Abstract:
The present invention provides a circuit interrupting device which contains four pairs of contacts to electrically connect/disconnect to an input power source to a user accessible load and an output power end. The present invention also provides a simulated leakage current generating switch, which is capable of automatically generating a simulated current to test the circuit interrupting device when the power lines are properly wired and in a tripped state. The present invention further provides a reset switch which allows reset when the power lines are properly wired and the reset button is depressed. In addition, the present invention provides a dual-functioned test button which can manually generate a simulated leakage current when a first-level test button is depressed, and can perform a mechanical trip when a second-level test button is depressed.

Description:
RELATED APPLICATION 
     This application claims the priority of Chinese patent application No. 200720169660.8, which was filed on Oct. 7, 2007, which is herein incorporated by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to a circuit interrupting device which contains four pairs of contacts to electrically connect/disconnect to an input power source to a user accessible load and an output power end. The present invention also relates to a simulated leakage current generating switch, which is capable of automatically generating a simulated current to test the circuit interrupting device when the power lines are properly wired. The present invention further relates to a reset switch which allows reset when the power lines are properly wired and the reset button is depressed. In addition, the present invention relates to a dual-functioned test button which can manually generate a simulated leakage current when a first-level test button is depressed, and can perform a mechanical trip when a second-level test button is depressed. 
     BACKGROUND OF THE INVENTION 
     Ground fault circuit interrupter (GFCI) devices are required in most residential and commercial applications where a possible wiring defect or other electrical fault could expose a consumer to shock or electrocution. GFCI devices, like any electromechanical device, can experience an end-of-life condition when the device&#39;s internal components fail and lose their protective functions. 
     In the invention to be described below, a novel ground fault circuit interrupter is introduced, which is capable of automatically generating a simulated leakage current when certain conditions are met. 
     SUMMARY OF THE INVENTION 
     The present invention provides a circuit interrupting device, preferably a ground fault circuit interrupter (GFCI), which comprises (1) a pair of power output conductors extended to electrically connect to user accessible load ends; (2) a first pair of flexible metal pieces where an end of each of the first pair of flexible metal pieces is obliquely connected to a printed circuit board and further electrically connected to a metal piece, which is electrically connected to said input power source, and where another end of each of the first pair of flexible metal pieces is capable of connecting/disconnecting to each of the pair of power output conductors; (3) a second pair of flexible metal pieces where an end of each of the second pair of flexible metal pieces is electrically connected to the output power source and where another end of each of the second pair of flexible metal pieces is capable of connecting/disconnecting to each of said pair of power output conductors. An electrical continuity is established or discontinued when the first pair of flexible metal pieces is connecting/disconnecting to the pair of power output conductors, and the second pair of flexible metal pieces is connecting/disconnecting to the pair of power output conductors. 
     Each of the pair of power output conductors comprises a pair of fixed contacts. The pair of fixed contacts on each of said pair of output conductors is perpendicular to said power output conductors. Each of the first pair of flexible metal pieces has a movable contact which is capable of connecting/disconnecting to each of the fixed contacts on the pair of power output conductors. Each of the second pair of flexible metal pieces has a movable contact which is capable of connecting/disconnecting to each of the fixed contacts on the pair of power output conductors. 
     The metal piece that is capable of electrically connecting to one of the first pair of flexible metal piece is preferably in a U-shape and can pass through a differential transformer. 
     The circuit interrupting device further comprises a tripping mechanism, which is located underneath a reset button. The tripping mechanism comprises a reset support piece and a tripping device. The reset support piece is located above the tripping device which provides supports for the first and the second pairs of flexible metal pieces. The tripping device moves when the reset button is depressed. The reset support piece is shaped like a “I”, where a top dimension of the reset support piece is smaller than a bottom dimension. Each of the first and the second pairs of flexible metal pieces further comprises a semicircular protruding piece which allows the first and the second pairs of the flexible metal pieces to sit on top of the reset support piece. 
     The reset support piece and the tripping device contain through holes which are aligned to allow a directional lock from underneath the reset button to pass through. The directional lock is capable of passing through a hole in a locking member, which penetrates through the middle section of the tripping device when a rest button is depressed and the solenoid coil is energized to reset the circuit interrupting device. 
     The circuit interrupting device further comprises a reset status light that lights when the device is capable of being reset; and a power status light that lights to indicate that the device has power output. 
     The present invention further provides a circuit interrupting device which comprises a simulated leakage current generating switch (KR- 1 ) which contains a first switch piece; a second switch piece; and a third switch piece. When the circuit interrupting device is properly wired and in a tripped state, the first switch piece is in contact with the second switch piece, which automatically generates a simulated leakage current to test the components of the circuit interrupting device. If all of the components tested are working properly, the circuit interrupting device can be reset. 
