GB1020862A - Improvements relating to protective systems - Google Patents
Improvements relating to protective systemsInfo
- Publication number
- GB1020862A GB1020862A GB1111661A GB1111661A GB1020862A GB 1020862 A GB1020862 A GB 1020862A GB 1111661 A GB1111661 A GB 1111661A GB 1111661 A GB1111661 A GB 1111661A GB 1020862 A GB1020862 A GB 1020862A
- Authority
- GB
- United Kingdom
- Prior art keywords
- switch
- resistor
- current
- earth
- transformer
- 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
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/16—Measuring impedance of element or network through which a current is passing from another source, e.g. cable, power line
- G01R27/18—Measuring resistance to earth, i.e. line to ground
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Emergency Protection Circuit Devices (AREA)
Abstract
1,020,862. Protective arrangements. A. REYROLLE & CO. Ltd. April 26, 1962 [March 27, 1961], No. 11116/61. Heading H2K. A protective arrangement for checking the insulation from earth of a conductor, when it is disconnected by a switch 13 from a supply, comprises two impedances 45, 46 connected in series in a testing circuit between the conductor and earth, and means operative when the switch is closed for passing direct currents through the impedances such as to produce equal and opposite potential differences across them. One direct current is derived from.the supply side and the other from the load side of the switch so that when the switch is open the latter current ceases and the former current tends to pass between the conductor and earth a current representative of the insulation resistance. Thus in the polyphase system shown, an earth fault on one or more of the conductors 14 ... 16, when the switch 13 is open, enables the potential produced across the resistor 45 by transformer 51, 47 and rectifiers 49, to cause current to flow through a resistor 36, a diode 35, a transformer 20, the conductors and the fault path. The voltage produced across the resistor 36 causes a transistor trigger stage 60, 62 to change its state to render an amplifying transistor 69 conductive. A relay 71 is energized and is effective to operate a warning device or to prevent the closing of the switch 13. When the switch 13 is closed, the potential produced across the resistor 46 by a transformer 48, 52 and rectifiers 50 opposes that across the resistor 45. Since there is no resultant D.C. potential at point 43, the transistors 60, 62 and 69 are not energized. Should an earth fault now occur, the A.C. flowing through the testing circuit produces a rectified component across a resistor 38 which biases a transistor 75 to conduction. This causes a transistor 76 to cut-off so deenergizing a relay 77 which can be arranged to actuate a warning 'device and/or open the switch 13. The secondary windings 24 ... 26 of the transformer 20 are connected in delta with a resistor 27 in series in the delta to limit the A.C. earth fault current as claimed in Specification 1,020,863.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1111661A GB1020862A (en) | 1961-03-27 | 1961-03-27 | Improvements relating to protective systems |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB1111661A GB1020862A (en) | 1961-03-27 | 1961-03-27 | Improvements relating to protective systems |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1020862A true GB1020862A (en) | 1966-02-23 |
Family
ID=9980335
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB1111661A Expired GB1020862A (en) | 1961-03-27 | 1961-03-27 | Improvements relating to protective systems |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB1020862A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2463977A2 (en) | 2010-12-09 | 2012-06-13 | Solaredge Technologies Ltd. | Disconnection of a photovoltaic string carrying direct current power |
-
1961
- 1961-03-27 GB GB1111661A patent/GB1020862A/en not_active Expired
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP2463977A2 (en) | 2010-12-09 | 2012-06-13 | Solaredge Technologies Ltd. | Disconnection of a photovoltaic string carrying direct current power |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4151575A (en) | Motor protective device | |
GB1060643A (en) | Electrical fault detection arrangement | |
US3558980A (en) | Automatic ground fault circuit interrupter | |
GB1133750A (en) | Electrical barrier device | |
GB1021502A (en) | Improvements in and relating to electrical protective relay systems | |
GB1237342A (en) | Electric protective circuits | |
GB1007794A (en) | Improvements in devices for detecting earth faults in electric distribution networks | |
GB1250854A (en) | ||
GB1020862A (en) | Improvements relating to protective systems | |
GB1394455A (en) | Ground fault detectors | |
GB1254587A (en) | Circuits and methods for protecting electrical machining apparatus | |
GB1097809A (en) | Improved circuit breaker control system | |
GB1215248A (en) | Arrangements for short-circuit indication or protection in unidirectional-voltage supply systems | |
GB1309820A (en) | Gatecontrolled phase failure protection circuit | |
GB1405357A (en) | Apparatuses for detecting failure in a potentiometer circuit | |
US3504234A (en) | Electric control system | |
US3162790A (en) | Transistor relay circuit | |
GB981892A (en) | Earth fault circuit-breaker | |
US3079532A (en) | Protection device for reverse polarity in d.-c. generators | |
GB1010828A (en) | Improvements relating to earth leakage protection | |
GB1352913A (en) | Transistor amplifier with overload protection | |
GB905127A (en) | Improvements in or relating to electric guard circuits | |
GB1226353A (en) | ||
GB1067864A (en) | Fail to safe earth leakage detector circuits | |
GB1138615A (en) | Electrical protective relay arrangement |