US3427505A - Leakage current protection switch with excess current release - Google Patents

Leakage current protection switch with excess current release Download PDF

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Publication number
US3427505A
US3427505A US609850A US3427505DA US3427505A US 3427505 A US3427505 A US 3427505A US 609850 A US609850 A US 609850A US 3427505D A US3427505D A US 3427505DA US 3427505 A US3427505 A US 3427505A
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US
United States
Prior art keywords
release
current
switch
winding
leakage current
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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 - Lifetime
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US609850A
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English (en)
Inventor
Siegfried Biedermann
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UNINORM ANSTALT
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UNINORM ANSTALT
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Publication date
Application filed by UNINORM ANSTALT filed Critical UNINORM ANSTALT
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Publication of US3427505A publication Critical patent/US3427505A/en
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    • 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
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H83/00—Protective switches, e.g. circuit-breaking switches, or protective relays operated by abnormal electrical conditions otherwise than solely by excess current
    • H01H83/20—Protective switches, e.g. circuit-breaking switches, or protective relays operated by abnormal electrical conditions otherwise than solely by excess current operated by excess current as well as by some other abnormal electrical condition
    • H01H83/22—Protective switches, e.g. circuit-breaking switches, or protective relays operated by abnormal electrical conditions otherwise than solely by excess current operated by excess current as well as by some other abnormal electrical condition the other condition being imbalance of two or more currents or voltages
    • H01H83/226—Protective switches, e.g. circuit-breaking switches, or protective relays operated by abnormal electrical conditions otherwise than solely by excess current operated by excess current as well as by some other abnormal electrical condition the other condition being imbalance of two or more currents or voltages with differential transformer
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H71/00—Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
    • H01H71/10—Operating or release mechanisms
    • H01H71/12—Automatic release mechanisms with or without manual release
    • H01H71/24—Electromagnetic mechanisms
    • H01H71/28—Electromagnetic mechanisms with windings acting in conjunction

Definitions

  • the present invention relates to a leakage current protection switch with excess current release.
  • Leakage current protection switches for electric relay systems have hitherto been designed mainly as load switches exercising a protective function only against inadmissible earth leakage currents.
  • the protective switch should provide protection against electric shock by providing protection against leakage currents and should also provide protection against overloading and short circuits.
  • no fully satisfactory solution to the problem of providing this combined protection has been found because combinations of summation current transformers, bimetal releases and short circuit release coils are economically too costly.
  • 1,188,706 there is described an arrangement providing excess current and a short circuit release in a leakage current protection switch in which a summation current transformer is used and measuring members (short circuit magnets, thermal releases) responding to overcurrent or short circuit associated with the individual mains phases close upon release of a circuit which leads via a special working winding (tertiary winding) of the summation current transformer.
  • FIGURE 1 is a basic circuit diagram of a switch according to the present invention.
  • FIG. 2 discloses details of the basic circuit diagram illustrated in FIG. 1;
  • FIG. 3 shows an advantageous construction of the summation current transformer
  • FIG. 4 shows a release curve
  • a leakage current protection switch which works according to one of the known residual magnetic release principles, whereby a release magnet 7 is disposed across two galvanically separated release windings W W One of the two release windings, namely the winding W is excited by the secondary winding of a summation current transformer 1 in conventional manner.
  • the other of the release windings namely the winding W is connected in series with a negative temperature coefficient resistance 2 to form a circuit completely separated electrically from the winding W thus preventing any undue electrical influence on the winding W
  • a resistance 2 is disposed inside the summation current transformer 1 which can be regarded simply as a heat bed, which arrangement constitutes one of the features of the present invention, the temperature of which heat bed represents a measure of the currents in the mains conductors.
  • This circuit, including the resistance 2 and the second release winding W is fed by a voltage derived from the currents in the phase conductors via a current transformer (or several current transformers) 3-.
  • the voltage fed to release winding W and resistance 2 and which represents a measurement of the phase currents is advantageously derived in such a way that the three current transformers 3 in the other leads are connected in a star delta arrangement and supply a direct voltage via a rotating current half-wave rectifier comprising three diodes 4 and a smoothing condenser 5.
  • the direct voltage increases with increase of the phase current irrespective of whether in one, in two, or all three outside leads and conversely decreases with decrease of the phase current.
  • the smoothing condenser 5 can be selected sufiiciently large, so that it is charged irrespective of the number of current conducting outer leads always corresponding to the peak value of the alternating current and thus supplies a current measurement independent of the number of loaded or overloaded conductors. If the leakage current release is constructed 3 as a stop magnet or holding magnet (for example, as described in Austrain patent specification No. 244,427) attention must be paid to the correct polarity of the release winding W In accordance with the basic concept of the present invention, in the present release switch, the negative temperature coefiicient resistannce 2, decisive for providing the increased current in the release winding W to effect the excess current release, is located in the geometric center of the summation current transformer 1.
  • the summation current transformer 1 is a ring core transformer with primary winding number equal to one, whereby the ring core 8 closely surrounds the mains leads 9 which are threaded through it.
  • a suitable development of the switch described in order to attain independence from greatly fluctuating ambient temperatures consists in that in the circuit of the second excess current excited release winding W compensating switch elements 6 of the same or similar temperature characteristic as the resistance 2 are arranged in the circuit, as shown in broken lines in FIG. 1, and are located so that their resistance values are determined primarily by the ambient temperature.
  • the leakage current protection switch described is suitable as a motor protection switch.
  • a leakage current protection switch with excess current release for a protected circuit comprising a first magnetic release
  • a summation current transformer connected in circuit with said magnetic release, to provide leakage current protection and to provide excess current protection
  • said second magnetic release being fed via said transformers with a voltage dependent upon currents flowing in said phase leads.
  • said summation current transformer is formed as a ring core transformer having a primary winding number equal to one, and whereby said ring core closely surrounds the main leads which are threaded through it.
  • the switch as set forth in claim 4, which includes at least one compensating resistance, having at least similar temperature characteristics as said negative temperature coefiicient resistance, is disposed in the circuit of said release winding and so located that its resistance is determined primarily by the ambient temperature.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Emergency Protection Circuit Devices (AREA)
  • Protection Of Transformers (AREA)
US609850A 1966-01-25 1967-01-17 Leakage current protection switch with excess current release Expired - Lifetime US3427505A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
AT68466A AT259054B (de) 1966-01-25 1966-01-25 Fehlerstromschutzschalter mit zusätzlicher Überstromauslösung

