EP0834209A1 - Reseau de distribution d'energie electrique pour batiments - Google Patents

Reseau de distribution d'energie electrique pour batiments

Info

Publication number
EP0834209A1
EP0834209A1 EP96914315A EP96914315A EP0834209A1 EP 0834209 A1 EP0834209 A1 EP 0834209A1 EP 96914315 A EP96914315 A EP 96914315A EP 96914315 A EP96914315 A EP 96914315A EP 0834209 A1 EP0834209 A1 EP 0834209A1
Authority
EP
European Patent Office
Prior art keywords
casing
power distribution
distribution unit
thermal sensor
electrical power
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.)
Withdrawn
Application number
EP96914315A
Other languages
German (de)
English (en)
Inventor
David Eardley Garrard
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Publication of EP0834209A1 publication Critical patent/EP0834209A1/fr
Withdrawn legal-status Critical Current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
    • H02H3/085—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 making use of a thermal sensor, e.g. thermistor, heated by the excess current
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B17/00—Fire alarms; Alarms responsive to explosion
    • G08B17/06—Electric actuation of the alarm, e.g. using a thermally-operated switch

Definitions

  • This invention relates to an electric power distribution unit for buildings including a safety device.
  • a large proportion of fires in domestic premises are caused by electrical faults. Of these, a large proportion originate in the region of the distribution device such as a fuse box, circuit breaker unit or the like. Fires will, for example, be caused by a poor connection in such a unit. It is therefore good and common practice to mount a smoke alarm in the vicinity of the fuse box or circuit breaker unit to detect any smoke which results from a fire at the unit. So long as the smoke detector is and remains in sound working condition, and there is someone in the building, this then alerts them to the fact that there is a problem.
  • the fuse box or circuit breaker unit can be contained in a fire-resistant housing. This will give a degree of resistance, generally measured in a time period such as, for example, two hours.
  • United States Patent US-A-4,706, 073 describes a circuit breaker which incorporates an alarm system.
  • This alarm system includes sensors for sensing a change of light, sound, vibration, temperature, or ionisation level, which is produced by a thermo-electric or magnetic circuit breaker when sensing an overload condition. More particularly, the sensors detect noise or vibration produced by movement of the toggle switch of the circuit breaker.
  • a separate sensor is provided for each circuit breaker in the unit, and in this way is able to detect which of the individual circuit breakers has tripped and provide an alarm indication accordingly.
  • the sensors are on the door of the circuit breaker unit. Amongst other things they can be sensitive to the temperature level or ionisation level which is present during an overload condition.
  • United Kingdom Patent Application GB-A-2073974 describes an industrial circuit interrupter for automatically analysing the electrical conditions in a circuit being protected, which has a circuit breaker mechanism the contracts of which are separated under the control of a micro-computer.
  • a bimetallic switch is mounted on the internal conductors of the circuit breaker and releases the circuit breaker when the conductors overheat. The bimetallic switch is also connected to the microcomputer to activate an alarm.
  • United States Patent US-A-4208689 describes another circuit breaker which has a thermal tripping mechanism to trip the circuit breaker if the load conductors become overheated due to causes such as poor electrical connection to the load. For example the circuit breaker is tripped if the load bus bar temperature reaches 130°C.
  • the circuitry within the circuit breaker is complex and thus expensive.
  • the present inventor has recognised that the inherent safety of an electrical power distribution system for a building, particularly domestic accommodation, would be much improved by the inclusion of an ambient heat sensor in the region of the power distribution unit, such as to sense a temperature increase caused by heating within the unit such as might result from a poor electrical connection, the output of the sensor being operative automatically to disconnect electrical power from the unit or the relevant part thereof.
  • the heat sensor is preferably arranged to trigger at a temperature significantly higher than the normal likely summer ambient temperature, but below that necessary, for example to melt a fuse. The sensor can sense the presence of heat before sufficient heat is generated to cause combustion, and thus actually prevent, as opposed to merely identify or alert, a fire.
  • the unit includes a residual current device as the cut-out.
  • a residual current device as the cut-out.
  • Such devices are already incorporated in some commercially-available distribution boxes, and thus there is a minimum of additional equipment required.
  • the heat sensor can take many forms, and can be coupled to the residual current device in different ways.
  • the connection between the heat sensor and the cut-out may be one that does not require an electrical supply, and it may, in particular, be a mechanical connection.
  • the heat sensor may be constituted by a pivotally-mounted thermometer which changes position when a predetermined temperature rise causes the mercury to move and to change the centre of gravity sufficiently to cause the thermometer to pivo .
  • a piece of spring wire can be connected between the thermometer and the residual current device to operate the latter in the case of such movement.
  • connection can be electrical. If electrical power is required it can be supplied from the mains supply, which will of course be live if it is in danger of causing a fire. It is preferred not to use a battery, as this can run down, but this would be a less- desirable alternative possibility.
