GB2214734A - Residual current circuit breaker - Google Patents

Residual current circuit breaker Download PDF

Info

Publication number
GB2214734A
GB2214734A GB8801986A GB8801986A GB2214734A GB 2214734 A GB2214734 A GB 2214734A GB 8801986 A GB8801986 A GB 8801986A GB 8801986 A GB8801986 A GB 8801986A GB 2214734 A GB2214734 A GB 2214734A
Authority
GB
United Kingdom
Prior art keywords
switch means
switch
relay
circuit breaker
residual current
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
GB8801986A
Other versions
GB2214734B (en
GB8801986D0 (en
Inventor
Douglas Sydney Knights
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.)
B & R Electrical Prod Ltd
Original Assignee
B & R Electrical Prod 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 B & R Electrical Prod Ltd filed Critical B & R Electrical Prod Ltd
Priority to GB8801986A priority Critical patent/GB2214734B/en
Publication of GB8801986D0 publication Critical patent/GB8801986D0/en
Publication of GB2214734A publication Critical patent/GB2214734A/en
Application granted granted Critical
Publication of GB2214734B publication Critical patent/GB2214734B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R13/00—Details of coupling devices of the kinds covered by groups H01R12/70 or H01R24/00 - H01R33/00
    • H01R13/66—Structural association with built-in electrical component
    • H01R13/70—Structural association with built-in electrical component with built-in switch
    • H01R13/713—Structural association with built-in electrical component with built-in switch the switch being a safety switch
    • H01R13/7135—Structural association with built-in electrical component with built-in switch the switch being a safety switch with ground fault protector
    • 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
    • H02H3/33—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 using summation current transformers
    • 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
    • H02H3/33—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 using summation current transformers
    • H02H3/334—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 using summation current transformers with means to produce an artificial unbalance for other protection or monitoring reasons or remote control
    • H02H3/335—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 using summation current transformers with means to produce an artificial unbalance for other protection or monitoring reasons or remote control the main function being self testing of the device
    • 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
    • H02H3/33—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 using summation current transformers
    • H02H3/338—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 using summation current transformers also responsive to wiring error, e.g. loss of neutral, break

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Breakers (AREA)

Abstract

A residual current circuit breaker apparatus includes a relay RLI with contacts RLI/1, RLI/2 closing on insertion of the load's electrical connector E, and the apparatus being tested, with the relay contacts opening, on removal of the electrical connector. The electrical connector E engages the rocker contact member of a switch SW to actuate the relay electronically. On insertion of the electrical connector E, operation of the switch SW causes a voltage to be delivered across the relay coil RLI which is sufficient to close the relay contacts. Reverse operation of the switch SW activates test circuitry R3, W4 to reduce the voltage across the relay coil causing the relay contacts to open. A coil W3 responds to loss of balance in the supply and to the test coil W4 by firing SCRI to de-energise relay coil RLI. Coil W4 is also responsive to live-neutral reversal. <IMAGE>