     The first switch piece is in series with a resistor which is electrically connected to a neutral line of said input power source. The first switch piece has a contact located at an upper end of the first switch piece. The second switch piece is electrically connected to a hot line of the input power source via a solenoid coil. The second switch piece has two contacts located at an upper and a lower ends of the second switch piece. The third switch piece is electrically connected to the neutral line of the input power source through a silicon controlled rectifier (SCR). The third switch piece has a contact located at a lower end of said third switch piece. The first, second, and third switch pieces are located next to a tripping device beneath the reset button and are triangularly arranged with the first switch piece located at the bottom, the second switch piece situated in the middle, and the third switch piece located at the top. 
     The components of the circuit interrupting device that can be tested due to the simulated leakage current are preferably SCR and solenoid coil, and further include a differential transformer and a leakage current detection IC chip. 
     The circuit interrupting device further comprises a reset status light that lights when the device is capable of being reset; and a power status light that lights to indicate that the device has power output. 
     In addition, the present invention provides a circuit interrupting device which comprises a reset switch (KR- 4 ) which is located below a reset button. The reset switch comprises a flexible metal piece and an electric contact. When the reset button is in a tripped state, the flexible metal piece and the electric contact do not come into contact so that the reset switch is in a disconnected state. When the power lines are properly wired and the reset button is depressed, the flexible metal piece and the electric contact come into contact with each other to allow reset. The reset switch is coupled to a solenoid coil and is serially connected to a simulated leakage current generating switch. The circuit interrupting device further comprises a reset status light that lights when the device is capable of being reset; and a power status light that lights to indicate that the device has power output. 
     Finally, the present invention provides a circuit interrupting device which comprises a dual-function test button which provides a manual test of components of the circuit interrupting device when a first-level test button is depressed, and provides a mechanical tripping mechanism when a second-level test button is depressed. 
     The test button has an arm extended downward to connect to a sliding block and a test switch (KR- 5 ). The test switch comprises a first flexible metal switch piece and a second flexible metal switch piece. When the interrupting device is properly wired (i.e., that the device is powered) and in the reset state, a depression of the test button at the first-level causes the test switch to be activated to manually test the components of the interrupting device. When the circuit interrupting device is not properly wired and in a reset state, a depression of the test button at the second-level allows the sliding block to rotate to manually cause the circuit interrupting device to trip. 
     One end of the first flexible metal switch piece of the test switch is electrically connected to one power output end (e.g., the hot power output end) and the other end is suspended in the air. One end of the second flexible metal switch of the test switch is electrically connected to the other power input end (e.g., the neutral power input end) through a resistor, and the other end is suspended in the air. When the test button is depressed, the first flexible metal switch piece is in contact with the second flexible metal switch piece to initiate a test of the circuit interrupting device. 
     The sliding block has a pair of protrusions on two sides that act as rotating axles. It further has an handle which is adapted to connect to a locking member of a tripping device in connection with the reset button. When the test button is depressed at a second-level, the sliding block mechanically moves the locking member so as to mechanically trip the circuit interrupting device. The circuit interrupting device further comprises a reset status light that lights when the device is capable of being reset; and a power status light that lights to indicate that the device has power output. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The detailed description will refer to the following drawings in which like numerals refer to like items, and in which: 
         FIG. 1  is an exploded cubic schematic of the structure of an embodiment of a GFCI device; 
         FIG. 2  is the main view of the GFCI device of  FIG. 1 ; 
         FIG. 3  is the front view of the GFCI device of  FIG. 1  with the upper cover removed; 
         FIG. 4  is an illustration of the relationships among the power input metal pieces, power output conductors, and flexible connecting output metal pieces of the GFCI device of  FIG. 1 ; 
         FIG. 5  is an illustration of the relationships among the parts on the circuit board of the GFCI device of  FIG. 1 ; 
         FIG. 6  is an exploded cubic schematic of the structure of an embodiment of a reset/tripping mechanical device of the GFCI device of  FIG. 1 ; 
         FIG. 7-1  is a partial cross-sectional view along the B-B line in  FIG. 3  illustrating relationships among the parts when the GFCI device works initially with no power output; 
         FIG. 7-2  is a partial cross-sectional view along the B-B line in  FIG. 3  illustrating relationships among the parts the instant the reset button is pressed; 