  • the residual current device used in the unit is a known type of device which detects an imbalance in the current through the live and neutral conductors, indicating leakage to earth (ground) , and when such leakage exceeds a predetermined value, operates as a cut ⁇ out to disconnect the supply.
  • the heat sensor can be connected to the residual current device, so that in the presence of excess . heat the residual current device is caused to trigger and disconnect the supply, even though the current through it may otherwise be balanced as between the live and neutral conductors, and even though there is no overload such as would trigger the normal overload protection.
  • Fi ⁇ ure 1 is a front view of an electric power distribution unit for use in a domestic installation, with the front cover removed;
  • Figure 2 is a side section through the unit of
  • Figures 3A and 3B show in schematic form two possible types of heat sensor and their connection to a cut-out; and Figure 4 is an electrical circuit diagram for the unit of Figure 1.
  • FIG. 1 a circuit breaker unit 10 which has a generally rectangular casing 12, the front cover of which is removed and is thus not shown in Figure 1.
  • the casing forms a substantially closed housing when mounted on the wall of a building.
  • the unit contains an ON/OFF switch 14 to which the supply is connected, a residual current device (RCD) 16 which receives the live and neutral output of the switch 14, and a bank 18 of miniature circuit breakers connected to receive the live output of the RCD 16. Residual current devices are well- known and readily available. Individual circuits are then connected to the respective circuit breakers.
  • RCD residual current device
  • the respective circuit breaker triggers, and a button 20 on the circuit breaker is automatically pushed outwardly at the same time as the circuit is broken. After the fault has been corrected the circuit breaker can be re-set by manual depression of the button. In the event of an earth (ground) fault, the RCD will detect a current imbalance and will trigger, cutting off the supply to all the circuits. After the earth fault has been corrected the RCD can be re-set.
  • the unit further includes within the housing 10, and preferably placed immediately above the bank of circuit breakers 18, a thermal sensor 22, illustrated purely diagrammatically in Figures 1 and 2 which is connected to the RCD 16.
  • the thermal sensor 22 is located so that it is in the path of convection of any heat generated in the bank of circuit breakers. In the event of one of the circuit breakers overheating, the thermal sensor will trigger, and cause the RCD 16 to trigger and disconnect the supply. In this way, any danger of fire is averted.
  • FIG 2 illustrates the location of the sensor above the circuit breakers 18.
  • the manner in which the heat sensor 22 is connected to the RCD 16 is not shown in Figures 1 and 2, as it can take many forms.
  • One possibility is shown in Figure 3A.
  • a mercury thermometer 30 is mounted on a pivot 32, so that when cold, with the mercury fully within the bulb 34 of the thermometer, the thermometer tends to pivot clockwise as seen in Figure 3A, with its top end resting against a stop 36. When it heats up the mercury moves up the thermometer and its centre of gravity also moves to the left. When a dangerous temperature rise is sensed, the mercury will have moved for enough to cause the thermometer to pivot anti-clockwise.
  • This movement is conveyed to the RCD 16 by a light wire 38 coupling the thermometer and the RCD. The movement mechanically moves the trigger element in the RCD.
  • connection is an electrical connection.
  • a bimetallic strip 40 is used as the heat sensor. This is connected at one end to the RCD 16 by an electrical conductor 42. The other end of the bimetallic strip closes against a contact 44 when the temperature rises to a preset value.
  • This contact 44 is connected to the RCD by a conductor 46.
  • the connection 40,44 is such as to draw a small current, e.g. through a resistor, from the live conductor to earth (ground) . Current flowing through contact 44 thus causes an imbalance in the live and neutral currents through the RCD, thereby causing it to trigger and disconnect the supply.
  • Figure 4 shows the electrical connections, which are omitted from Figure 1 in the interests of clarity.
  • the mains supply illustrated at 24, is applied to the switch 14 and then to the RCD 16.
  • the live output of the RCD is applied to a live bus 26 which distributes it to the circuit breaker bank 18.
  • the neutral output of the RCD 16 is applied to a bus or distribution point 27.
  • Individual circuits are then connected to the output of one of the circuit breakers, and to the neutral bus or distribution point 27.
  • the heat sensor 22 located adjacent to the circuit breaker bank 18 causes the RCD to trigger, in the same way that it would if the current in the live conductor and the current in the neutral conductor were not equal due to a circuit fault.
  • the heat sensor could be located within the bank of circuit breakers 18.
  • a separate heat sensor could be located in or adjacent to each of the individual miniature circuit breakers, each causing the RCD 16 to trigger.
  • the sensor is set to trigger at a temperature above normal summer ambient temperatures, but below that at which combustion can occur. In this way any build up of heat preliminary to an actual fire occurring will be detected and trigger the unit before a dangerous situation arises. While the precise temperature at which the thermal sensor would need to operate will be a matter of empirical determination, it is believed that a temperature in the range 50°C to 80°C is likely to be appropriate.
  • the principles of the embodiment described can be incorporated in other electrical power distribution units, such as a conventional fuse box, rather than a circuit breaker.
  • the sort of heat that will cause a fuse to fail is usually less than that which would cause a significant danger of fire, and appropriate adjustment of the thermal sensor should ensure that it will not normally operate in the event of a fuse blowing.
  • the principles disclosed can be used in a larger installation, such as with a three-phase supply.

