CA1127747A - Wireless emergency power interrupting system - Google Patents
Wireless emergency power interrupting systemInfo
- Publication number
- CA1127747A CA1127747A CA313,708A CA313708A CA1127747A CA 1127747 A CA1127747 A CA 1127747A CA 313708 A CA313708 A CA 313708A CA 1127747 A CA1127747 A CA 1127747A
- Authority
- CA
- Canada
- Prior art keywords
- circuit
- ground fault
- ground
- conductor
- switch
- 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
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
- H02H3/33—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
- 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
- H01H83/02—Protective switches, e.g. circuit-breaking switches, or protective relays operated by abnormal electrical conditions otherwise than solely by excess current operated by earth fault currents
- H01H83/04—Protective switches, e.g. circuit-breaking switches, or protective relays operated by abnormal electrical conditions otherwise than solely by excess current operated by earth fault currents with testing means for indicating the ability of the switch or relay to function properly
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Emergency Protection Circuit Devices (AREA)
- Breakers (AREA)
- Details Of Connecting Devices For Male And Female Coupling (AREA)
Abstract
47,362 WIRELESS EMERGENCY POWER
INTERRUPTING SYSTEM
ABSTRACT OF THE DISCLOSURE
A system for deenergizing an electrical power dis-tribution circuit under emergency conditions. The system comprises a three-wire power circuit including a line con-ductor, a neutral conductor, and a ground conductor, the circuit being protected by a ground fault circuit breaker operable upon detection of ground fault current in the circuit to disconnect the circuit from the source of electrical power. A plurality of receptacles are included in the circuit downstream from the ground fault circuit breaker to receive connecting plugs of electrical apparatus to be powered from the circuit. A removable plug adapted for insertion into any of the receptacles includes at least three pins, each pin being connected to one of the conductors when the plug is inserted into a receptacle. The series combination of a resistor and a momentary contact pushbutton switch is connected between the pins which come in electrical contact with the line conductor and the ground conductor.
Actuation of the pushbutton switch when the plug is inserted into any of the receptacles produces a flow of current from the line conductor to the ground conductor, thereby actuat-ing the ground fault circuit breaker and disconnecting the circuit downstream from the breaker from a source of elec-trical power.
INTERRUPTING SYSTEM
ABSTRACT OF THE DISCLOSURE
A system for deenergizing an electrical power dis-tribution circuit under emergency conditions. The system comprises a three-wire power circuit including a line con-ductor, a neutral conductor, and a ground conductor, the circuit being protected by a ground fault circuit breaker operable upon detection of ground fault current in the circuit to disconnect the circuit from the source of electrical power. A plurality of receptacles are included in the circuit downstream from the ground fault circuit breaker to receive connecting plugs of electrical apparatus to be powered from the circuit. A removable plug adapted for insertion into any of the receptacles includes at least three pins, each pin being connected to one of the conductors when the plug is inserted into a receptacle. The series combination of a resistor and a momentary contact pushbutton switch is connected between the pins which come in electrical contact with the line conductor and the ground conductor.
Actuation of the pushbutton switch when the plug is inserted into any of the receptacles produces a flow of current from the line conductor to the ground conductor, thereby actuat-ing the ground fault circuit breaker and disconnecting the circuit downstream from the breaker from a source of elec-trical power.
Description
BACKGROUND OF TH~ IN~ENTION
Field o~ the Invention:
The invention relates to electrical apparatus and, more particularly, to a system for disconnecting an electrical power distribution circuit from a source of electrical power ''' . ~ ,.
1127q47 47,362 durlng e~er~ency cQndltions~
Description of the Prior Art:
Emergency electr~cal po~er interrupting "panic buttons" are ~idely used in laboratories, shops, factories, and commercial establishments. Such systems normally con-sist of large easily seen red pushbutton s~itches located in readilyaccessible places to provide for rapid interruption of electrical power should an emergenc~ occur. In prior art systems, the panic button operates a normally open push-button switch which is used to energize the trip coil of a circuit breaker protecting the power distrlbution circuit.
