US3586911A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical distribution system
Assignee: SWEET DONALD
•
Filing: 1968-07-01
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Granted: 1971-06-22
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Expires: 1988-07-01
Abstract
Abstract An electrical distribution system is described wherein a grounded source supplies power to an ungrounded load through an isolation transformer with an ungrounded secondary. To prevent unnecessary loading by the isolation transformer primary during no-load conditions, the electrical source is connected to the isolation transformer primary only in the presence of a load. The circuit includes a ground sensing network which operates to disable the power source in the event the secondary circuit becomes grounded thereby creating a potentially hazardous condition. To prevent temporary ground conditions from permanently disabling the system, the circuit acts to automatically reset for a predetermined number of cycles after a ground condition is sensed. If the ground condition remains after the plurality of recyclings, then the system must be reset by hand after the grounded condition is remedied.
Inventors
- 👤 Arthur A Kraus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:12
CPC Classifications
H; H02; H02H; H02H3/00; H02H3/16; H02H3/162; H02H3/02; H02H3/06; H02H3/07; H02H3/12
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
170 words
In an ungrounded electrical power supply system, the combination comprising: 1. circuit means for detecting the flow of current to ground in said system, 2. switching means, having opened and closed positions, in said system for disabling said system when the switching means is in its open position and for enabling said system when switching means is in its closed position, and 3. means coupled to said detecting means and responsive to the detection of current flow to ground, for controlling said switching means by placing said switching means in its open position for a predetermined period of time when a flow of current to ground is detected, and for placing said switching means in its closed position after the expiration of said predetermined period of time, whereby said switching means cycles between its opened and closed positions while the ground condition exists, said control means further including means for maintaining said switching means in its open position after it has opened and closed for a predetermined number of cycles.
Claim 2
Dependent Claim
170 words
In an ungrounded electrical power supply system, the combination comprising: 1. circuit means for detecting the flow of current to ground in said system, 2. switching means, having opened and closed positions, in said system for disabling said system when the switching means is in its open position and for enabling said system when switching means is in its closed position, and 3. means coupled to said detecting means and responsive to the detection of current flow to ground, for controlling said switching means by placing said switching means in its open position for a predetermined period of time when a flow of current to ground is detected, and for placing said switching means in its closed position after the expiration of said predetermined period of time, whereby said switching means cycles between its opened and closed positions while the ground condition exists, said control means further including means for maintaining said switching means in its open position after it has opened and closed for a predetermined number of cycles.
Claim 3
Dependent Claim
37 words
switching means, having opened and closed positions, in said system for disabling said system when the switching means is in its open position and for enabling said system when switching means is in its closed position, and
Claim 4
Dependent Claim
37 words
switching means, having opened and closed positions, in said system for disabling said system when the switching means is in its open position and for enabling said system when switching means is in its closed position, and
Claim 5
Dependent Claim
34 words
The combination of claim 1 wherein said switching means includes first switching means which periodically closes and opens and second switching means which opens if ground condition remains for a predetermined period of time.
Claim 6
Dependent Claim
8 words
an isolation transformer and an ungrounded load circuit,
Claim 7
Dependent Claim
8 words
an isolation transformer and an ungrounded load circuit,
Claim 8
Dependent Claim
107 words
means coupled to said detecting means and responsive to the detection of current flow to ground, for controlling said switching means by placing said switching means in its open position for a predetermined period of time when a flow of current to ground is detected, and for placing said switching means in its closed position after the expiration of said predetermined period of time, whereby said switching means cycles between its opened and closed positions while the ground condition exists, said control means further including means for maintaining said switching means in its open position after it has opened and closed for a predetermined number of cycles.
Claim 9
Dependent Claim
107 words
means coupled to said detecting means and responsive to the detection of current flow to ground, for controlling said switching means by placing said switching means in its open position for a predetermined period of time when a flow of current to ground is detected, and for placing said switching means in its closed position after the expiration of said predetermined period of time, whereby said switching means cycles between its opened and closed positions while the ground condition exists, said control means further including means for maintaining said switching means in its open position after it has opened and closed for a predetermined number of cycles.
Claim 10
Dependent Claim
26 words
means for causing power transfer from said source to the primary of said transformer only when the load of said load circuit exceeds a predetermined value,
Claim 11
Dependent Claim
26 words
means for causing power transfer from said source to the primary of said transformer only when the load of said load circuit exceeds a predetermined value,
Claim 12
Dependent Claim
44 words
The combination of claim 2 wherein the rate of operation of said first switching means is such that it opens approximately 5 seconds after it closes and said second switching means opens after said first switching means has opened and closed approximately five times.
Claim 13
Dependent Claim
17 words
The combination of claim 1 further including indicator means for indicating the presence of a ground condition.
Claim 14
Dependent Claim
14 words
circuit means for detecting the flow of current to ground in said load circuit,
Claim 15
Dependent Claim
14 words
circuit means for detecting the flow of current to ground in said load circuit,
Claim 16
Dependent Claim
49 words
switching means, having opened and closed positions, in said system for disabling the flow of current to saId load circuit when the switching means is in its open position and for enabling the flow of current to said load circuit when switching means is in its closed position, and
Claim 17
Dependent Claim
49 words
switching means, having opened and closed positions, in said system for disabling the flow of current to saId load circuit when the switching means is in its open position and for enabling the flow of current to said load circuit when switching means is in its closed position, and
Claim 18
Dependent Claim
16 words
The combination of claim 1 further including means for creating a ground condition for test purposes.
Claim 19
Dependent Claim
5 words
An electrical distribution system including:
Claim 20
Dependent Claim
5 words
An electrical distribution system including:
Claim 21
Dependent Claim
107 words
means coupled to said detecting means and responsive to the detection of current flow to ground, for controlling said switching means by placing said switching means in its open position for a predetermined period of time when a flow of current to ground is detected, and for placing said switching means in its closed position after the expiration of said predetermined period of time, whereby said switching means cycles between its opened and closed positions while the ground condition exists, said control means further including means for maintaining said switching means in its open position after it has opened and closed for a predetermined number of cycles.
Claim 22
Dependent Claim
107 words
means coupled to said detecting means and responsive to the detection of current flow to ground, for controlling said switching means by placing said switching means in its open position for a predetermined period of time when a flow of current to ground is detected, and for placing said switching means in its closed position after the expiration of said predetermined period of time, whereby said switching means cycles between its opened and closed positions while the ground condition exists, said control means further including means for maintaining said switching means in its open position after it has opened and closed for a predetermined number of cycles.
Claim 23
Dependent Claim
24 words
The system of claim 6 wherein the flow of power is not reestablished if the ground condition persists for a predetermined length of time.
Claim 24
Dependent Claim
15 words
The system of claim 7 wherein said predetermined length of time is about 30 seconds.
Claim 25
Dependent Claim
18 words
The combination of claim 6 further including manual means for reestablishing the flow of power to said load.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-21 | 1974-12-21 | 1975-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-21 | 1978-12-21 | 1979-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-21 | 1982-12-21 | 1983-06-22 | $7700.00 | Window Closed / Lapsed |