Publications (1)

Publication Number Publication Date
US3427505A true US3427505A (en) 1969-02-11

Family

ID=3497081

Family Applications (1)

Application Number Title Priority Date Filing Date
US609850A Expired - Lifetime US3427505A (en) 1966-01-25 1967-01-17 Leakage current protection switch with excess current release

Country Status (8)

Country Link
US (1) US3427505A (fr)
AT (1) AT259054B (fr)
CH (1) CH453477A (fr)
DE (1) DE1588896B2 (fr)
DK (1) DK123896B (fr)
FR (1) FR1508704A (fr)
GB (1) GB1136836A (fr)
SE (1) SE304550B (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3599043A (en) * 1967-12-19 1971-08-10 Uninorm Anstalt Electrical circuit breakers
US4044395A (en) * 1976-08-02 1977-08-23 General Electric Company Ground fault protection system
USRE30304E (en) * 1976-08-02 1980-06-10 General Electric Company Ground fault protection system
DE29509098U1 (de) * 1995-06-01 1995-08-03 Siemens Ag Koppelsystem
WO2000016459A1 (fr) * 1998-09-16 2000-03-23 Siemens Aktiengesellschaft Dispositif de protection contre un courant differentiel residuel avec disjoncteur a surintensite

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2210000B1 (fr) * 1972-12-13 1976-01-30 Saparel Fr
DE2428993A1 (de) * 1974-06-15 1976-01-02 Lauerer Friedrich Redundanz-fehlerstromschutzschalter
DE3136412A1 (de) * 1981-09-14 1983-03-24 Siemens AG, 1000 Berlin und 8000 München Kombinierter fehlerstromschutz- und leitungsschutzschalter
CH682526A5 (de) * 1990-10-27 1993-09-30 Abb Patent Gmbh Ableitertrennschalter.
EP0495771B1 (fr) * 1991-01-16 1997-01-02 Felten & Guilleaume Austria Ag Disjoncteur différentiel
AT408044B (de) * 1991-05-29 2001-08-27 Biegelmeier Gottfried Fehlerstromschutzschalter
ZA947576B (en) * 1993-10-27 1995-05-15 Circuit Breaker Ind An electrical protection device
WO1995026586A1 (fr) * 1994-03-28 1995-10-05 Felten & Guilleaume Austria Ag Protection de disjoncteurs contre les surcharges thermiques
GB2303980B (en) * 1995-08-02 1997-09-10 Sheir Chun Lam Circuit breaker
DE19834973A1 (de) * 1998-08-03 2000-02-10 Siemens Ag Elektrische Installationseinrichtung mit wärmeempfindlichem Element in einer Abschaltkette

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB391546A (en) * 1931-01-15 1933-05-04 Gen Electric Improvements in and relating to protective devices for electric distribution systems
GB675514A (en) * 1949-08-26 1952-07-09 Vickers Electrical Co Ltd Improvements in earth leakage protection for polyphase electrical circuits
US3158785A (en) * 1961-07-03 1964-11-24 Charbonnages De France Devices for detecting earth faults in electric distribution networks
US3214638A (en) * 1959-10-02 1965-10-26 Moser Robert Ground responsive protective system

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB391546A (en) * 1931-01-15 1933-05-04 Gen Electric Improvements in and relating to protective devices for electric distribution systems
GB675514A (en) * 1949-08-26 1952-07-09 Vickers Electrical Co Ltd Improvements in earth leakage protection for polyphase electrical circuits
US3214638A (en) * 1959-10-02 1965-10-26 Moser Robert Ground responsive protective system
US3158785A (en) * 1961-07-03 1964-11-24 Charbonnages De France Devices for detecting earth faults in electric distribution networks

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3599043A (en) * 1967-12-19 1971-08-10 Uninorm Anstalt Electrical circuit breakers
US4044395A (en) * 1976-08-02 1977-08-23 General Electric Company Ground fault protection system
USRE30304E (en) * 1976-08-02 1980-06-10 General Electric Company Ground fault protection system
DE29509098U1 (de) * 1995-06-01 1995-08-03 Siemens Ag Koppelsystem
WO2000016459A1 (fr) * 1998-09-16 2000-03-23 Siemens Aktiengesellschaft Dispositif de protection contre un courant differentiel residuel avec disjoncteur a surintensite

Also Published As

Publication number Publication date
DE1588896A1 (de) 1971-02-04
DK123896B (da) 1972-08-14
CH453477A (de) 1968-06-14
AT259054B (de) 1967-12-27
GB1136836A (en) 1968-12-18
DE1588896B2 (de) 1971-06-24
FR1508704A (fr) 1968-01-05
SE304550B (fr) 1968-09-30

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