Thus~ separate wiring must be provided between the clrcuit breaker and each location wherein it is desired to place a panic button. The cost and complexity of this additional wlring has often meant that the number of panic buttons installed has been less than would be desirable. In other situations, this cost and complexity has completely ruled out the installation of such an emergency power ~nterruption system.
In most industrial and commercial installations, and in many re~idential installations, National Electric Code requirements call for the inclusion of ground fault protective capability in addition to overload current pro-tection. Such ground fault protectlve equipment is normally designed to deenergize the associated electrical power ~ gr~nd ~u 1~
distribution network upon detection of~current levels much less than the overload current trip leYels. For example, many residential ground fault circuit breakers are deslgned to trlp upon detection of 5 milliamperes of ground fault current.
, -2-47,362 It is desirable to provide an e~ergency power interruption system which does not re~uire additional wlring other than the power wiring and which utilizes the sensitive detection capability of the ground fault current protection capability already existing in man~ installations.
SUMMARY OF THE INVENTION
In accordance with a preferred embodiment of the present invention, there is provided an emergency power interruption system for use on an electrical power line.
The system includes a ground fault circuit breaker adapted to deenergize the circuit being protected upon detection of ground fault current above a predetermined level. The system further comprises means located downstream from the ground fault circuit breaker for deliberately initiating ground fault current in the electrical power line which is above the ground fault tripping current level of the ground fault circuit breaker.
In a preferred embodiment of the invention, the electrical power circuit includes a line conductor, a neutral conductor, and a ground conductor, and a plurality of recep-tacles adapted to receive cooperating power plugs attached B to electrical apparatus to be powered from the circuit. The ground fault current initiating means comprises a plug ~ n~l adapted for :Insertlon into ~ff~ of the receptacles, and having a pushbutton switch connected between the pins of the plug which come in contact with the line conductor and the ground conductor when the plug is inserted into a receptacle.
By actuating the pushbutton switch, ground fault current is initiated to caus~i the ground fault circuit interrupter to trlp and lsolate the circuit from the source of electrical 30~ power.
47,362 B~ D~SCRIPTIO~ OF TH~ D~A~ING
The invention may ~e more readily understood b~
reference to the ~ollowing specification and to the drawin~
which is a diagram, partially schematic and partially pic-torial, of an electrical power circuit incorporating the present invention.
DESCRIPTION OF TH~ PREFER~ED EMBODI~ENT
Referring now to the dr~wing, a three-wire electri- -cal power circuit 12 supplied by a power source (not shown) upstream to the left comprises a line (or phase) conductor L, a neutral conductor N, and a ground conductor G. Con~
nected to the circuit 12 are a plurality of three-wire receptacles 14, only one of ~hich is shown in the drawing.
Cooperating plugs from electrical apparatus are inserted into the receptacles 14, thereby providing power to the apparatus. As can be seen, the receptacle 14 includes a ; terminal 22 connected to the line conductor L, a terminal 24 connected to the ground conductor G, and a terminal 26 connected to the neutral conductor N.
A ground fault circuit interrupter 16 is inserted ln the circuit 12 between the power source and the first of the receptacles 14. The ground ~ault circuit interrupter 16 B co~ fs /~
includes ~ separable oontaot in series with the line con-ductor L of the circuit 12. In a manner well known in the art, current flow from line conductor L to ground is sensed, and upon occurrence of ground fault current abo~e a predeter-mined level, the contacts 18 are separated, thereby deenergi-zing that portion of the circuit 12 downstream from the circuit breaker 16.
The level of ground fault current which will cause 1127 7~7 ~7,362 the breaker 16 to trip depends upon the particular applica-tion. For examplet a "people-protecting" ground fault circuit breaker designed to prevent serious injury to a person accidentally coming into simultane-ous contact with the conductor L and ground, is designed to trip at a level of approximately 5 milliamperes. This is, of course, much less than the overcurrent trip level of the circuit breaker 16, a function designed merely to protect the conductors themselves from damage due to overload current levels in the range of several amperes or higher.