         FIG. 7-3  is a partial cross-sectional view along the B-B line in  FIG. 3  illustrating relationships among the parts when the reset button is reset and the GFCI device works normally with power output; 
         FIG. 8-1  is a partial cross-sectional view along the B-B line in  FIG. 3  illustrating relationships among the parts when the GFCI is reset with power output in the outlets of the user accessible load; 
         FIG. 8-2  is a partial cross-sectional view along the B-B line in  FIG. 3  illustrating relationships among the parts when the test button is pressed, the GFCI device works normally, and the reset button is released with no power output from the GFCI device; 
         FIG. 8-3  is a partial cross-sectional view along the B-B line in  FIG. 3  illustrating relationships among the parts when the test button is pressed, the GFCI device has come to the end of its life, and the reset button does not trip/release and the GFCI device still has power output; 
         FIG. 8-4  is a partial cross-sectional view along the B-B line in  FIG. 3  illustrating relationships among the parts when the GFCI is at the reset position and the test button has been repeatedly pressed to force a mechanical trip so as to disconnect the power to the user accessible load; 
         FIG. 9-1  is a partial cross-sectional view along the C-C line in  FIG. 3  illustrating relationships among the parts when the test button is pressed, the GFCI device has come to the end of its life, and the reset button does not trip/release and the GFCI device still has a power output; 
         FIG. 9-2  is a partial cross-sectional view along the C-C line in  FIG. 3  illustrating relationships among the parts when the GFCI is at the reset position and the test button has been repeatedly pressed to force a mechanical trip so as to disconnect the power to the user accessible load; 
         FIG. 10-1  is a partial cross-sectional view along the A-A line in  FIG. 3  illustrating relationships among the parts when the reset button is in a released state; 
         FIG. 10-2  is a partial cross-sectional view along the A-A line in  FIG. 3  illustrating relationships among the parts the instant the reset button is pressed; 
         FIG. 10-3  is a partial cross-sectional view along the A-A line in  FIG. 3  illustrating relationships among the parts the instant when the reset button is in a reset state; 
         FIG. 11  is a wiring diagram of a control circuit of the GFCI device of  FIG. 1 ; and 
         FIG. 12  is another wiring diagram of a control circuit of the GFCI device of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Ground fault circuit interrupter (GFCI) devices are required in most residential and commercial applications where a possible wiring defect or other electrical fault could expose a consumer to shock or electrocution. GFCI devices, like any electro-mechanical device, can experience an end-of-life condition when the device&#39;s internal components fail and lose their protective functions. However, current GFCI devices lack an end of life test function. In addition, when they reach an end of life condition, these GFCI devices do not have any mechanism for indicating that condition to a user. The reset buttons of these end of life GFCI devices may still be reset. The load output ends and the single phase, three line output sockets on the surfaces of these GFCI devices will still have a power output, misleading users into continuing to use the GFCI devices. When there is a leakage current, such an end of life GFCI device cannot provide its normal protective functions, thereby increasing the risk to the user of electrical shock and electrocution. 
     In addition, some of the current GFCI devices do not include mechanisms that prevent reverse wiring errors. When an installer erroneously connects the hot power line and neutral power line inside a wall to the power output ends of a current GFCI devices, the single phase, three line output socket on the surface of the device has a power output, but the current flowing through the device does not flow through the electric leakage current protection circuit installed inside the device. Therefore, when reversed wired, the GFCI device cannot protect against electric leakage current, and when such electric leakage current exists, the user is exposed to an increased risk of electric shock and electrocution. 
       FIG. 1  is an exploded view of an embodiment of an improved GFCI device that addresses the aforementioned limitations of current GFCI devices by incorporating end of life and reverse wiring features. Although  FIG. 1  shows a GFCI device, the disclosed end of life and reverse wiring protective features also could be incorporated into an arc fault circuit interrupter, an immersion detection circuit interrupter, an appliance leakage circuit interrupter, and a circuit breaker, for example. 
     The GFCI device of  FIG. 1  includes a housing and a circuit board  18  installed inside the housing capable of achieving a ground fault circuit interruption with or without a power output from the GFCI device. The GFCI housing includes a combination of upper cover  2 , insulated middle support  3  and base  4 . Metal mounting strap  1  is positioned between upper cover  2  and middle support  3 . The circuit board  18  is positioned between the insulated middle support  3  and the base  4 . 
     As shown in  FIGS. 1 and 2 , power output sockets  5 ,  6 , reset button hole  8 -A, test button hole  7 -A, and status indicating light hole  30 -A are formed on the upper cover  2 . Reset button (RESET)  8  and test button (TEST)  7  are installed in reset button hole  8 -A and test button hole  7 -A, respectively. Reset button  8  and test button  7  penetrate through metal mounting strap  1  and insulated middle support  3  to make contact with circuit board  18  components. Four hooks  2 -A are arranged on the side of the upper cover  2  to hook into slots  4 -B on base  4 . 
