Patent US3604982A successfully refreshed from Google Patents.
US3604982A
Expired / Lapsed
US
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Ground fault and overload current interrupting apparatus
Assignee: Hubbell Inc
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Filing: 1969-02-13
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Granted: 1971-09-14
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Expires: 1989-02-13
Abstract
Abstract A unit which combines the features of electrical overload and ground fault protection. A single circuit breaker includes overload tripping coils and a shunt coil which is energized by the output of a differential transformer. In one form, the unit is designed to operate in a three-wire, grounded neutral system. The shunt coil is operable from both line conductors so that operation from a two-wire supply is possible without modification.
Inventors
- 👤 Thomas M Mcdonald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:30
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/08; H02H3/10; H02H3/105
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
171 words
Ground fault and overload current interrupting apparatus for use with either two or three wire electrical systems without any circuit modification comprising: a differential transformer having at least three primary windings connected in series, respectively, with first and second line conductors and a neutral conductor supplying a load, and a secondary winding; a circuit breaker in series between said primary windings and said load and including overload coils in series with said first and second line conductors and said load, and a shunt coil; a reed switch in series with said shunt coil between both of said first and second line conductors and said neutral conductor; a reed switch actuating coil connected across said secondary winding and a reed switch biasing coil connected between said first and second line conductors and said neutral conductor; and full-wave rectifier means connecting both said reed switch and said biasing coil to both said first and second line conductors for supplying current thereto even if one of said first and second line conductors is deenergized.
Claim 2
Dependent Claim
171 words
Ground fault and overload current interrupting apparatus for use with either two or three wire electrical systems without any circuit modification comprising: a differential transformer having at least three primary windings connected in series, respectively, with first and second line conductors and a neutral conductor supplying a load, and a secondary winding; a circuit breaker in series between said primary windings and said load and including overload coils in series with said first and second line conductors and said load, and a shunt coil; a reed switch in series with said shunt coil between both of said first and second line conductors and said neutral conductor; a reed switch actuating coil connected across said secondary winding and a reed switch biasing coil connected between said first and second line conductors and said neutral conductor; and full-wave rectifier means connecting both said reed switch and said biasing coil to both said first and second line conductors for supplying current thereto even if one of said first and second line conductors is deenergized.
Claim 3
Dependent Claim
39 words
The apparatus of claim 1 wherein said differential transformer, circuit breaker, reed switch, reed switch actuating coil, biasing coil and rectifier means are mounted on a common base for mounting as a single unit on a conventional panel board.
Claim 4
Dependent Claim
12 words
The apparatus of claim 2 including line and load terminals integral therewith.
Claim 5
Dependent Claim
20 words
The apparatus of claIm 2 wherein said circuit breaker defines conventionally positioned mounting holes for connection to said panel board.
Claim 6
Independent Claim
31 words
The apparatus of claim further comprising a potentiometer means connected in series with said biasing coil across said line and neutral conductors for selectively adjusting the sensitivity of said reed switch.
Claim 7
Dependent Claim
22 words
The apparatus of claim 1 wherein a toroidal buffer transformer is connected in series with said differential transformer and said circuit breaker.
Claim 8
Dependent Claim
121 words
Ground fault current interrupting apparatus for use on either a two-wire or a three-wire, grounded neutral, single-phase supply without requiring any circuit modification when changing from one supply to the other which comprises: a differential transformer having a primary winding in series with each of the line and neutral conductors supplying a load and a secondary winding; a circuit breaker in series between said primary windings and said load including a tripping coil; switch means closeable in response to a voltage output from said secondary winding; and means connecting said switch means and tripping coil in series between said neutral conductor and both of said line conductors for supplying current thereto even if one of said said line conductors is deenergized.
Claim 9
Dependent Claim
121 words
Ground fault current interrupting apparatus for use on either a two-wire or a three-wire, grounded neutral, single-phase supply without requiring any circuit modification when changing from one supply to the other which comprises: a differential transformer having a primary winding in series with each of the line and neutral conductors supplying a load and a secondary winding; a circuit breaker in series between said primary windings and said load including a tripping coil; switch means closeable in response to a voltage output from said secondary winding; and means connecting said switch means and tripping coil in series between said neutral conductor and both of said line conductors for supplying current thereto even if one of said said line conductors is deenergized.
Claim 10
Dependent Claim
17 words
The apparatus of claim 7 wherein said connecting means includes a rectifier circuit across said line conductors.
Claim 11
Dependent Claim
30 words
The apparatus of claim 4 wherein said differential transformer is positioned on said base alongside said circuit breaker so as to occupy the space between said base and panel board.
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) | 1974-09-13 | 1975-03-15 | 1975-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-13 | 1979-03-15 | 1979-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-13 | 1983-03-15 | 1983-09-14 | $7700.00 | Window Closed / Lapsed |