In the present invention, means are provided for deliberately initiating a flow of current from the line con-ductor L to ground. When such current flow reaches the ground fault tripping current level of the circuit breaker 16~ the breaker 16 will trip, thereby deenergizing the circuit. In a preferred embodiment of the invention a plug 20, externally identical to the pIugs of the power cords of electrical apparatus being supplied by the circuit 12, is modified to include a pushbutton switch 34 having contacts 36. The plug 20 a~so includes pins 2~, 30 and 32 cooperating with corresponding terminals 22, 26, and 24 to make electri-cal contact with the conductors L, N and G, respectively.
The contacts 36 of the switch 34 are connected in series with a resistor 3~, and the resulting series combination connected between the pins 2~ and 32 of the plug 20. As can be seen, actuation of the switch 34 will thus provide an electrical connection between the pin 2~ and the pin 32.
When the plug 20 iæ inserted into the receptacle 14, actua-tion of the ~witch 34 allows current to flow from the con-ductor L through the terminal 22, the pin 2~, the resistor - ' ' ~17,362 B 38, the contacts 36, the Pin ~, and the terminal 24 to the ground conductor ~. The size of the resistQr 38 is selected according to the ~oltage upon the circuit 12 to p~ovide a flow of ground current greater than the ground fault trip-ping current level of the circuit bre~ker 16. Thus, when-ever the pushbutton switch 34 is actuated, the circuit breaker 16 will trip, there~y deenergizing the circuit 12 and isolating that portion of the circuit 12 downstream from the circuit breaker 16 from contact with the electrical power source. In a typical application on a 115 VAC circuit, the circuit breaker 16 can be set to a ground fault tripping current level of 5 milliamperes, thereby providing protection against serious in~ury should a human being come in simul-taneous contact with the line conductor L and ground. By providing the resistor 38 with a value of 10,000 ohms, a a~r~ n1N~eJ(1 ground current ofA12 milliamperes will be caused to flow when the pushbutton 34 is acutated. This level is ~ar in excess of the level necessary to trip the circuit breaker 16, yet is much below the overcurrent tripping current level which would cause damage to the conductors of the circuit 12.
By selecting a value for the resistor 38 which yields a current under normal voltage conditions far in excess of the ground fault interrupter tripping current level, sufficient margin is provlded to insure that under emergency conditions (during which time the line voltage may drop dramatically) the current through the resistor 38 will still be sufficient to trip the breaker. The disclosed invention could, of course, be used on a multiphase circuit protected by a multiphase ground fault circuit breaker. It ~ -6-47,362 would then only be necessary to provide a flow o~ current ~rom one Or the phases to ground. r~he Gircuit breaker would trip regardless of which phase ~as selected.
The resistor 38 i~s~ cf course, not necessary for the operation of the invention~ Ho~ever, the presence of the resistor limits the level of ground current which will flow, thereby allowing the use of inexpensive low current rating contacts 36. Other impedance means could also be used in place of the resistor 38 to provide this current-limiting function.
By installing the ground current initiating meansin the plug 20, a variety of advantages is obtained. The plug can be placed in any or all of the receptacles 14 upon the circuit 12. The cost of each plug 20 is much lower than the cost of providing prior art emergency power interrupting buttons requiring separate wiring to a circuit breaker trip coil. In addition, if a temporary remote panic button is re-quired, it can be provided in a simple, convenient manner through the use of a standard extension cord plugged into the receptacle 14 and inserting the plug 20 in the other end of the extension cord. The plug 20 can then be moved to wherever emergency power interruption capability is required.
Furthermore, a single plug 20 can be carried by an operator to any deslred :Location having a receptacle 14.
It can be seen, there~ore, that the present invention provides an emergency power interruption system which can be installed at extremely lol~ cost upon existing power circuits having ground rault circuit protection. Furthermore, the present inventi.on provides a highly flexi~le and convenient means Or providing emergency power interruptlon capability at a wide variety of locations.
Field o~ the Invention:
The invention relates to electrical apparatus and, more particularly, to a system for disconnecting an electrical power distribution circuit from a source of electrical power ''' . ~ ,.
1127q47 47,362 durlng e~er~ency cQndltions~
Description of the Prior Art:
Emergency electr~cal po~er interrupting "panic buttons" are ~idely used in laboratories, shops, factories, and commercial establishments. Such systems normally con-sist of large easily seen red pushbutton s~itches located in readilyaccessible places to provide for rapid interruption of electrical power should an emergenc~ occur. In prior art systems, the panic button operates a normally open push-button switch which is used to energize the trip coil of a circuit breaker protecting the power distrlbution circuit.