     Metal mounting strap  1  is grounded through grounding screw  13 -A (as shown in  FIGS. 1 and 2 ). Grounding pieces  11 ,  12  are arranged on metal mounting strap  1  at locations corresponding to the grounding holes of power output sockets  5 ,  6  of the upper cover  2 . 
     As shown in  FIGS. 1 and 3 , a hot power output conductor  14  and a neutral power output conductor  13  are installed on the two sides of the insulated middle support  3 . At the two ends of power output conductors  13 ,  14 , gripping wing pieces  60 ,  61 ,  62 ,  63  are arranged at places corresponding to the hot and neutral holes of power output sockets  5 ,  6  on the upper cover  2 . As shown in  FIGS. 1 ,  3 ,  4 , and  7 - 1 , on both ends of neutral power output conductor  13 , using the center of the tripping device on circuit board  18  as a center point, at locations greater than the width of tripping device  28  and perpendicular to the body of neutral power output conductor  13 , side walls extend horizontally. As shown in  FIGS. 1 ,  3 ,  4 , and  9 - 1 , on hot power line output conductor  14 , using the center of the tripping device on circuit board  18  as a center point, at locations greater than the width of tripping device  28  and perpendicular to the body of hot power line output conductor  14 , side walls extend horizontally. Fixed contacts  15 ,  52  and  16 ,  53  are arranged on side walls of power output conductors  13  and  14 , respectively, to form two pairs of fixed contacts  15 ,  16  and  52 ,  53 . 
     As shown in  FIG. 1 , base  4  is used to accommodate insulated middle support  3  and circuit board  18 . A pair of neutral and hot power input wiring screws  9 ,  10  and a pair of neutral and hot power output wiring screws  109 ,  110  are installed symmetrically on the two sides of base  4 . 
     The circuit board  18  functions to cause power outlet sockets  5  and  6  on the upper cover  2  of the GFCI device and power output wiring screw  109  and  110  on the sides of the base  4  to have or not to have power output. The circuit board  18  also functions to test whether the GFCI device has come to the end of its life, display the test result, and to forcibly release the GFCI device through mechanical means, and to prevent reverse wiring errors. 
     As shown in  FIGS. 1 ,  4 ,  5  and  7 - 1 , obliquely placed, flexible neutral power line and hot power line input metal pieces  50  and  51  are placed on circuit board  18 . One end  50 C of obliquely placed flexible neutral power line input metal piece  50  is welded onto one end of “U” shaped neutral power line input metal connecting piece  50 - 1 . The other end is inclined upward. A moving contact  54  is placed in the end section of the upwardly inclined end, at a location corresponding to fixed contact  52  on neutral power output conductor  13 . The other end  50 D of “U” shaped neutral power line input metal connecting piece  50 - 1  threads through differential transformer  19 , and is welded onto circuit board  18  together with metal piece  24 . The welded together parts  24  and  50 D then connect to a neutral power line input wiring screw  9 . Neutral power line input wiring screw  9  connects to a neutral power source. Similarly, as shown in  FIGS. 1 ,  4 ,  5 , and  9 - 1 , one end  51 B of obliquely placed, flexible hot power line input metal piece  51  is welded onto one end of “U” shaped the hot power line input metal connecting piece  51 - 1 . The other end is inclined upward. A moving contact  55  is placed in the end section of the piece  51 - 1 , at a location corresponding to fixed contact  53  on the hot power line output conductor  14 . The other end  51 A of “U” shaped hot power line input metal connecting piece  51 - 1  threads through differential transformer  19  and is welded together with metal piece  25  onto circuit board  18 . The welded together parts  25  and  51 A then connect to a hot power line input wiring screw  10 . Hot power line input wiring screw  10  is connected to the hot power source. As shown in  FIGS. 3 and 4 , moving contacts  54  and  55  on flexible power input metal pieces  50  and  51 , respectively, correspond to fixed contacts  52  and  53 , respectively placed on power output conductors  13  and  14  on middle support  3 , with which they form two pairs of hot line and neutral line power switches. 
     As shown in  FIGS. 1 ,  4 , and  5 , two obliquely placed flexible connecting output metal pieces  20  and  21  are also placed on circuit board  18 . As shown in FIGS.  1  and  7 - 1 , one end of obliquely placed flexible connecting output metal piece  20  comes into contact with neutral power line output end  80 . Together, they are welded onto the circuit board  18  and are connected to neutral power line output wiring screw  109 . The other end of piece  20  is inclined upward, and moving contact  22  is placed in the end section of the upwardly inclined end of piece  20 . The moving contact  22  corresponds to fixed contact  15  on neutral power output conductor  13  (as shown in  FIGS. 3 and 4 ), with which it forms a power switch. Similarly, as shown in FIGS.  1  and  9 - 1 , one end of obliquely placed flexible connecting output metal piece  21  comes into contact with hot power line output end  81 . Together, they are welded onto circuit board  18  and are connected to hot power line output wiring screw  110 . The other end of piece  21  is inclined upward, and moving contact  23  is placed in the end section of the upwardly inclined end of piece  21 . The moving contact  23  corresponds to fixed contact  16  on hot power line output conductor  14  (as shown in  FIGS. 3 and 4 ), with which it forms a power switch. 