Landscapes

  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Distribution Board (AREA)
  • Emergency Protection Circuit Devices (AREA)
  • Remote Monitoring And Control Of Power-Distribution Networks (AREA)

Abstract

Un ensemble (10) formant coupe-circuit électrique comporte un interrupteur-séparateur (14), un interrupteur de protection contre les courants de court-circuit (16) pour détecter un déséquilibre de courant, et des coupe-circuits (18) pour détecter une surcharge de courant. Un capteur thermique (22) est fixé dans le boîtier (12) de l'ensemble. Ce capteur déclenche l'interrupteur de protection contre les court-circuits (16) pour déconnecter automatiquement l'alimentation lorsque la température dans cet ensemble augmente de manière significative et excède la température ambiante, comme cela peut se produire en cas de surchauffe due à une mauvaise connexion dans le coupe-circuit.
EP96914315A 1995-05-19 1996-05-20 Reseau de distribution d'energie electrique pour batiments Withdrawn EP0834209A1 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GB9510173 1995-05-19
GBGB9510173.9A GB9510173D0 (en) 1995-05-19 1995-05-19 Safety device for electric power distribution systems for buildings
PCT/GB1996/001201 WO1996037025A1 (fr) 1995-05-19 1996-05-20 Reseau de distribution d'energie electrique pour batiments

Publications (1)

Publication Number Publication Date
EP0834209A1 true EP0834209A1 (fr) 1998-04-08

Family

ID=10774735

Family Applications (1)

Application Number Title Priority Date Filing Date
EP96914315A Withdrawn EP0834209A1 (fr) 1995-05-19 1996-05-20 Reseau de distribution d'energie electrique pour batiments

Country Status (6)

