Patent US3911323A successfully refreshed from Google Patents.
US3911323A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ground fault protector with arcing fault indicator
Assignee: Westinghouse Electric Corp
•
Filing: 1974-02-19
•
Granted: 1975-10-07
•
Expires: 1994-02-19
Abstract
Abstract A ground fault detector having an indicator which indicates the presence of a ground or similar fault in an electrical line to be protected where the fault current is not of sufficient magnitude to cause the ground fault indicator to trip a circuit breaker to thereby interrupt the circuit in which the ground fault current is flowing. The indicating circuit provides a recognizable warning that a ground fault has begun or is in progress so that appropriate steps may be taken to cure the fault to locate the fault, or to indicate the relative magnitude of the fault current before it worsens.
Inventors
- 👤 John T Wilson
- 👤 James C Wilson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:20
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/02; H02H3/04; H02H3/16; H02H3/162
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
100 words
A fault indicator for a ground fault detector comprising, sensing means for sensing ground fault current in an electrical circuit and providing an output signal related to said ground fault current without causing interruption of said circuit, nonmagnetic indicating means including an input terminal connected to said sensing means for receiving said output signal therefrom, said indicating means proViding an indication of the presence of said ground fault current in said electrical circuit before said ground fault current is of a predetermined value sufficient to cause said sensing means to cause said circuit to be interrupted by separate interrupting means.
Claim 2
Dependent Claim
100 words
A fault indicator for a ground fault detector comprising, sensing means for sensing ground fault current in an electrical circuit and providing an output signal related to said ground fault current without causing interruption of said circuit, nonmagnetic indicating means including an input terminal connected to said sensing means for receiving said output signal therefrom, said indicating means proViding an indication of the presence of said ground fault current in said electrical circuit before said ground fault current is of a predetermined value sufficient to cause said sensing means to cause said circuit to be interrupted by separate interrupting means.
Claim 3
Dependent Claim
80 words
A multi-level ground fault detector comprising, sensing means for sensing current in an electrical circuit and providing an output signal related to the level of said current, non-magnetic indicating means including an input terminal connected to said sensing means for receiving said output signal and providing an indication of the presence of a first predetermined level of said current, circuit interrupting means for interrupting at least a portion of said current after said current has reached a second predetermined level.
Claim 4
Dependent Claim
80 words
A multi-level ground fault detector comprising, sensing means for sensing current in an electrical circuit and providing an output signal related to the level of said current, non-magnetic indicating means including an input terminal connected to said sensing means for receiving said output signal and providing an indication of the presence of a first predetermined level of said current, circuit interrupting means for interrupting at least a portion of said current after said current has reached a second predetermined level.
Claim 5
Dependent Claim
23 words
The combination as claimed in claim 1 wherein said indicating means provides an indication of the relative magnitude of said ground fault circuit.
Claim 6
Dependent Claim
23 words
The combination as claimed in claim 2 wherein said indicating means provides an indication of the relative magnitude of said ground fault current.
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) | 1978-10-06 | 1979-04-07 | 1979-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-06 | 1983-04-07 | 1983-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-06 | 1987-04-07 | 1987-10-07 | $7700.00 | Window Closed / Lapsed |