GB679789A - Improvements in and relating to earth leakage protection for single phase a.c. circuits - Google Patents
Improvements in and relating to earth leakage protection for single phase a.c. circuitsInfo
- Publication number
- GB679789A GB679789A GB2397450A GB2397450A GB679789A GB 679789 A GB679789 A GB 679789A GB 2397450 A GB2397450 A GB 2397450A GB 2397450 A GB2397450 A GB 2397450A GB 679789 A GB679789 A GB 679789A
- Authority
- GB
- United Kingdom
- Prior art keywords
- relay
- fault
- contacts
- contactor
- earth
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
- H02H3/16—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to fault current to earth, frame or mass
- H02H3/162—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to fault current to earth, frame or mass for ac systems
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B28—WORKING CEMENT, CLAY, OR STONE
- B28D—WORKING STONE OR STONE-LIKE MATERIALS
- B28D1/00—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor
- B28D1/14—Working stone or stone-like materials, e.g. brick, concrete or glass, not provided for elsewhere; Machines, devices, tools therefor by boring or drilling
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B28—WORKING CEMENT, CLAY, OR STONE
- B28D—WORKING STONE OR STONE-LIKE MATERIALS
- B28D7/00—Accessories specially adapted for use with machines or devices of the preceding groups
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Mining & Mineral Resources (AREA)
- Power Engineering (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
679,789. Protective cut-out arrangements. BROOKE, W., and BALDWIN, H. T. Sept. 30, 1950. No. 23974/50. Class 38 (v). An earth-leakage protective system for single-phase A.C. circuits has an earth-leakage relay R1, which on the incidence of an earth fault is energized from a rectifier connected between earth and an artificial neutral point, a second relay R2 being energized from an auxiliary supply by the closing of the earth-leakage relay to open the contactor switch C controlling the protected circuit. In the Figure, plug points Z1, Z2 are supplied from a transformer T through the contactor C which has its operating coil F supplied from lines L1, L2 through a full-wave rectifier D2 and the normallyclosed contacts RC, RE of relays R1, R3. A transformer A<SP>1</SP> has its primary winding centretapped to provide an artificial neutral point AP which is connected to earth through a fullwave rectifier D1 which supplies the operating coil of the leakage relay R1. As soon as the transformer T is energized the contactor C closes and at C3 inserts an economy resistance G in series with the contactor operating coil F. If now an apparatus, such as a drill Y, connected to a plug point, should develop an earth fault as indicated at W, fault current will flow from line L2, through a conductor U, the fault W, earth conductors V and X, a connection 2, the rectifier D1 and the coil of relay R1 to the neutral point AP. The relay R1 closes its contacts RA to complete a circuit from secondary winding AS1 of the transformer A1 through a conductor 6, a rectifier D3, a connection 10, the coil of relay R2, the contacts RA, a connection 9, the rectifier D3 and a connection 5. The relay R2 now opens its contacts RC to deenergize the coil F of the contactor, which opens. The relay R2 also closes contacts RB, so that should the fault W persist, a circuit is completed from the secondary winding AS1 through the rectifier D3, a connection 101, a centretapped neutral point impedance A2, the conductor U, the fault W, connections V, X and 13, the relay contacts RB, a connection 12, the coil of relay R3, the rectifier D3 and the connection 5. The coil of relay R3 is thus energized by a D.C. current flowing through the fault and the relay R3 opens its contacts RE to prevent the reclosure of the contactor C so long as the fault remains. The relay R3 closes contacts RD to maintain a holding circuit for itself since the relays R1, R2 open when the contactor C opens to disconnect the plugs (and the fault) from the supply. The relay R3 when energized also closes contacts RF to light a fault indicating lamp E. When the fault is removed the relay R3 is de-energized and the contactor recloses automatically as previously described or under the control of a push button (not shown).
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB2397450A GB679789A (en) | 1950-09-30 | 1950-09-30 | Improvements in and relating to earth leakage protection for single phase a.c. circuits |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB2397450A GB679789A (en) | 1950-09-30 | 1950-09-30 | Improvements in and relating to earth leakage protection for single phase a.c. circuits |
Publications (1)
Publication Number | Publication Date |
---|---|
GB679789A true GB679789A (en) | 1952-09-24 |
Family
ID=10204380
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB2397450A Expired GB679789A (en) | 1950-09-30 | 1950-09-30 | Improvements in and relating to earth leakage protection for single phase a.c. circuits |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB679789A (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3168682A (en) * | 1961-02-10 | 1965-02-02 | Aston L Moore | Supervisory system |
US3344313A (en) * | 1965-04-02 | 1967-09-26 | Electronic Safety Controls Inc | Load responsive ungrounded electrical distribution system |
US3386004A (en) * | 1965-08-09 | 1968-05-28 | Sentry Inc | Low voltage safety circuit for electric power units |
US3407336A (en) * | 1966-08-11 | 1968-10-22 | Physio Control Corp | Electronic ground-absence detector and protective device |
US4525764A (en) * | 1982-06-10 | 1985-06-25 | Titus Charles H | System for disconnecting an electrical power source from a load |
EP0183644A2 (en) * | 1984-11-29 | 1986-06-04 | HILTI Aktiengesellschaft | Method for making recesses |
US7944213B2 (en) | 2009-09-24 | 2011-05-17 | General Electric Company | Ground fault detection device |
-
1950
- 1950-09-30 GB GB2397450A patent/GB679789A/en not_active Expired
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3168682A (en) * | 1961-02-10 | 1965-02-02 | Aston L Moore | Supervisory system |
US3344313A (en) * | 1965-04-02 | 1967-09-26 | Electronic Safety Controls Inc | Load responsive ungrounded electrical distribution system |
US3386004A (en) * | 1965-08-09 | 1968-05-28 | Sentry Inc | Low voltage safety circuit for electric power units |
US3407336A (en) * | 1966-08-11 | 1968-10-22 | Physio Control Corp | Electronic ground-absence detector and protective device |
US4525764A (en) * | 1982-06-10 | 1985-06-25 | Titus Charles H | System for disconnecting an electrical power source from a load |
EP0183644A2 (en) * | 1984-11-29 | 1986-06-04 | HILTI Aktiengesellschaft | Method for making recesses |
EP0183644A3 (en) * | 1984-11-29 | 1988-01-20 | Hilti Aktiengesellschaft | Method for making recesses |
US7944213B2 (en) | 2009-09-24 | 2011-05-17 | General Electric Company | Ground fault detection device |
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