Description

Residual Current Circuit Breaker The present invention relates to residual current circuit breakers.
Residual current circuit breakers (RCCBs) are known which function such that, on connection of any electrical equipment to a mains supply via an RCCB any dangerous out of balance condition between the current flowing through the live wire and the current flowing through the neutral wire may be detected and the mains supply cut off in response thereto, to prevent electrocution and/or damage to electrical equipment, for example.
It is known to provide RCCB's with an external user operable switch (such as, for example, a push button) which it is necessary for the user himself to actuate in order to reset the RCCB after it has tripped in response to any out of balance condition.
The present invention provides residual current circuit breaker apparatus, comprising an electrical supply socket arranged to receive an electrical connector, for connecting a load to an electrical supply, a first switch means connected in the electrical supply path, detection circuitry for detecting an out of balance condition in the electrical supply to the load and, responsive thereto, for operating the first switch means to isolate the load from the supply, and a second switch means arranged to be actuated by direct contact with the electrical connector to initially set the apparatus for operation, the second switch means being connected to circuitry which, on actuation of the second switch means, causes operation of the first switch means to connect the supply to the load.
The apparatus has the advantage that there is no necessity for the provision of an external reset button to be operated by the user, as the circuit is automatically reset on connection of the electrical connector in the socket.
Further the second switch sets the apparatus via associated circuitry acting to operate the first switch.
Because the second switch does not directly mechanically operate the first switch there is no danger that any possible jamming of the second switch would prevent normal circuit breaking operation of the first switch.
The socket may be arranged to receive a standard mains supply three pin plug, for example, the earth pin of which is arranged to actuate the second switch means.
A testing facility is also preferably incorporated.
In a preferred form this is realised by testing circuitry which is responsive to the electrical connector being removed from the socket to cause the production of a signal which is arranged to effect the detection circuitry in the same way as an out of balance condition of the electrical supply. If the detection circuitry is functioning correctly the first switch will be operated to disconnect the electrical supply, as it would if there were an out of balance condition. Correct operation of the circuitry is indicated by visible means. The electrical supply remains disconnected until an electrical connector is inserted in the socket, thereby resetting the apparatus.
In a preferred embodiment the first switch means is a relay switch, and the circuitry associated with the second switch means is preferably arranged to provide a voltage large enough to actuate a relay having a contact gap of 3mm or more. This has the advantage of meeting British Standards as far as relay contact gap is concerned.
Actuation of the same second switch means is preferably used to initiate both setting and testing of the apparatus.
The apparatus then has the advantage that both setting and testing of the RCCB are carried out without the need for any external operation by the user apart from the insertion and removal of the electrical connector to the load.
Features and advantages of the present invention will become clear from the following description of an embodiment thereof, by way of example only, with reference to the accompanying drawings, in which, Figure 1 is a circuit diagram of electrical circuitry utilised in accordance with an embodiment of the present invention; Figure 2 is a side view cross-section of RCCB apparatus in accordance with an embodiment of the present invention, and Figure 3 is a side view of a first switch means utilised in the embodiment of Figure 2.
With reference to Figure 1, RCCB circuitry for use with a standard three lead household supply includes a relay switch RL1 having contacts RLl/l, RL1/2 in the live L and neutral N lines of the electricity supply path. The switch RL1 controls the electricity supply to the OUTPUT, where a load may be connected. When electricity is being provided to the OUTPUT, detection circuitry comprising toroid T, windings W1, W2, switch SCR1, resistor R2 and capacitor C2, respond to any out of balance condition in the electricity supply to cause release of switch contacts RLl/l and RL1/2, so as to isolate the OUTPUT from the electricity supply.
A further switch SW, which is actuated by the earth pin E of a standard three pin plug, initially sets the circuit for operation, by causing associated circuitry Cl,Rl,Dl to activate switch RL1 to close the contacts RLl/l, RL1/2. Testing circuitry R3, W4, is actuated on removal of the earth pin E and consequent release of the switch SW.
In more detail, from Figure 1 it can be seen that the relay RL1 is energised by transferring a charged capacitor C1 to the relay RL1 by the switch SW. The capacitior C1 is charged by the circuit D1 and R1 to a relatively high voltage (for example 250-300vdc) which is sufficient to energise the relay RL1 with a 3mm+ contact gap, and does not require relay RL1 to be particularly sensitive. When the switch SW has transferred from the N/C contact to the N/O contact, the circuit comprising D1, R1, C1 and RL1 reduces the voltage across the coil of RL1 to a-value sufficient to ensure that it remains energised (for example 40-50vdc).
Any out of balance condition in the electricity supply to the OUTPUT, due to, for example, an earth leakage feult condition, will cause the toroid T to produce an output at winding W3, which will be amplified by AMP and will cause SCR1 to fire. This will cause a reduction in the voltage across the coil of relay RL1 to a value determined by the coil of RL1 in parallel with the resistor R2, and such that the relay RL1 releases, isolating the load from the electricity supply.
Figure 3 shows a view of the relay RL1 from which it can be seen that this is a skeleton type of relay, the moving contact moulding of which also performs the function of a mechanical indicator (indicating whether the relay contacts are closed or open), thus the requirements of British Standards for 3mm contact gap and mechanical indication can be met. The indicator is provided by flag F, which changes position as the relay RL1 is actuated.
Figure 2 shows a cross-section through the body of an RCCB adaptor in accordance with an embodiment of the present invention. Switch SW comprises two fixed contact members, shown in the Figure as N/C and N/O. The common moving contact member C is provided with an insulated actuator I, which is contacted by the earth pin E of a standard three pin plug to move the contact member C from the N/C contact to the N/O contact. This sets the relay RL1 into operative condition as described above in relation to Figure 1. The three pin plug is received in the socket S in the RCCB adaptor.
Switch SW is so designed that the moving contact member C makes contact with the fixed normally open contact, N/O, energising relay RLl,before the live and neutral pins of the plug make contact with their corresponding mating sockets, preventing closure onto a load or a short circuit by the contacts RLl/l and RL1/2 of relay RL1.
The RCCB adaptor further comprises a body B, which houses therein a circuit board PCB having operating circuitry mounted thereon. Connectors A are provided from the socket S and a plug P (for plugging into the mains supply) to the components on the circuit board PCB. A window W is provided in the body B to allow the user to view the flag indicator F of the relay RL1. A standard shutter SH is provided for the socket S.
Referring both to Figures 1 and 2, on removal of the three pin plug testing circuitry is activated to test whether the out of balance detection circuitry is functioning correctly. It can be seen that when the three pin plug is inserted, the relay RL1 closes and holds over its own coil. When the three pin plug is removed capacitor C1 remains connected to the coil of RL1 by contact RLl,l, and when switch SW closes to the normally closed contact N/C a testing circuit, comprising resistor R3 and coil W4, is made. The test circuit causes the toroid T to produce an output at coil W3.If the detection circuitry is functioning correctly SCR1 will be fired to cause opening of the relay contacts RLl/l, RL1/2. Correct functioning of the circuit is indicated by the flag F moving out of the window W.
It should be noted that winding W4 can also be used to detect the reversal of live and neutral in a socket by means of resistor R4 connected to earth and W4.
If required, indication of live and neutral reversal can be given by the addition of resistor R1 and neon N.
Lost neutral is detected by virtue of the fact that being a relay RCCB, RL1 releases when the neutral is missing.
When the appliance plug is inserted into the RCCB adaptor, the earth pin isolates the test circuit and energises relay RL1 as previously described.
From the above it can be seen that the necessity for test and reset buttons has been eliminated by reason of the appliance plug earth pin being used to directly actuate a switch, electrically operating a relay and completing a test circuit when withdrawn.
The present invention is suitable for use with such electrical devices as electric lawnmovers, for example.