     As shown in  FIGS. 3 and 4 , moving and fixed contacts on the flexible power input metal pieces  50  and  51 , power output conductors  13  and  14 , and flexible connecting output metal pieces  20  and  21  form a total of two groups, and four pairs, of neutral line and hot line power switches:  54  and  52 ,  22  and  15 ,  55  and  53 , and  23  and  16 . These switches correspond, respectively, to switches KR- 2 - 2 , KR- 3 - 2 , KR- 2 - 1  and KR- 3 - 1  in the wiring diagrams shown in  FIGS. 11 and 12 . 
     As shown in  FIGS. 1 ,  5  and  7 - 1 , differential transformer  19  on circuit board  18  is used for detecting leakage current. As shown in  FIG. 11  and  FIG. 12 , the hot power line HOT and neutral line WHITE thread through differential transformer  19  (L 1  and L 2  in  FIGS. 11 and 12 ). When a leakage current exists on the power supply loop, the differential transformer  19  outputs a voltage signal to the leakage current detection control chip IC (such as model No. RV4145, for example). Pin  5  of the control chip IC outputs a control signal to silicon controlled rectifier (SCR), causing a reset/tripping mechanical device on circuit board  18  to act, thereby releasing the reset button  8  and tripping the GFCI device, which cuts off the power output of the GFCI device. 
     As shown in  FIGS. 1 ,  5 ,  6 ,  7 - 1  and  10 - 1 , a reset/tripping mechanical device, placed on circuit board  18 , causes flexible power input metal pieces  50  and  51  to be electrically connected to or disconnected from power output conductors  13  and  14 . This device also causes flexible connecting output metal pieces  20  and  21  to energize or de-energize through power output conductors  13  and  14 , which in turn causes power output ends  80  and  81  to energize or de-energize. The reset/tripping mechanical device includes an “I” shaped plastic reset support piece  28 A, a “T” shaped tripping device  28  coupled to reset button  8 , locking member  30 , locking member spring  34 , reset directional lock  35 , reset spring  91 , quick tripping spring  66 -A, simulated leakage current generation switches  66 ,  67 , and  88 , reset switches  72  and  72 A and reset lift spring  71  coupled to the reset button  8 , flexible metal switch pieces  46  and  47  coupled to the test button  7 , sliding block  37 , and solenoid coil  26 . 
     The “I” shaped plastic reset support piece  28 A is located directly below reset button  8  and directly above the “T” shaped tripping device  28 . The upper surface area of the two larger ends of the “I” shaped reset support piece  28 A is smaller than the lower surface area, with oblique planes  20 B forming the sides of the “I” shaped reset support piece  28 A. As shown in  FIG. 7-1 , the end of flexible neutral power line input metal piece  50  that is inclined upward and the end of flexible connecting output metal piece  20  that is inclined upward lean against oblique planes  20 B on the two sides of one end of the “I” shaped reset support piece  28 A in a “herringbone” fashion. A semicircular protruding point  20 A is placed in the upper part of the side of oblique plane  20 B on neutral power line input metal piece  50  where piece  50  comes into contact with the oblique plane  20 B on one side of the “I” shaped reset support piece  28 A. Another semicircular protruding point  20 A is placed in the upper part of the side of oblique plane  20 B on flexible connecting output metal piece  20  where piece  20  comes into contact with oblique plane  20 B on the other side of the “I” shaped reset support piece  28 A. 
     As shown in  FIG. 9-1 , one end of flexible hot power line input metal piece  51  that is inclined upward and one end of flexible connecting output metal piece  21  that is inclined upward lean against oblique planes  20 B on the two sides of the other end of the “I” shaped reset support piece  28 A in a “herringbone” fashion. A semicircular protruding point  20 A is placed in the upper part of the side of oblique plane  20 B on hot power line input metal piece  51  where piece  51  comes into contact with oblique plane  20 B on one side of the “I” shaped reset support piece  28 A. Another semicircular protruding point  20 A is placed in the upper part of the side of oblique plane  20 B on flexible connecting output metal piece  21  where metal piece  21  comes into contact with oblique plane  20 B on the other side of the “I” shaped reset support piece  28 A. 
