Patent US3932790A successfully refreshed from Google Patents.
US3932790A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ground fault interrupter with reversed line polarity lamp indicator
Assignee: Hubbell Inc
•
Filing: 1972-02-22
•
Granted: 1976-01-13
•
Expires: 1992-02-22
Abstract
Abstract A ground fault interrupter (GFI) provided with a reversed line polarity lamp indicator to indicate proper installation of the GFI. The reversed line polarity lamp indicator includes a push button and a lamp connected in series between the line conductor of the GFI and ground. In a wiring system having a ground conductor, the series connection is between the line and the ground conductor in which case the reversed line polarity lamp indicator may also be used to check for open circuits in the ground conductor.
Inventors
- 👤 Paul Muchnick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 19:32
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/26; H02H3/32; H02H3/33; H02H3/338; G; G01; G01R; G01R31/00; G01R31/50
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
169 words
A ground fault interrupter comprising: a pair of conductors having input terminals adapted to be connected to an AC power supply having a line and a grounded neutral, and output terminals adapted to be connected to a load; circuit breaker means connected in series with a first of said conductors; current sensing means for sensing differences in current flowing in said conductors and generating a signal responsive thereto; detection and actuation means for receiving said signal and opening said circuit breaker means when said signal indicates a difference current of a predetermined magnitude, and reversed line polarity indicating means associated with said conductors for indicating proper connection of said first of said conductors to said line of said AC power supply, said reversed line polarity indicating means including circuit means for giving an indication of whether or not said first of said conductors is connected to said line of said AC power supply, and actuating means for selectively connecting said circuit means between one of said conductors and ground.
Claim 2
Dependent Claim
169 words
A ground fault interrupter comprising: a pair of conductors having input terminals adapted to be connected to an AC power supply having a line and a grounded neutral, and output terminals adapted to be connected to a load; circuit breaker means connected in series with a first of said conductors; current sensing means for sensing differences in current flowing in said conductors and generating a signal responsive thereto; detection and actuation means for receiving said signal and opening said circuit breaker means when said signal indicates a difference current of a predetermined magnitude, and reversed line polarity indicating means associated with said conductors for indicating proper connection of said first of said conductors to said line of said AC power supply, said reversed line polarity indicating means including circuit means for giving an indication of whether or not said first of said conductors is connected to said line of said AC power supply, and actuating means for selectively connecting said circuit means between one of said conductors and ground.
Claim 3
Dependent Claim
20 words
The ground fault interrupter of claim 1 wherein said circuit means is selectively connected to said first of said conductors.
Claim 4
Dependent Claim
17 words
The ground fault interrupter of claim 1 wherein said actuating means is a manually operable push button.
Claim 5
Dependent Claim
34 words
The ground fault interrupter of claim 1 wherein said circuit means includes a lamp for indicating whether or not said first of said conductors is connected to said line of said AC power supply.
Claim 6
Dependent Claim
22 words
The ground fault interrupter of claim 4 wherein said circuit means further includes a current limiting resistor in series with said lamp.
Claim 7
Dependent Claim
170 words
A ground fault interrupter comprising: a pair of conductors having input terminals adapted to be connected to an AC power supply having a line and a grounded neutral, and output terminals adapted to be connected to a load; circuit breaker means connected in series with a first of said conductors; current sensing means for sensing differences in current flowing in said conductors and generating a signal responsive thereto; detection and actuation means for receiving said signal and opening said circuit breaker means when said signal indicates a difference current of a predetermined magnitude; and reversed line polarity indicating means associated with said conductors for indicating proper connection of said first of said conductors to said line of said AC power supply, said reversed line polarity indicating means including a lamp and selectively operated actuating means for connecting said lamp between one of said conductors and ground, the illumination or nonillumination of said lamp being indicative of which of said conductors is connected to said line of said AC power supply.
Claim 8
Dependent Claim
170 words
A ground fault interrupter comprising: a pair of conductors having input terminals adapted to be connected to an AC power supply having a line and a grounded neutral, and output terminals adapted to be connected to a load; circuit breaker means connected in series with a first of said conductors; current sensing means for sensing differences in current flowing in said conductors and generating a signal responsive thereto; detection and actuation means for receiving said signal and opening said circuit breaker means when said signal indicates a difference current of a predetermined magnitude; and reversed line polarity indicating means associated with said conductors for indicating proper connection of said first of said conductors to said line of said AC power supply, said reversed line polarity indicating means including a lamp and selectively operated actuating means for connecting said lamp between one of said conductors and ground, the illumination or nonillumination of said lamp being indicative of which of said conductors is connected to said line of said AC power supply.
Claim 9
Dependent Claim
46 words
The ground fault interrupter of claim 6 wherein said actuating means selectively connects said lamp to said first of said conductors, thereby rendering illumination of the lamp an indication of proper connection of said first of said conductors to said line of said AC power supply.
Claim 10
Dependent Claim
32 words
The ground fault interrupter of claim 6 wherein said AC power supply further includes a ground conductor and wherein said actuating means selectively connects said lamp to ground through said ground conductor.
References Cited (Backward Citations)
US3313960A
Cited
US3548259A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-01-12 | 1979-07-14 | 1980-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-12 | 1983-07-14 | 1984-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-12 | 1987-07-14 | 1988-01-13 | $7700.00 | Window Closed / Lapsed |