Claims (7)

CLAIMS:
1. A residual current circuit breaker apparatus, comprising: an electrical supply socket arranged to receive an electric connector, for connecting a load to an electrical supply; a first switch means connected in the electrical supply path; detection means, including a first coil, for detecting an out of balance condition in the electrical supply to the load and, responsive thereto, for operating the first switch means to isolate the load from the supply; a second switch means arranged to be actuated by direct contact with the electrical connector to initially set the apparatus for operation, said second switch means being connected to actuation means which, on actuation of said second switch means, causes operation of said first switch means to connect said load to said electrical supply; and a test means, including a second coil magnetically linked to said first coil, for testing said detection means on reverse actuation of said second switch means.
2. The residual current circuit breaker as set forth in claim 1, wherein: said first switch means comprises a relay; and said actuation means provides a voltage sufficiently large to actuate a relay having a contact gap of 3mm or greater.
3. The residual current circuit breaker as set forth in claim 1, wherein: said second switch means comprises a rocker contact member having an insulating portion at its free end which, while making contact with said electrical connector during insertion of said electrical connector,causes said rocker contact member to switch contact from a first pole to a second pole of said second switch means.
4. The residual current circuit breaker as set forth in claim 3, wherein: removal of said electrical connector causes said rocker contact member to switch contact from said second pole to said first pole of said second switch means.
5. The residual current circuit breaker as set forth in claims 3 or 4, wherein: connection of said rocker contact member to said first pole of said second switch means actuates said test means to produce an out-of-balance condition.
6. The residual current circuit breaker as set forth in claim 5 wherein: detection of said out-of-balance condition by said detection means causes actuation of said first switch means to its open-circuit condition.
7. The residual current circuit breaker substantially as hereinbefore described with reference to the accompanying drawings.
GB8801986A 1988-01-29 1988-01-29 Residual current circuit breaker Expired - Fee Related GB2214734B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB8801986A GB2214734B (en) 1988-01-29 1988-01-29 Residual current circuit breaker

