GB1292142A - Fault protection devices - Google Patents
Fault protection devicesInfo
- Publication number
- GB1292142A GB1292142A GB4609269A GB4609269A GB1292142A GB 1292142 A GB1292142 A GB 1292142A GB 4609269 A GB4609269 A GB 4609269A GB 4609269 A GB4609269 A GB 4609269A GB 1292142 A GB1292142 A GB 1292142A
- Authority
- GB
- United Kingdom
- Prior art keywords
- circuit
- capacitor
- current
- transistor
- output
- 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
- H02H3/32—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 corresponding points in different conductors of a single system, e.g. of currents in go and return conductors
- H02H3/34—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 corresponding points in different conductors of a single system, e.g. of currents in go and return conductors of a three-phase system
-
- 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
- H02H3/08—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 excess current
- H02H3/093—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 excess current with timing means
Landscapes
- Emergency Protection Circuit Devices (AREA)
Abstract
1292142 Protective arrangements WESTINGHOUSE ELECTRIC CORP 7 Oct 1969 [7 Oct 1968 (3)] 46092/69 Heading H2K An overload protective arrangement comprises a level detecting circuit 260 connected to receive rectified pulses having the same configuration as, and a magnitude directly proportional to, the half wave portions of the current in a protected A.C. circuit and producing an output signal instantaneously when the pulses exceed a predetermined value, a timing circuit to maintain the output signal for a predetermined time when the magnitude of the pulses falls below the predetermined value, and pulse generating means 230 controlling the charging of a timing capacitor C4 when permitted to do so by the output signal. In the arrangement shown, bridge rectifiers 22, 24, 26 are connected to current transforming arrangements of a protected three phase network (not shown) and to current auctioneering circuits 110, 120 to provide output signals V1, V2 proportional to the largestline current. The bridge rectifiers are also connected to a power supply circuit comprising a storage capacitor C13 and diodes D23, Z1, Z2, D25 to provide operating supply potentials P1 ... P3. A control circuit 150 prevents operation of the arrangement until the charge on the capacitor C13 is sufficient. A transistor Q5 provides a signal proportional to the largest current to a pulse generator Q4 to produce a pulse signal having a frequency dependent on the magnitude of the current periodically to render non-conducting a transistor Q7 which shunts the signal from a transistor Q6 away from the timing capacitor C4. Since the signal from the transistor Q6 is proportional to the current, the charging of the capacitor C4 will depend on the square of the largest line current. The level detector 260 comprises transistors Q8, Q9 and its timing circuit is formed by a capacitor C5, the output signal from the detector rendering a shunting transistor Q10 non-conductive so that the capacitor C4 is permitted to charge. After a relatively long time delay the capacitor C4 is charged sufficiently to cause an output circuit 410 to render a controlled rectifier Q17 conductive to energize the trip coil (not shown) of a circuit breaker. An auxiliary pulse generating circuit 240 may be provided to increase the sensitivity by periodically raising the voltage at the capacitor C4. An instantaneous tripping circuit 300 comprises a transistor Q18 which provides an output signal through an isolating diode D40 to the output circuit when a high line current occurs on the closing of the circuit-breaker contacts before the contacts are latched in. When the contacts are latched, auxiliary contacts AC1 close to render the circuit 300 inoperative. A short delay tripping circuit 500 comprises a level detecting circuit, with transistors Q11, Q12 and a capacitor C6, which permits the charging of a capacitor C7 when the line current exceeds a predetermined high value. The capacitor C7 is connected via an isolating diode D37 to the output circuit 410. A circuit 600 responsive to ground faults comprises a bridge rectifier D1 ... D4 connected to a ground current transformer (not shown), the rectifier being connected by a resistor R28 to the conductor P1 to charge the capacitor C13, Fig. 2, to provide the operating potentials, and by a resistor R26 to a level detecting circuit 610. When the ground fault current reaches a predetermined level, the circuit 610 permits a capacitor C10 to charge and after a fixed time delay, the voltage across the capacitor causes the operation of the output circuit 410. The output of the level detecting circuit 610 is also applied through a diode D42 to the transistor Q10 to render it non-conductive so that it does not prevent operation of the output circuit 410.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US76558368A | 1968-10-07 | 1968-10-07 | |
US76558268A | 1968-10-07 | 1968-10-07 | |
US76555268A | 1968-10-07 | 1968-10-07 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1292142A true GB1292142A (en) | 1972-10-11 |
Family
ID=27419612
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB2308672A Expired GB1292143A (en) | 1968-10-07 | 1969-10-07 | Fault protection devices |
GB4609269A Expired GB1292142A (en) | 1968-10-07 | 1969-10-07 | Fault protection devices |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB2308672A Expired GB1292143A (en) | 1968-10-07 | 1969-10-07 | Fault protection devices |
Country Status (5)
Country | Link |
---|---|
BE (1) | BE739905A (en) |
BR (1) | BR6913083D0 (en) |
ES (1) | ES371934A1 (en) |
FR (1) | FR2020078B1 (en) |
GB (2) | GB1292143A (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2000400A (en) * | 1977-06-23 | 1979-01-04 | Matthews G | Overload protection circuit |
DE3009581A1 (en) * | 1979-03-16 | 1980-09-25 | Gen Electric | STATIC MOMENT OVERCURRENT RELAY WITH SMALL TRANSIENTER SENSITIVITY |
GB2135146A (en) * | 1983-01-31 | 1984-08-22 | Gen Electric | I2t protection systems |
GB2140633A (en) * | 1983-04-29 | 1984-11-28 | Plessey Co Plc | Load tripping circuits |
-
1969
- 1969-09-26 ES ES371934A patent/ES371934A1/en not_active Expired
- 1969-10-06 BE BE739905D patent/BE739905A/xx unknown
- 1969-10-07 GB GB2308672A patent/GB1292143A/en not_active Expired
- 1969-10-07 GB GB4609269A patent/GB1292142A/en not_active Expired
- 1969-10-07 FR FR6934239A patent/FR2020078B1/fr not_active Expired
- 1969-10-07 BR BR21308369A patent/BR6913083D0/en unknown
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2000400A (en) * | 1977-06-23 | 1979-01-04 | Matthews G | Overload protection circuit |
DE3009581A1 (en) * | 1979-03-16 | 1980-09-25 | Gen Electric | STATIC MOMENT OVERCURRENT RELAY WITH SMALL TRANSIENTER SENSITIVITY |
GB2135146A (en) * | 1983-01-31 | 1984-08-22 | Gen Electric | I2t protection systems |
GB2140633A (en) * | 1983-04-29 | 1984-11-28 | Plessey Co Plc | Load tripping circuits |
Also Published As
Publication number | Publication date |
---|---|
BR6913083D0 (en) | 1973-01-11 |
ES371934A1 (en) | 1971-11-16 |
FR2020078B1 (en) | 1973-05-25 |
BE739905A (en) | 1970-03-16 |
FR2020078A1 (en) | 1970-07-10 |
GB1292143A (en) | 1972-10-11 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed | ||
PLNP | Patent lapsed through nonpayment of renewal fees |