bottom frame member and by said top frame member, said plurality of supporting bars being spaced radially from said cylindrical surface of said tank and each of said plurality of supporting bars defining jointly with said cylindrical surface of said tank a gap of predetermined width, and each of said plurality of supporting bars supporting on the radially inner side thereof one of said plurality of pairs of fixed contacts.
  • a transfer switch for tap-changing regulating transformers comprising in combination:
  • a plurality of contact bridges each adapted to cooperate with one of said plurality of pairs of fixed contacts, said plurality of contact bridges including two main contact bridges each adapted to cooperate with one of said two pairs of fixed main contacts, and said plurality of contact bridges further including auxiliary contact bridges each adapted to cooperate with one of said pairs of auxiliary fixed contacts;
  • a transfer switch for tap-changers for regulating transformers comprising in combination:
  • each pair of said plurality of pairs of fixed contacts being arranged along a line parallel to said switch housing, and each of said plurality of pairs of fixed contacts being angularly spaced from a contiguous pair of said plurality of pairs of fixed contacts;
  • pivotable operating means including linkage means for causing radial movement of said plurality of contact carriers relative to said pair of guide plates to effect a predetermined sequential engagement of each of said plurality of pairs of fixed contacts by one of said plurality of contact bridges, and
  • a transfer switch for tap-changers for regulating transformers comprising in combination:
  • each pair of said plurality of pairs of fixed contacts being aligned along a line parallel to said switch housing and each of said plurality of pairs of fixed contacts being angularly spaced from a contiguous pair of said plurality of pairs of fixed contacts;
  • each of said plurality of pairs of contact operating arms having radially inner bearings mounted on said rod means and having radially outer bearings;
  • each of said plurality of rods supporting one of said plurality of pairs of fixed contacts and each of said plurality of rods defining a channel on the radially inner side thereof wherein one of said plurality of pairs of fixed contacts is recessed.
  • a transfer switch for tap-changing regulating transformers comprising in combination:
  • each of said plurality of pairs of fixed arcing contacts being arranged along one of a plurality of angularly displaced generatrices of a cylindrical surface parallel to and spaced from said housing, said plurality of pairs of fixed arcing contacts including two outer pairs of fixed main arcing contacts and inner pairs of fixed auxiliary arcing contacts arranged between said two pairs of main arcing contacts;
  • a plurality of parallel contact bridges arranged inside said housing, extending in a direction longitudinally thereof and each being adapted to engage with, and part from, one of said plurality of pairs of fixed arcing contacts, said plurality of contacts bridges including two main contact bridges each adapted to engage with, and to part from, one of said two pairs of fixed main arcing contacts, and said plurality of contact bridges further including auxiliary contact bridges each adapted to engage with, and to part from, one of said pairs of fixed auxiliary arcing contacts;
  • operating means for said plurality of contact bridges to cause in a predetermined sequence engagement of each of said plurality of contact bridges with, and parting of each said plurality of contact bridges from, one of said plurality of pairs of spaced fixed arcing contacts, said operating means including a driving shaft arranged in said housing in coaxial relation thereto, a pair of spaced end plates fixedly mounted on and jointly pivotable with said shaft and a plurality of linkage means for transmitting the pivotal motion of said pair of end plates to said plurality of contact bridges; and
  • each of said plurality of bars being substantially H-shaped in cross-section and defining a radially inner channel and a radially outer channel, each of said plurality of bars supporting one of said plurality of pairs of fixed arcing contacts recessed in said radially inner channel thereof.
  • a transfer switch for tap-changing regulating transformers comprising in combination:
  • operating means for said plurality of contact bridges to cause engagement of each of said plurality of contact bridges with, and parting of each of said plurality of contact bridges from, one of said plurality of pairs of fixed arcing contacts in a predetermined sequence
  • said operating means including a driving shaft arranged in said housing in coaxial relation thereto, a pair of axially spaced end plates having a larger axial spacing than the axial spacing of said pair of guide plates and fixedly mounted on and jointly pivotable With said shaft and a plurality of linkage means for transmitting the pivotal motion of said pair of end plates to said plurality of contact bridges;
  • a transfer switch for tap-changing regulating transformers comprising in combination:
  • operating means for said plurality of contact bridges and for said plurality of contact bridge supports to cause engagement of each of said plurality of contact bridges with, and parting of each of said plurality of contact bridges from, one of said plurality of pairs of fixed arcing contacts in a predetermined sequence
  • said operating means including a driving shaft arranged in said switch housing in coaxial relation thereto, a pair of axially spaced end plates having a larger axial spacing than the axial spacing of said pair of guide plates and fixedly mounted on and jointly pivotable with said shaft and a plurality of linkage means for transmitting the pivotal motion of said pair of end plates to said plurality of contact bridge supports;

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Housings And Mounting Of Transformers (AREA)
  • Arc-Extinguishing Devices That Are Switches (AREA)
US289517A 1962-07-21 1963-06-21 Transfer switches for tap-changing regulating transformers having squirrel-cage-shaped support for the fixed contacts thereof Expired - Lifetime US3218400A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DEM0053648 1962-07-21
DEM57996A DE1276190B (de) 1962-07-21 1963-08-28 Lastumschalter fuer Stufenschalter von Regeltransformatoren

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US3218400A true US3218400A (en) 1965-11-16

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US289517A Expired - Lifetime US3218400A (en) 1962-07-21 1963-06-21 Transfer switches for tap-changing regulating transformers having squirrel-cage-shaped support for the fixed contacts thereof

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US (1) US3218400A (fr)
AT (1) AT242814B (fr)
BE (2) BE652431A (fr)
CH (2) CH403074A (fr)
DE (1) DE1276190B (fr)
GB (2) GB991445A (fr)
NL (4) NL6404936A (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116525324A (zh) * 2023-06-14 2023-08-01 双城市国开电气制造有限公司 一种35kv干式真空有载分接开关

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2747489C3 (de) * 1977-10-22 1982-01-21 Maschinenfabrik Reinhausen Gebrüder Scheubeck GmbH & Co KG, 8400 Regensburg Lastumschalter für Stufenschalter von Stufentransformatoren
DE2913271C2 (de) * 1979-04-03 1982-11-18 Maschinenfabrik Reinhausen Gebrüder Scheubeck GmbH & Co KG, 8400 Regensburg Dreiphasiger Lastwähler für Stufentransformatoren
DE3322173A1 (de) * 1983-06-21 1985-01-03 Maschinenfabrik Reinhausen Gebrüder Scheubeck GmbH & Co KG, 8400 Regensburg Zylindrisches oelgefaess fuer stufenschalter von stufentransformatoren

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2680790A (en) * 1951-03-07 1954-06-08 Jansen Bernhard Load changeover switch for tapped transformers using a combination of contact movements
US2833873A (en) * 1956-01-07 1958-05-06 Jansen Bernhard Multi-pole tap switch construction for changing transformer taps under load

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT196974B (de) * 1956-01-07 1958-04-10 Bernhard Dr Ing Jansen Lastumschalter für Stufentransformatoren

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2680790A (en) * 1951-03-07 1954-06-08 Jansen Bernhard Load changeover switch for tapped transformers using a combination of contact movements
US2833873A (en) * 1956-01-07 1958-05-06 Jansen Bernhard Multi-pole tap switch construction for changing transformer taps under load

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116525324A (zh) * 2023-06-14 2023-08-01 双城市国开电气制造有限公司 一种35kv干式真空有载分接开关
CN116525324B (zh) * 2023-06-14 2023-10-20 双城市国开电气制造有限公司 一种35kv干式真空有载分接开关

Also Published As

Publication number Publication date
NL125149C (fr)
NL6404936A (fr) 1965-06-25
CH403074A (de) 1965-11-30
DE1276190B (de) 1968-08-29
CH492293A (de) 1970-06-15
AT242814B (de) 1965-10-11
NL121761C (fr)
BE652431A (fr) 1964-12-16
GB1031879A (en) 1966-06-02
NL294975A (fr)
GB991445A (en) 1965-05-05
BE635180A (fr)

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