     As can be seen in FIGS.  6  and  9 - 1 , through holes  28 B are placed on the left and right ends of the “I” shaped reset support piece  28 A. A straight through hole  29 A is placed in the middle of the “I” shaped reset support piece  28 A allowing reset directional lock  35  to thread through the “I” shaped reset support piece  28 A. A quick tripping spring  66 -A is placed above the straight through hole  29 A. When the reset button  8  is in a released state, pushed up by quick tripping spring  66 -A, the “I” shaped reset support piece  28 A is placed on the placement spacer in a fixed position set aside for it on coil framework  26 K. 
     The “T” shaped tripping device  28  is located directly below the “I” shaped reset support piece  28 A and is coupled to reset button  8 . The “T” shaped tripping device  28  extends outward on the left and right sides to form two lifting arms. Round platform shaped protrusions  28 F are placed on the left and right lifting arms. The round platform shaped protrusions  28 F can move up and down inside through holes  28 B on reset support piece  28 A, causing reset support piece  28 A to be in contact with tripping device  28  or to be separated from the tripping device  28 . 
     A central through hole  29  penetrates device  28  top to bottom in line with through hole  29 A. A reset spring  91  is slid onto the reset directional lock  35  and contacts the bottom surface of the reset button  8 . The reset directional lock  35  can move up and down through holes  29 A and  29  through the “I” shaped reset support piece  28 A and tripping device  28 , respectively. Reset spring  91  also passes through a round center hole on the middle support  3 , through which the reset directional lock  35  moves. Quick tripping spring  66 -A is pressed down in the lower part of the middle support  3  and directly below the center hole. 
     A circle of recessed lock slots  36  are formed in the lower part of reset directional lock  35  near its bottom. Bottom surface  41  of reset directional lock  35  is forms a plane. As shown in  FIG. 6 , a through hole  30 E is opened in the middle section of tripping device  28 . A movable “L” shaped locking member  30 , having a downwardly projecting section, and preferably made of metal materials, is located in through hole  30 E. A locking member hole  31  is formed on the top surface of locking member  30 . The bottom surface  41  of reset directional lock  35  is in a staggered state with locking member hole  31  on the top surface of locking member  30 . 
     A locking member spring  34  is placed between the inside walls of tripping device  28  and the downwardly projecting section of locking member  30 . A solenoid coil  26  with an iron core  42  is placed in proximity to the locking member  30 . Iron core  42  directly faces the downwardly projecting section of locking member  30 . Under the action of iron core  42 , locking member  30  can move horizontally, thus enabling the reset directional lock  35  to thread in or out of the hole  31  of locking member  30 . Reset button  8  occupies one of two positions: reset or released (tripped). Tower shaped spring  42 A is slid onto the end section iron core  42 . 
     Tripping device  28  is accommodated in accommodation slot  26 F of the coil framework  26 K. A reset lift spring  71  is placed between the bottom of tripping device  28  and the bottom of slot  26 F. 
     As shown in FIGS.  6  and  10 - 1 , a simulated leakage current generation switch (switch KR- 1  in  FIGS. 11 and 12 ) coupled to reset button (RESET)  8  is placed next to tripping device  28 . The simulated leakage current generation switch includes three triangularly arranged flexible metal pieces  66 ,  67  and  88 . A contact  68 C, formed through punching, is placed on the upper surface of metal piece  66 . Contacts  68 A and  68 B are respectively placed on the upper and lower surfaces of flexible metal piece  88 . A contact  67 A is placed on the lower surface of metal piece  67 . A contact pin  28 E extends downward from one corner of the “I” shaped reset support piece  28 A. When the interrupter is not reset, pushed and pressed by quick tripping spring  66 -A, reset support piece  28 A stays in the placement spacer in a fixed position on the coil framework set aside for it, causing contact pin  28 E just to press down on the flexible metal piece  88 . 
     As shown in  FIGS. 10-1  and  10 - 2 , when reset button  8  is in its released state, that is, when the reset button  8  is not reset, since reset support piece  28 A is blocked by the placement spacer in a fixed position on the coil framework  26 K, the reset support piece  28 A stays in the placement spacer. Contact pin  28 E extending downward from the “I” shaped reset support piece  28 A causes contact  68 B on the lower surface of flexible metal piece  88  to stay in contact with contact  68 C and become conducting. When the reset button  8  goes from the released state to a reset state, as shown in  FIG. 10-3 , tripping device  28  moves up, driving the “I” shaped reset support piece  28 A to move up and causing contact pin  28 E to concurrently move away from the upper surface of flexible metal piece  88 . Under its own flexible action, flexible metal piece  88  causes contact  68 B on its lower surface to disconnect from contact  68 C on the upper surface of metal piece  66 . Contact  68 A on the upper surface of flexible metal piece  88  comes into contact with contact  67 A on the lower surface of metal piece  67  and become conducting. 