Thus~ separate wiring must be provided between the clrcuit breaker and each location wherein it is desired to place a panic button. The cost and complexity of this additional wlring has often meant that the number of panic buttons installed has been less than would be desirable. In other situations, this cost and complexity has completely ruled out the installation of such an emergency power ~nterruption system.
In most industrial and commercial installations, and in many re~idential installations, National Electric Code requirements call for the inclusion of ground fault protective capability in addition to overload current pro-tection. Such ground fault protectlve equipment is normally designed to deenergize the associated electrical power ~ gr~nd ~u 1~
distribution network upon detection of~current levels much less than the overload current trip leYels. For example, many residential ground fault circuit breakers are deslgned to trlp upon detection of 5 milliamperes of ground fault current.
, -2-47,362 It is desirable to provide an e~ergency power interruption system which does not re~uire additional wlring other than the power wiring and which utilizes the sensitive detection capability of the ground fault current protection capability already existing in man~ installations.
SUMMARY OF THE INVENTION
In accordance with a preferred embodiment of the present invention, there is provided an emergency power interruption system for use on an electrical power line.
The system includes a ground fault circuit breaker adapted to deenergize the circuit being protected upon detection of ground fault current above a predetermined level. The system further comprises means located downstream from the ground fault circuit breaker for deliberately initiating ground fault current in the electrical power line which is above the ground fault tripping current level of the ground fault circuit breaker.
In a preferred embodiment of the invention, the electrical power circuit includes a line conductor, a neutral conductor, and a ground conductor, and a plurality of recep-tacles adapted to receive cooperating power plugs attached B to electrical apparatus to be powered from the circuit. The ground fault current initiating means comprises a plug ~ n~l adapted for :Insertlon into ~ff~ of the receptacles, and having a pushbutton switch connected between the pins of the plug which come in contact with the line conductor and the ground conductor when the plug is inserted into a receptacle.
By actuating the pushbutton switch, ground fault current is initiated to caus~i the ground fault circuit interrupter to trlp and lsolate the circuit from the source of electrical 30~ power.
47,362 B~ D~SCRIPTIO~ OF TH~ D~A~ING
The invention may ~e more readily understood b~
reference to the ~ollowing specification and to the drawin~
which is a diagram, partially schematic and partially pic-torial, of an electrical power circuit incorporating the present invention.
DESCRIPTION OF TH~ PREFER~ED EMBODI~ENT
Referring now to the dr~wing, a three-wire electri- -cal power circuit 12 supplied by a power source (not shown) upstream to the left comprises a line (or phase) conductor L, a neutral conductor N, and a ground conductor G. Con~
nected to the circuit 12 are a plurality of three-wire receptacles 14, only one of ~hich is shown in the drawing.
Cooperating plugs from electrical apparatus are inserted into the receptacles 14, thereby providing power to the apparatus. As can be seen, the receptacle 14 includes a ; terminal 22 connected to the line conductor L, a terminal 24 connected to the ground conductor G, and a terminal 26 connected to the neutral conductor N.
A ground fault circuit interrupter 16 is inserted ln the circuit 12 between the power source and the first of the receptacles 14. The ground ~ault circuit interrupter 16 B co~ fs /~
includes ~ separable oontaot in series with the line con-ductor L of the circuit 12. In a manner well known in the art, current flow from line conductor L to ground is sensed, and upon occurrence of ground fault current abo~e a predeter-mined level, the contacts 18 are separated, thereby deenergi-zing that portion of the circuit 12 downstream from the circuit breaker 16.
The level of ground fault current which will cause 1127 7~7 ~7,362 the breaker 16 to trip depends upon the particular applica-tion. For examplet a "people-protecting" ground fault circuit breaker designed to prevent serious injury to a person accidentally coming into simultane-ous contact with the conductor L and ground, is designed to trip at a level of approximately 5 milliamperes. This is, of course, much less than the overcurrent trip level of the circuit breaker 16, a function designed merely to protect the conductors themselves from damage due to overload current levels in the range of several amperes or higher.