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB8801986A GB2214734B (en) 1988-01-29 1988-01-29 Residual current circuit breaker

Publications (3)

Publication Number Publication Date
GB8801986D0 GB8801986D0 (en) 1988-02-24
GB2214734A true GB2214734A (en) 1989-09-06
GB2214734B GB2214734B (en) 1992-06-03

Family

ID=10630727

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8801986A Expired - Fee Related GB2214734B (en) 1988-01-29 1988-01-29 Residual current circuit breaker

Country Status (1)

Country Link
GB (1) GB2214734B (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2238921A (en) * 1989-12-07 1991-06-12 Wellong Trading Ltd Ground fault circuit interrupter
GB2251992A (en) * 1991-01-17 1992-07-22 Shakira Ltd Missing earth or neutral mains monitor
WO2002035661A1 (en) * 2000-10-24 2002-05-02 Mark Macdonald Electrical power outlet

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2238921A (en) * 1989-12-07 1991-06-12 Wellong Trading Ltd Ground fault circuit interrupter
GB2251992A (en) * 1991-01-17 1992-07-22 Shakira Ltd Missing earth or neutral mains monitor
GB2251992B (en) * 1991-01-17 1994-04-06 Shakira Ltd A C mains monitoring circuit
WO2002035661A1 (en) * 2000-10-24 2002-05-02 Mark Macdonald Electrical power outlet

Also Published As

Publication number Publication date
GB2214734B (en) 1992-06-03
GB8801986D0 (en) 1988-02-24

Similar Documents

Publication Publication Date Title
US7317600B2 (en) Circuit interrupting device with automatic end of life test
AU743501B2 (en) Circuit interrupter with test actuator for ground fault and arc fault test mechanisms
CN202550296U (en) Electrical wiring device used for power distribution system
US7009473B2 (en) Ground-fault circuit interrupter with reverse wiring protection
US5363269A (en) GFCI receptacle
US7701680B2 (en) Ground-fault circuit interrupter
CA2170695C (en) Reverse wiring indicator for gfci receptacles
US4995017A (en) Safety power receptacle
US20080094765A1 (en) Circuit interrupting device with automatic end of life test
US7136267B2 (en) Electrical ground protection device and method
US8830015B2 (en) Compact latching mechanism for switched electrical device
JPS6388729A (en) Multi-polar ground fault protector/breaker
CN101479904A (en) A time alert device for use together with an earth leakage protection device
GB2205700A (en) Modular electric circuit breaker apparatus
CN105164782A (en) Self-testing auto monitor ground fault circuit interrupter (GFCI) with power denial
TW200300561A (en) Control and protection module of a switch device
KR102066852B1 (en) Protection and distribution panal with inspection switches
US4725772A (en) Electrical circuit tester selectively responsive to either presence or absence of AC power
CN101609969B (en) A control device for an automatic reset apparatus
CA1311827C (en) Electrical safety device
GB2214734A (en) Residual current circuit breaker
CN101246795B (en) Ground fault line breaker
CN101106044B (en) Shunt release capable of detecting working state of circuit breaker
GB2231215A (en) Residual current circuit breaker
US5631565A (en) Device for measuring residual voltage and energy in a piece of equipment

Legal Events

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