     As shown in  FIGS. 11 and 12 , metal piece  66  is connected to the neutral input line through simulated leakage current limiting resistor R 4 . Metal piece  88  in its middle is connected to the input hot line through solenoid coil SOL  26 . Metal piece  67  is connected to the neutral line on the power input end through the SCR V 4  on the leakage current detection circuit. Therefore, after the power input end of the GFCI device is properly connected to the power source, the hot line, the solenoid coil SOL  26 , metal piece  88 , metal piece  66 , resistor R 4 , the neutral line that threads through differential transformers L 1  and L 2  form a simulated leakage current generating loop that, without the need to operate any part of the GFCI device, can automatically generate a simulated leakage current to detect whether the GFCI device has come to the end of its life. If the GFCI device has not come to the end of its life, reset indicator V 5  is lit. If the GFCI device has come to the end of its life, the reset button  8  cannot be reset and reset indicator V 5  is not lit. After reset button  8  is reset, metal piece  88  is disconnected from metal piece  66 , comes into contact with metal piece  67 , and becomes conducting, thereby removing the simulated leakage current. 
     As shown in FIGS.  6  and  10 - 1 , a reset switch (KR- 4  in  FIGS. 11 and 12 ) is coupled to reset button  8  and is placed below tripping device  28 . The reset switch includes flexible metal piece  72  and contact  72 A. The reset switch is serially connected into the leakage current detection circuit. When reset button  8  is in a released state, flexible metal piece  72  and contact  72 A are not in contact and the reset switch is open. When reset button  8  is pressed down, tripping device  28  and reset lift spring  71  are pressed down, causing tripping device  28  to be pressed onto flexible metal piece  72 . When pressed down, flexible metal piece  72  comes into contact with contact  72 A and becomes conducting. In this condition, the reset switch is closed. When reset button  8  is released, under the elastic action of reset lift spring  71 , tripping device  28  is lifted off flexible metal piece  72 , causing flexible metal piece  72  to disconnect from contact  72 A and the reset switch is open. 
     As shown in  FIG. 7-1 , the test button  7  sits atop arm  40 A onto which spring  40  is slid. At a position close to its lower end, arm  40 A shrinks inward to form step  40 E and a small cylindrical body  40 F that continues to extend downward. A “spoon” shaped sliding block  37  is placed at the lower part of step  40 E. A through slot with a width smaller than step  40 E but greater than the diameter of small cylindrical body  40 F is placed vertically on sliding block  37  (in the area between parts numbers  37 -A and  37 -B in  FIG. 1 ). Sliding block  37  is fixed inside vertical guide slots  41 -D (see  FIG. 6 ) on two sides on the front end of solenoid coil framework  26 K. The projections  37 -D act as rotating axles (see  FIG. 6 ) and allow the sliding block  37  to rotate. Step  40 E is pressed on two sides of the aforementioned through slot to cause rotation of sliding block  37 . 
     As shown in  FIG. 7-1 , handle  37 -C of sliding block  37  is inclined upward and threads through hole  32  on the top of locking member  30  near one end of the test button  7 . Below side  37 -B opposite handle  37 -C, a pair of flexible metal switch pieces  46  and  47  (see  FIG. 6 ), form test switch KR- 5  (as shown in  FIGS. 11 and 12 ) that is used to manually generate a simulated leakage current. Small cylindrical body  40 F at the bottom of arm  40 A, pushes against flexible metal piece  46 . As shown in  FIG. 6 , one end of flexible metal piece  46  bends downward to thread through a hole opened oil solenoid coil framework  26 K and is welded onto the circuit board  18 . Through resistor R 3 , test switch KR- 5  is connected to the neutral power line. The other end of flexible metal piece  46  is unsupported. One end of flexible metal switch piece  47  is unsupported. The other end also threads through a hole opened on the solenoid coil framework  26 K and is welded onto the circuit board  18 , and connects to the power output hot line. The unsupported end of flexible metal piece  46  is located directly above the unsupported end of flexible metal switch piece  47 , and normally the two unsupported ends are not in contact. As shown in  FIGS. 7-1  through  7 - 3  and  FIG. 8-1 , when test button  7  is not pressed down, the upper ends of the flexible metal switch pieces  46  and  47  don&#39;t contact, and test switch KR- 5  ( FIGS. 11 and 12 ) is disconnected. As shown in  FIGS. 8-2  through  8 - 3  and  FIGS. 9-1  and  9 - 2 , when test button  7  is pressed down, the upper ends of flexible metal switch pieces  46  and  47  come into contact, and test switch KR- 5  is closed, thereby manually generating a simulated leakage current. 