In the present invention, means are provided for deliberately initiating a flow of current from the line con-ductor L to ground. When such current flow reaches the ground fault tripping current level of the circuit breaker 16~ the breaker 16 will trip, thereby deenergizing the circuit. In a preferred embodiment of the invention a plug 20, externally identical to the pIugs of the power cords of electrical apparatus being supplied by the circuit 12, is modified to include a pushbutton switch 34 having contacts 36. The plug 20 a~so includes pins 2~, 30 and 32 cooperating with corresponding terminals 22, 26, and 24 to make electri-cal contact with the conductors L, N and G, respectively.
The contacts 36 of the switch 34 are connected in series with a resistor 3~, and the resulting series combination connected between the pins 2~ and 32 of the plug 20. As can be seen, actuation of the switch 34 will thus provide an electrical connection between the pin 2~ and the pin 32.
When the plug 20 iæ inserted into the receptacle 14, actua-tion of the ~witch 34 allows current to flow from the con-ductor L through the terminal 22, the pin 2~, the resistor - ' ' ~17,362 B 38, the contacts 36, the Pin ~, and the terminal 24 to the ground conductor ~. The size of the resistQr 38 is selected according to the ~oltage upon the circuit 12 to p~ovide a flow of ground current greater than the ground fault trip-ping current level of the circuit bre~ker 16. Thus, when-ever the pushbutton switch 34 is actuated, the circuit breaker 16 will trip, there~y deenergizing the circuit 12 and isolating that portion of the circuit 12 downstream from the circuit breaker 16 from contact with the electrical power source. In a typical application on a 115 VAC circuit, the circuit breaker 16 can be set to a ground fault tripping current level of 5 milliamperes, thereby providing protection against serious in~ury should a human being come in simul-taneous contact with the line conductor L and ground. By providing the resistor 38 with a value of 10,000 ohms, a a~r~ n1N~eJ(1 ground current ofA12 milliamperes will be caused to flow when the pushbutton 34 is acutated. This level is ~ar in excess of the level necessary to trip the circuit breaker 16, yet is much below the overcurrent tripping current level which would cause damage to the conductors of the circuit 12.
By selecting a value for the resistor 38 which yields a current under normal voltage conditions far in excess of the ground fault interrupter tripping current level, sufficient margin is provlded to insure that under emergency conditions (during which time the line voltage may drop dramatically) the current through the resistor 38 will still be sufficient to trip the breaker. The disclosed invention could, of course, be used on a multiphase circuit protected by a multiphase ground fault circuit breaker. It ~ -6-47,362 would then only be necessary to provide a flow o~ current ~rom one Or the phases to ground. r~he Gircuit breaker would trip regardless of which phase ~as selected.
The resistor 38 i~s~ cf course, not necessary for the operation of the invention~ Ho~ever, the presence of the resistor limits the level of ground current which will flow, thereby allowing the use of inexpensive low current rating contacts 36. Other impedance means could also be used in place of the resistor 38 to provide this current-limiting function.
By installing the ground current initiating meansin the plug 20, a variety of advantages is obtained. The plug can be placed in any or all of the receptacles 14 upon the circuit 12. The cost of each plug 20 is much lower than the cost of providing prior art emergency power interrupting buttons requiring separate wiring to a circuit breaker trip coil. In addition, if a temporary remote panic button is re-quired, it can be provided in a simple, convenient manner through the use of a standard extension cord plugged into the receptacle 14 and inserting the plug 20 in the other end of the extension cord. The plug 20 can then be moved to wherever emergency power interruption capability is required.
Furthermore, a single plug 20 can be carried by an operator to any deslred :Location having a receptacle 14.
It can be seen, there~ore, that the present invention provides an emergency power interruption system which can be installed at extremely lol~ cost upon existing power circuits having ground rault circuit protection. Furthermore, the present inventi.on provides a highly flexi~le and convenient means Or providing emergency power interruptlon capability at a wide variety of locations.
