US3898557A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical device for testing a ground fault circuit interrupter
Assignee: Daltec Systems Inc
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Filing: 1974-04-15
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Granted: 1975-08-05
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Expires: 1994-04-15
Abstract
Abstract An electrical circuit for extensive testing of a ground fault interrupter. Means to create a current differential between the hot and neutral conductors of a ground fault interrupter device, and thereby test the circuit interrupt features of said device, are disclosed. Means are also provided for determining the sensitivity of the device being tested to an accidental grounding of the neutral conductor. The invention also can be used to check the wiring connections between the ground fault interrupter and the electrical system to which it is attached. A further advantage of the invention is that it provides an indirect test of said electrical system. Modifications to the circuitry will provide similar testing devices for two and three phase ground fault interrupters.
Inventors
- 👤 Joseph P Strock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 01:46
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/26; H02H3/32; H02H3/33; H02H3/334; H02H3/335
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
152 words
An electrical device for testing a ground fault interrupter comprising: a plug with a plurality of prongs designated as ground, neutral and charged, said prongs being dimensioned to be received in correspondingly designated receptacles of a ground fault interrupter or a circuit protected by a ground fault interrupter; circuit means in the device connected across each prong designated as charged and the ground prong to determine if the charged prong is received by a charged receptacle; circuit means connected across each charged prong and the ground prong to create a current differential between the prongs received by the charged and neutral receptacles, said current differential means including a switch connected in series with an impedance element capable of drawing a current equal to the trip current of the apparatus being tested; and circuit means connected across the neutral and ground prongs to short circuit the neutral prong to a low impedance ground.
Claim 2
Dependent Claim
152 words
An electrical device for testing a ground fault interrupter comprising: a plug with a plurality of prongs designated as ground, neutral and charged, said prongs being dimensioned to be received in correspondingly designated receptacles of a ground fault interrupter or a circuit protected by a ground fault interrupter; circuit means in the device connected across each prong designated as charged and the ground prong to determine if the charged prong is received by a charged receptacle; circuit means connected across each charged prong and the ground prong to create a current differential between the prongs received by the charged and neutral receptacles, said current differential means including a switch connected in series with an impedance element capable of drawing a current equal to the trip current of the apparatus being tested; and circuit means connected across the neutral and ground prongs to short circuit the neutral prong to a low impedance ground.
Claim 3
Dependent Claim
31 words
The device of claim 1 wherein said means to determine whether a prong designated as charged is received by a charged receptacle includes a lamp and a resistor connected in series.
Claim 4
Dependent Claim
17 words
The device of claim 1 wherein said impedance element is of the type whose impedance is variable.
Claim 5
Dependent Claim
20 words
The device of claim 1 wherein said short circuit means includes a switch connected in series with an impedance element.
Claim 6
Dependent Claim
99 words
The device of claim 1 wherein said short circuit means includes: a first switch and a first impedance element connected in series across the prong received by the neutral receptacle and a reference point; a second impedance element across the reference point and the prong received by the ground receptacle; and at least one series of elements including a second switch and a third impedance element connected across the prong received by the charged receptacle and the reference point, said third impedance element being capable of drawing a current equal to the trip current of the apparatus being tested.
Claim 7
Dependent Claim
65 words
The device of claim 1 wherein the short circuit means includes: a first impedance element across the prong received by the charged receptacle and a reference point; a second impedance element across the prong received by the neutral receptacle and the reference point; and a third impedance element in series with a switch across the reference point and the prong received by the ground receptacle.
References Cited (Backward Citations)
US2131386A
Cited
US2382647A
Cited
US2623107A
Cited
US3176219A
Cited
US3263164A
Cited
US3205436A
Cited
US3376502A
Cited
US3668518A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-08-04 | 1979-02-03 | 1979-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-04 | 1983-02-03 | 1983-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-04 | 1987-02-03 | 1987-08-05 | $7700.00 | Window Closed / Lapsed |