Country Link
EP (1) EP0834209A1 (fr)
AU (1) AU5771996A (fr)
CA (1) CA2225753A1 (fr)
EA (1) EA199700400A1 (fr)
GB (1) GB9510173D0 (fr)
WO (1) WO1996037025A1 (fr)

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1889346A1 (fr) * 2005-05-25 2008-02-20 Callsmart UK Limited Protection thermique pour installations et raccords electriques
US8103387B2 (en) 2008-04-28 2012-01-24 Lockheed Martin Corporation Adaptive power system
GB2471869B (en) 2009-07-15 2012-04-25 Vishay Resistors Belgium Bvba Thermal switch
US8344724B2 (en) 2009-11-06 2013-01-01 Massachusetts Institute Of Technology Non-intrusive monitoring of power and other parameters
GB201211709D0 (en) * 2012-07-02 2012-08-15 Indumission Ltd Protecting electrical distribution equipment against overheating
NL2018374B1 (nl) * 2017-02-14 2018-09-04 Abb Schweiz Ag Groepenkast met bewakingsinrichting
CN107644504B (zh) * 2017-09-13 2019-09-20 河南省三禾电气有限公司 电气事故监控系统及方法

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4208689A (en) * 1978-03-15 1980-06-17 Square D Company Circuit breaker having an electronic fault sensing and trip initiating unit
IN161314B (fr) * 1984-09-25 1987-11-07 Oscar Vila Masot
JP2611481B2 (ja) * 1990-03-08 1997-05-21 日本電気株式会社 電子装置の温度異常検出回路

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9637025A1 *

Also Published As

Publication number Publication date
GB9510173D0 (en) 1995-07-12
CA2225753A1 (fr) 1996-11-21
WO1996037025A1 (fr) 1996-11-21
AU5771996A (en) 1996-11-29
EA199700400A1 (ru) 1998-08-27

Similar Documents

Publication Publication Date Title
US4858054A (en) Protective circuits and devices for the prevention of fires
US7312963B1 (en) Protective device with tamper resistant shutters
US5818671A (en) Circuit breaker with arcing fault detection module
US6969801B2 (en) Shuttered receptacle for a protective device
US7751162B1 (en) Protective device with miswire protection
US20030151478A1 (en) Protection device with lockout test
US8159803B2 (en) Heat actuated interrupter receptacle
US6744254B2 (en) Breaker failure annunciator system
CA2308977A1 (fr) Systeme de protection pour dispositifs branches a une source d'alimentation electrique a courant alternatif
CA2645469C (fr) Disjoncteur de fuite de terre avec protection contre les erreurs de cablage, equipe d'une prise unitaire, et conducteurs de charge apres installation appropriee
EP1068601B1 (fr) Procede d'interruption de l'alimentation electrique en cas de danger, et systeme de securite associe
KR100835371B1 (ko) 전달열 감시 기능을 구비한 배선용 차단기
WO1996037025A1 (fr) Reseau de distribution d'energie electrique pour batiments
US3766437A (en) Safety interlock system for microwave ovens
KR20070079129A (ko) 전달열 차단 기능을 구비한 배선용 차단기
US6466424B1 (en) Circuit protective device with temperature sensing
US4001804A (en) Ground fault protection for electrical power distribution systems
JPH079782B2 (ja) 過熱防止装置付回路遮断器
EP0661790B2 (fr) circuit de protection de courant excessif
FI117360B (fi) Menetelmä ja järjestelmä, jolla suojataan sarjavuodolta
EP3411929B1 (fr) Prise de courant de sécurité
US20060146465A1 (en) Protective switch
GB2477737A (en) Fire prevention system triggering a residual current device
USRE28822E (en) Safety interlock system for microwave ovens
CZ75595A3 (en) Thermal protection against overload for switches

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19971209

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

AX Request for extension of the european patent

Free format text: AL PAYMENT 971209;LT PAYMENT 971209;LV PAYMENT 971209;SI PAYMENT 971209

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19991201