Claims (9)
1. A safety device for deenergizing an associated electrical power circuit, the power circuit having a phase conductor, a neutral conductor, a ground conductor, and a plurality of receptacles connected to the conductors for receiving connecting plugs of electrical apparatus to be powered by the circuit; and the power circuit being protected by a ground fault circuit interrupter adapted to trip upon detection of ground fault current above a pre-determined level, said safety device comprising:
a multi-pin plug adapted for insertion into one of the receptacles whereby each pin of said plug becomes electrically connected to one of the conductors;
a switch disposed in said plug and being elec-trically connected between the pins of said plug which are electrically connected to the phase conductor and the ground conductor; and impedance means connected in series with said switch and having a value such that closing of said switch is operable to cause a flow of ground fault current sub-stantially greater than said predetermined level, whereby said ground fault circuit interrupter is tripped when said switch is closed even under conditions of low circuit voltage.
a multi-pin plug adapted for insertion into one of the receptacles whereby each pin of said plug becomes electrically connected to one of the conductors;
a switch disposed in said plug and being elec-trically connected between the pins of said plug which are electrically connected to the phase conductor and the ground conductor; and impedance means connected in series with said switch and having a value such that closing of said switch is operable to cause a flow of ground fault current sub-stantially greater than said predetermined level, whereby said ground fault circuit interrupter is tripped when said switch is closed even under conditions of low circuit voltage.
2. A device as recited in claim 1 wherein said switch comprises a normally open momentary contact push-button.
3. A device as recited in claim 2 wherein said impedance means comprises a resistor.
4. A device as recited in claim 3 wherein said resistor has a value selected to allow ground current 47,362 to flow of at least twice said predetermined level.
5. A device as recited in claim 4 wherein said switch comprises a normally open momentary contact push-button switch.
6. An emergency power interrupter system for use on an electrical power circuit having a phase conductor, a neutral conductor, and a ground conductor, said system comprising:
a ground fault circuit breaker adapted to interrupt load current flow through said circuit upon detection of ground fault current above a predetermined level;
a multiple-terminal receptacle having one terminal connected to the phase conductor and one terminal connected to the ground conductor;
a removable plug inserted into said receptacle and comprising a first pin in removable electrical contact with said phase conductor terminal, a second pin in removable electrical contact with said ground terminal, and the series combination of impedance means and a switch connected between said first and second pins, said impedance means sized to permit ground fault current substantially greater than said predetermined level when said switch is closed, where-by said ground fault circuit breaker will interrupt load current flow when said switch is actuated even upon con-ditions of subnormal voltage upon said circuit.
a ground fault circuit breaker adapted to interrupt load current flow through said circuit upon detection of ground fault current above a predetermined level;
a multiple-terminal receptacle having one terminal connected to the phase conductor and one terminal connected to the ground conductor;
a removable plug inserted into said receptacle and comprising a first pin in removable electrical contact with said phase conductor terminal, a second pin in removable electrical contact with said ground terminal, and the series combination of impedance means and a switch connected between said first and second pins, said impedance means sized to permit ground fault current substantially greater than said predetermined level when said switch is closed, where-by said ground fault circuit breaker will interrupt load current flow when said switch is actuated even upon con-ditions of subnormal voltage upon said circuit.
7. A system as recited in claim 6 wherein said impedance means is sized to permit ground fault current flow of at least twice said predetermined level when said switch is actuated during normal voltage conditions upon 47,362 said circuit.
