FR2366726A1 - Protective device for AC system with unearthed neutral line - uses test current injected between neutral and earth and potential difference compared with mains potential difference - Google Patents

Protective device for AC system with unearthed neutral line - uses test current injected between neutral and earth and potential difference compared with mains potential difference

Info

Publication number
FR2366726A1
FR2366726A1 FR7629991A FR7629991A FR2366726A1 FR 2366726 A1 FR2366726 A1 FR 2366726A1 FR 7629991 A FR7629991 A FR 7629991A FR 7629991 A FR7629991 A FR 7629991A FR 2366726 A1 FR2366726 A1 FR 2366726A1
Authority
FR
France
Prior art keywords
neutral
potential difference
earth
unearthed
mains
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.)
Granted
Application number
FR7629991A
Other languages
French (fr)
Other versions
FR2366726B1 (en
Inventor
Guy Guegan
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.)
SOCHATA SNECMA
Original Assignee
SOCHATA SNECMA
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 SOCHATA SNECMA filed Critical SOCHATA SNECMA
Priority to FR7629991A priority Critical patent/FR2366726A1/en
Priority to DE19772744177 priority patent/DE2744177A1/en
Publication of FR2366726A1 publication Critical patent/FR2366726A1/en
Application granted granted Critical
Publication of FR2366726B1 publication Critical patent/FR2366726B1/fr
Granted 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
    • H02H3/16—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
    • H02H3/165—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 for three-phase systems
    • 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
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections
    • G01R31/52—Testing for short-circuits, leakage current or ground faults
    • 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
    • H02H3/17—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 by means of an auxiliary voltage injected into the installation to be protected

Landscapes

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

Abstract

The protective system for a multiphase AC distribution system with unearthed neutral prevents overheating of the neutral by a "double short" current overload. It reduces the fault current to a safe value and trip the circuit if the reduction is not effected within a preset time. A test current at a frequency differing from that of the mains (this may be direct current) is injected between neutral and earth from a constant voltage source through a limiting resistance, and the potential difference between the neutral and earth is measured at both frequencies. From the difference between these values a criterion is provided for the triggering of an alarm.
FR7629991A 1976-10-01 1976-10-01 Protective device for AC system with unearthed neutral line - uses test current injected between neutral and earth and potential difference compared with mains potential difference Granted FR2366726A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
FR7629991A FR2366726A1 (en) 1976-10-01 1976-10-01 Protective device for AC system with unearthed neutral line - uses test current injected between neutral and earth and potential difference compared with mains potential difference
DE19772744177 DE2744177A1 (en) 1976-10-01 1977-09-30 DEVICE FOR PROTECTING ELECTRICAL SYSTEMS IN WHICH THE NEUTRAL CONDUCTOR IS NOT DIRECT TO EARTH AGAINST HEATING OF THE NEUTRAL CONDUCTOR

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7629991A FR2366726A1 (en) 1976-10-01 1976-10-01 Protective device for AC system with unearthed neutral line - uses test current injected between neutral and earth and potential difference compared with mains potential difference

Publications (2)

Publication Number Publication Date
FR2366726A1 true FR2366726A1 (en) 1978-04-28
FR2366726B1 FR2366726B1 (en) 1979-03-02

Family

ID=9178426

Family Applications (1)

Application Number Title Priority Date Filing Date
FR7629991A Granted FR2366726A1 (en) 1976-10-01 1976-10-01 Protective device for AC system with unearthed neutral line - uses test current injected between neutral and earth and potential difference compared with mains potential difference

Country Status (2)

Country Link
DE (1) DE2744177A1 (en)
FR (1) FR2366726A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03270631A (en) * 1990-03-16 1991-12-02 Mitsubishi Electric Corp 4-pole circuit breaker

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR62607E (en) * 1951-02-07 1955-06-15 Merlin Gerin Insulation monitoring device
FR87724E (en) * 1964-05-23 1966-07-22 Comp Generale Electricite Electrical insulation measuring device
FR1519717A (en) * 1967-02-20 1968-04-05 Christ Et Philippou S A Device for fault finding in electrical installations

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR62607E (en) * 1951-02-07 1955-06-15 Merlin Gerin Insulation monitoring device
FR87724E (en) * 1964-05-23 1966-07-22 Comp Generale Electricite Electrical insulation measuring device
FR1519717A (en) * 1967-02-20 1968-04-05 Christ Et Philippou S A Device for fault finding in electrical installations

Also Published As

Publication number Publication date
DE2744177A1 (en) 1978-04-06
FR2366726B1 (en) 1979-03-02

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Legal Events

Date Code Title Description
ST Notification of lapse