Patent US3894274A successfully refreshed from Google Patents.
US3894274A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric motor transient voltage suppressing circuit
Assignee: General Electric Co
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Filing: 1974-07-01
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Granted: 1975-07-08
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Expires: 1994-07-01
Abstract
Abstract An electric power distribution system or an electric device, such as a motor, having a relatively low voltage class of insulation on the conductors or windings thereof is provided with a transient voltage suppressing circuit that is operable to prevent undesirable voltage peaks from being applied to the insulation. Due to the voltage distributing and stabilizing effect of the suppressing circuit, the heat dissipating characteristics of motor windings, combined with the circuit, may be improved and the long-term insulation life of the motor is thereby made more reliable.
Inventors
- 👤 Jr George Mowry Rosenberry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:15
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/08; H02H7/09; H02H9/00; H02H9/04
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
131 words
An electric distribUtion system having a plurality of electrical conductors equal in number to N that are to be protected from transient voltages, in combination with a transient voltage suppressing circuit comprising a plurality of metal oxide varistors equal in number to N plus 1, all but one of said varistors being connected in a star configuration with one of the respective terminals of each star-connected varistor being electrically connected in common, electric conductor means connecting each conductor, respectively, of the N conductors of the distribution system to an associated outer varistor terminal of the star configuration of varistors, the remaining varistor being electrically connected in series between the common connection of the star configuration of varistors and an electrical ground terminal, each of said varistors having substantially identical electrical characteristics.
Claim 2
Dependent Claim
131 words
An electric distribUtion system having a plurality of electrical conductors equal in number to N that are to be protected from transient voltages, in combination with a transient voltage suppressing circuit comprising a plurality of metal oxide varistors equal in number to N plus 1, all but one of said varistors being connected in a star configuration with one of the respective terminals of each star-connected varistor being electrically connected in common, electric conductor means connecting each conductor, respectively, of the N conductors of the distribution system to an associated outer varistor terminal of the star configuration of varistors, the remaining varistor being electrically connected in series between the common connection of the star configuration of varistors and an electrical ground terminal, each of said varistors having substantially identical electrical characteristics.
Claim 3
Dependent Claim
11 words
An invention as defined in claim 1 wherein N equals 2.
Claim 4
Dependent Claim
109 words
An electric motor having a polyphase winding provided with a transient voltage suppressing circuit that enables the use of a relatively low voltage class of insulation on the windings, said voltage suppressing circuit comprising a plurality of metal oxide varistors electrically connected in a star configuration with one terminal of each varistor electrically connected in common, electric conductor means connecting each phase winding of the motor, respectively, to an associated outer terminal of the star configuration of varistors, and a common varistor electrically connected in series between the common connection of the star configuration and an electrical ground terminal, each of said varistors having substantially identical electrical operating characteristics.
Claim 5
Dependent Claim
109 words
An electric motor having a polyphase winding provided with a transient voltage suppressing circuit that enables the use of a relatively low voltage class of insulation on the windings, said voltage suppressing circuit comprising a plurality of metal oxide varistors electrically connected in a star configuration with one terminal of each varistor electrically connected in common, electric conductor means connecting each phase winding of the motor, respectively, to an associated outer terminal of the star configuration of varistors, and a common varistor electrically connected in series between the common connection of the star configuration and an electrical ground terminal, each of said varistors having substantially identical electrical operating characteristics.
Claim 6
Dependent Claim
25 words
An invention as defined in claim 3 wherein each of the varistors electrically connected in said star configuration comprises a single phase, dual terminal varistor.
Claim 7
Dependent Claim
45 words
An invention as defined in claim 3 wherein said polyphase winding is a wye-connected three-phase winding and the star configuration of varistors is also a wye connection having each of its outer terminals connected, respectively, to an outer terminal of the wye connected motor winding.
Claim 8
Dependent Claim
64 words
An invention as defined in claim 3 wherein said polyphase winding is a three-phase winding having two terminals on each winding that are selectively connectable to enable the motor winding to be connected with either a wye or delta winding, said electric conductor means being effective to connect each of said winding terminals to an associated outer terminal of the star configuration of varistors.
Claim 9
Dependent Claim
23 words
An invention as defined in claim 2 including a single-phase motor connected in operating relationship to the two conductors of said distribution system.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-07 | 1979-01-06 | 1979-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-07 | 1983-01-06 | 1983-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-07 | 1987-01-06 | 1987-07-08 | $7700.00 | Window Closed / Lapsed |