GB1453196A - Protection systems for three phase electrical circuits - Google Patents

Protection systems for three phase electrical circuits

Info

Publication number
GB1453196A
GB1453196A GB29173A GB29173A GB1453196A GB 1453196 A GB1453196 A GB 1453196A GB 29173 A GB29173 A GB 29173A GB 29173 A GB29173 A GB 29173A GB 1453196 A GB1453196 A GB 1453196A
Authority
GB
United Kingdom
Prior art keywords
detector
current
operate
circuit
produced
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
Application number
GB29173A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Midland Electric Manufacturing Co Ltd
Original Assignee
Midland Electric Manufacturing Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Midland Electric Manufacturing Co Ltd filed Critical Midland Electric Manufacturing Co Ltd
Priority to GB29173A priority Critical patent/GB1453196A/en
Publication of GB1453196A publication Critical patent/GB1453196A/en
Expired legal-status Critical Current

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
    • H02H3/08—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
    • H02H3/10—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 additionally responsive to some other abnormal electrical conditions
    • H02H3/105—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 additionally responsive to some other abnormal electrical conditions responsive to excess current and fault current to earth
    • 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
    • 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
    • H02H3/347—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 using summation current transformers

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Emergency Protection Circuit Devices (AREA)

Abstract

1453196 Earth fault and overcurrent protection MIDLAND ELECTRIC MFG CO Ltd 29 Nov 1973 [3 Jan 1973] 291/73 Heading H2K A polyphase protective system has a detector such as a current transformer 15 (Fig. 1) arranged so that an output signal is produced at 20 when the vector sum of the currents in conductors 10, 11, 12 exceeds a predetermined value and a second detector such as a current transformer 15 (Fig. 2) arranged so that when the current in conductor 12 exceeds a set value an output signal is produced at 25 which operates a delay device 33, as does the signal produced at 20, and the device 33 after a predetermined time provides an output signal to operate a circuit-breaker 40 to open the circuit through conductors 10, 11, 12. The output from the detector 15 of Fig. 2 may also be fed to a capacitor resistor network 29, 30 which charges to operate a comparator 27 on overvoltage due to excess current. Potentiometers 17 can be used for current setting and comparators 16 may feed monostable multivibrators 21. The delay may be achieved by a circuit 39 providing a signal at say 5 seconds after energization to operate a gate 35 if NOR gate 34 is still operative.
GB29173A 1973-01-03 1973-01-03 Protection systems for three phase electrical circuits Expired GB1453196A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB29173A GB1453196A (en) 1973-01-03 1973-01-03 Protection systems for three phase electrical circuits

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB29173A GB1453196A (en) 1973-01-03 1973-01-03 Protection systems for three phase electrical circuits

Publications (1)

Publication Number Publication Date
GB1453196A true GB1453196A (en) 1976-10-20

Family

ID=9701789

Family Applications (1)

Application Number Title Priority Date Filing Date
GB29173A Expired GB1453196A (en) 1973-01-03 1973-01-03 Protection systems for three phase electrical circuits

Country Status (1)

Country Link
GB (1) GB1453196A (en)

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Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee