GB376250A - Improvements in automatic protective systems for alternating current circuits - Google Patents

Improvements in automatic protective systems for alternating current circuits

Info

Publication number
GB376250A
GB376250A GB609031A GB609031A GB376250A GB 376250 A GB376250 A GB 376250A GB 609031 A GB609031 A GB 609031A GB 609031 A GB609031 A GB 609031A GB 376250 A GB376250 A GB 376250A
Authority
GB
United Kingdom
Prior art keywords
fuse
current
main
circuit
secondaries
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
GB609031A
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.)
Johnson and Phillips Ltd
Original Assignee
Johnson and Phillips 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 Johnson and Phillips Ltd filed Critical Johnson and Phillips Ltd
Priority to GB609031A priority Critical patent/GB376250A/en
Publication of GB376250A publication Critical patent/GB376250A/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
    • H02H3/26—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

Landscapes

  • Protection Of Transformers (AREA)
  • Emergency Protection Circuit Devices (AREA)

Abstract

376,250. Protective cut-out arrangements. JOHNSON & PHILLIPS, Ltd., Victoria Works, Charlton, and STIGANT, S. A., 41, Crantock Road, Catford, both in London. Feb. 26, 1931, No. 6090. [Class 38 (v).] In the protection of A.C. circuits, particularly overhead lines, against earth fault, the several phases (or the outgoing and return lines in the case of a single-phase circuit) are taken through a common transformer core which is provided with secondaries equal in number to the lines, each secondary being connected in series with the operating element of a circuit disconnecting device located in each of the lines via an auxiliary circuit disconnecting device. The primary windings are arranged so that with healthy conditions they balance one another whereas in the event of an earth fault the secondaries increase the current through the operating element of the disconnecting device and open the circuit. The protective system is applicable mainly to a supply system with an earthed neutral although this is not necessary with extra high voltage circuits. In the arrangement shown in the Figure for a three-phase circuit using fuses FA, FB, FC as the disconnecting devices, the transformer core has three primary windings PA, PB, PC and three secondaries SA, SB, SC. The secondaries are each connected in series with a main circuit fuse through an auxiliary fuse such as FAI. In the event of an earth fault, the current in the secondary such as SA assists the main current through the fuse FA to cause its rupture. The main circuit is completely interrupted when the auxiliary fuse ruptures subsequent to the rupture of the main fuse. The main line current through the main fuse may normally be neutralized by the current from a current transformer CTA in the main line thus leaving only the currents of the balancing transformer to blow the main line fuses. In a modification, one secondary only on the balancing transformer is used and is connected to an intermediate core having a number of secondaries equal to the number of lines.
GB609031A 1931-02-26 1931-02-26 Improvements in automatic protective systems for alternating current circuits Expired GB376250A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB609031A GB376250A (en) 1931-02-26 1931-02-26 Improvements in automatic protective systems for alternating current circuits

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB609031A GB376250A (en) 1931-02-26 1931-02-26 Improvements in automatic protective systems for alternating current circuits

Publications (1)

Publication Number Publication Date
GB376250A true GB376250A (en) 1932-06-27

Family

ID=9808184

Family Applications (1)

Application Number Title Priority Date Filing Date
GB609031A Expired GB376250A (en) 1931-02-26 1931-02-26 Improvements in automatic protective systems for alternating current circuits

Country Status (1)

Country Link
GB (1) GB376250A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE28996E (en) * 1967-04-14 1976-10-05 Harvey Hubbell Incorporated Ground leakage differential protective apparatus

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USRE28996E (en) * 1967-04-14 1976-10-05 Harvey Hubbell Incorporated Ground leakage differential protective apparatus

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