GB741423A - Improvements in or relating to electric protective systems - Google Patents
Improvements in or relating to electric protective systemsInfo
- Publication number
- GB741423A GB741423A GB1878652A GB1878652A GB741423A GB 741423 A GB741423 A GB 741423A GB 1878652 A GB1878652 A GB 1878652A GB 1878652 A GB1878652 A GB 1878652A GB 741423 A GB741423 A GB 741423A
- Authority
- GB
- United Kingdom
- Prior art keywords
- coil
- relay
- circulating
- contacts
- current
- 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
- H02H3/26—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 difference between voltages or between currents; responsive to phase angle between voltages or between currents
- H02H3/28—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 difference between voltages or between currents; responsive to phase angle between voltages or between currents involving comparison of the voltage or current values at two spaced portions of a single system, e.g. at opposite ends of one line, at input and output of apparatus
- H02H3/30—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 difference between voltages or between currents; responsive to phase angle between voltages or between currents involving comparison of the voltage or current values at two spaced portions of a single system, e.g. at opposite ends of one line, at input and output of apparatus using pilot wires or other signalling channel
- H02H3/307—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 difference between voltages or between currents; responsive to phase angle between voltages or between currents involving comparison of the voltage or current values at two spaced portions of a single system, e.g. at opposite ends of one line, at input and output of apparatus using pilot wires or other signalling channel involving comparison of quantities derived from a plurality of phases, e.g. homopolar quantities; using mixing transformers
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
741,423. Protective cut-out arrangements. GENERAL ELECTRIC CO., Ltd., and GOODINGS; D. B. July 24, 1953 [July 24, 1952; Oct. 20, 1952], Nos. 18786/52 and 26334/52. Class 38(5) In a balanced voltage protective system, the integrity of the land lines or pilot wires is checked by a circulating direct current, means being provided responsive to a change in the value of the circulating current from normal for rendering the system unresponsive to supply system faults. As shown in the drawing of the first Provisional Specification, a battery 20 is connected directly to one pilot wire 15 and through relay coils 21, 24 to the other pilot wire 14, the return including a resistance 30 and coil 31 of a relay 32. The effect of coil 24 is normally balanced by that of a coil 26, so that contacts 29 of this relay (25) are normally closed. Similarly, coil 31 (in relay 32) is normally balanced by a coil 34 fed from a separate battery 35, so that contacts 33, 37 are normally closed. In the event of a short circuit, open circuit or reversal of the pilot wires, relays 25, 32 become unbalanced and contacts 29, 37 open to prevent operation of comparison means 13, and contact 33 opens to break the circuit of the the circulating current. The coil 21 changes over its contact from contacts 28 to 18 in the event of a reduction of the insulation resistance and so de-energizes coil 26; at the same time a resistance 19 is put in series with coil 31 so upsetting the balance of relay 32 also. In a modification, the relay coil is omitted and coils 24, 26 act as balanced restraining windings in a relay also having an operating winding fed by a current proportional to the circulating A.C. in the pilots, and a further restraining winding responsive to the current in the system to be protected. Coils 31, 34 are similarly arranged at the other end of the system. A further relay corresponding to relay 32 has a contact in series in the circuit of the circulating D.C. It is stated that an indication may also be given on failure of the the pilot wires. Specification 699,638 is referred to.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1878652A GB741423A (en) | 1952-07-24 | 1952-07-24 | Improvements in or relating to electric protective systems |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1878652A GB741423A (en) | 1952-07-24 | 1952-07-24 | Improvements in or relating to electric protective systems |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB741423A true GB741423A (en) | 1955-12-07 |
Family
ID=10118409
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1878652A Expired GB741423A (en) | 1952-07-24 | 1952-07-24 | Improvements in or relating to electric protective systems |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB741423A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1987002836A1 (en) * | 1985-10-31 | 1987-05-07 | The South East Queensland Electricity Board | Intertripping system |
-
1952
- 1952-07-24 GB GB1878652A patent/GB741423A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1987002836A1 (en) * | 1985-10-31 | 1987-05-07 | The South East Queensland Electricity Board | Intertripping system |
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