8. A system as recited in claim 7 wherein said impedance means comprises a resistor.
9. A system as recited in claim 8 wherein said switch comprises a normally open momentary-contact push-button switch.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US85899077A | 1977-12-09 | 1977-12-09 | |
| US858,990 | 1986-05-02 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1127747A true CA1127747A (en) | 1982-07-13 |
Family
ID=25329694
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA313,708A Expired CA1127747A (en) | 1977-12-09 | 1978-10-18 | Wireless emergency power interrupting system |
Country Status (11)
| Country | Link |
|---|---|
| JP (2) | JPS5487833A (en) |
| AU (1) | AU533221B2 (en) |
| BE (1) | BE872643A (en) |
| BR (1) | BR7807900A (en) |
| CA (1) | CA1127747A (en) |
| ES (1) | ES475803A1 (en) |
| FR (1) | FR2411497A1 (en) |
| GB (1) | GB2010496B (en) |
| IT (1) | IT1107373B (en) |
| PH (1) | PH20495A (en) |
| ZA (1) | ZA786652B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5396505A (en) * | 1993-07-06 | 1995-03-07 | Tandem Computers Incorporated | Programmable error-checking matrix for digital communication system |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2586137B1 (en) * | 1985-08-06 | 1987-12-11 | Merlin Gerin | REMOTE OPENING OF A DIFFERENTIAL PROTECTION DEVICE, IN PARTICULAR OF A DIFFERENTIAL CONNECTION CIRCUIT BREAKER |
| EP0215969A1 (en) * | 1985-09-21 | 1987-04-01 | MOTORI ELETTRICI ROTOS S.p.A | A ciruit arrangement for sensing, transmitting, and processing information of the occurrence of a variation in a parameter of AC electric equipment to be monitored |
| IL97694A0 (en) * | 1991-03-27 | 1992-06-21 | Amit Electronics & Engineering | Device and method for gfci time response and ground test |
| ES2233185B1 (en) * | 2003-07-18 | 2006-02-16 | Emilio Haba Armero | DEVICE FOR VERIFYING DIFFERENTIAL SWITCHES IN A LOW VOLTAGE INSTALLATION. |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT308225B (en) * | 1968-11-15 | 1973-06-25 | Felten & Guilleaume Schaltanl | Protective circuit for portable consumer devices connected to earthed networks |
| GB1337806A (en) * | 1971-07-07 | 1973-11-21 | Mcmillan R D | Socket testers |
| JPS562311Y2 (en) * | 1972-02-24 | 1981-01-19 | ||
| JPS5018071B2 (en) * | 1972-03-28 | 1975-06-26 | ||
| US3898557A (en) * | 1973-11-12 | 1975-08-05 | Daltec Systems Inc | Electrical device for testing a ground fault circuit interrupter |
-
1978
- 1978-10-18 CA CA313,708A patent/CA1127747A/en not_active Expired
- 1978-11-27 ZA ZA00786652A patent/ZA786652B/en unknown
- 1978-11-28 PH PH21857A patent/PH20495A/en unknown
- 1978-11-30 BR BR7807900A patent/BR7807900A/en unknown
- 1978-12-05 AU AU42219/78A patent/AU533221B2/en not_active Expired
- 1978-12-06 FR FR7834379A patent/FR2411497A1/en not_active Withdrawn
- 1978-12-07 GB GB7847561A patent/GB2010496B/en not_active Expired
- 1978-12-07 ES ES475803A patent/ES475803A1/en not_active Expired
- 1978-12-07 IT IT41680/78A patent/IT1107373B/en active
- 1978-12-08 JP JP15118478A patent/JPS5487833A/en active Pending
- 1978-12-08 BE BE192229A patent/BE872643A/en not_active IP Right Cessation
-
1982
- 1982-02-17 JP JP1982020028U patent/JPS6145696Y2/ja not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5396505A (en) * | 1993-07-06 | 1995-03-07 | Tandem Computers Incorporated | Programmable error-checking matrix for digital communication system |
Also Published As
| Publication number | Publication date |
|---|---|
| BE872643A (en) | 1979-06-08 |
| AU533221B2 (en) | 1983-11-10 |
| BR7807900A (en) | 1979-07-31 |
| JPS6145696Y2 (en) | 1986-12-23 |
| JPS5487833A (en) | 1979-07-12 |
| AU4221978A (en) | 1979-06-14 |
| IT7841680A0 (en) | 1978-12-07 |
| PH20495A (en) | 1987-01-21 |
| JPS57175542U (en) | 1982-11-06 |
| ES475803A1 (en) | 1979-12-01 |
| GB2010496B (en) | 1982-03-24 |
| GB2010496A (en) | 1979-06-27 |
| FR2411497A1 (en) | 1979-07-06 |
| ZA786652B (en) | 1979-11-28 |
| IT1107373B (en) | 1985-11-25 |
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Legal Events
| Date | Code | Title | Description |
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| MKEX | Expiry |