     As shown in  FIG. 6 , tripping device  28 , simulated leakage current generation switch (pieces  66 ,  67  and  88 ), reset switch (pieces  72  and  72 A) coupled to the reset button  8 , test switch (flexible metal switch pieces  46  and  47 ) coupled to the test button  7 , and sliding block  37  all are placed inside solenoid coil framework  26 K. A solenoid coil protection cover  41 -C is placed over coil of solenoid coil  26 . Four rectangular holes  80 A and  81 A are placed on the top of cover  41 -C. Hook pins  41 -B are placed on the left and right sides of cover  41 -C, and are used to hook the cover  41 -C into holes on circuit board  18 . Slots  41 -H are respectively on the left and right of the front side of the cover  41 -C and are used to secure flexible connecting output metal pieces  20  and  21 . As shown in  FIG. 1 , protruding points  80 F and  81 F are respectively placed on the top of power output ends  80  and  81 , which in turn fit, respectively, into holes  80 A and  81 A on top of solenoid coil protection cover  41 -C. 
     Reset support piece  28 A, tripping device  28 , locking member  30 , locking member spring  34  and sliding block  37 , the simulated leakage current generation switch, the reset switch, reset directional lock  35 , reset spring  91 , quick release spring  66 -A, reset lift spring  71  and solenoid coil  26  are interconnected to form a freely movable assembly. 
       FIGS. 11 and 12  are wiring diagrams for the control circuit of the GFCI device. As shown in the wiring diagrams, the control circuit includes differential transformers L 1  (1000:1) and L 2  (200:1), which are used for detecting an electric leakage current, control chip IC (e.g., RV4145), solenoid coil  26  (SOL), with a built in iron core, silicon controlled rectifier SCR V 4 , simulated leakage current generation switch KR- 1  and reset switch KR- 4 , both of which are coupled to the reset button RESET, switches KR- 2 - 1 , KR- 2 - 2 , KR- 3 - 1  and KR- 3 - 2 , which are serially connected in the power supply line, switch KR- 5 , which is coupled to the test button TEST, reset indicator V 5 , power output indicator V 3 , and related diodes, resistor and capacitors. 
     After the hot line HOT and neutral line WHITE on the power supply line thread through differential transformers L 1  and L 2 , the leakage current detection signal output ends of differential transformers L 1  and L 2  are connected to signal input ends  1 ,  2 ,  3  and  7  of the control chip IC. Control signal output end  5  of the control chip IC is connected to the gate of SCR V 4 . The negative pole of SCR V 4  is connected to the neutral line (WHITE) of the power input end. The positive pole of SCR V 4  is connected to the hot line (HOT) through metal piece  67  of simulated leakage current generation switch KR- 1  which is coupled to the reset button RESET, and solenoid coil SOL. The iron core of solenoid coil SOL causes the reset button RESET to reset or to release through the mechanical tripping device, thus causing switches KR- 2 - 1 , KR- 2 - 2 , KR- 3 - 1  and KR- 3 - 2  to close or open. 
     A power output indicator V 3  is connected between hot power line HOT and neutral line WHITE output ends (ends  81  and  80 —see  FIG. 1 ). Reset indicator V 5  is connected in the conduction loop of SCR V 4 . 
     Power input end hot line HOT is connected to power input end neutral line WHITE that thread through differential transformers L 1  (1000:1) and L 2  (200:1) through solenoid coil  26  (SOL), metal piece  66  and  88  in simulated leakage current generation switch KR- 1  and simulated leakage current limiting resistor R 4 , forming a simulated leakage current generation circuit. This circuit makes it possible to automatically generate a simulated leakage current after the power input ends of the ground fault circuit interrupter are properly connected to the power lines without the need to operate any part of the GFCI device. 
     As shown in  FIGS. 11 and 12 , after the power input ends of the GFCI device are properly connected to the power lines and with the reset button RESET not reset and simulated leakage current generation switch KR- 1  closed (i.e., metal piece  66  and metal piece  88  have come into contact and become conducting), a simulated leakage current can be automatically generated without the need to operate any part of the GFCI device. The simulated leakage current sensed by leakage current differential transformers L 1  and L 2 . A high potential control signal is output from pin  5  of the IC to the gate of SCR V 4 , and SCR V 4  is triggered. The positive pole and the negative pole of the SCR V 4  become conducting. Reset indicator V 5 , which is connected between nodes A and B, is lit, indicating that the functions of the GFCI device are intact and that the GFCI device can provide protection against a leakage current. The reset button RESET then can be reset. By contrast, if the GFCI device has come to the end of its life, then SCR V 4  does not conduct and reset indicator V 5  is not lit. No current flows through solenoid coil  26 , and the internal iron core  42  does not act. As a result, the mechanical release device (locking member  30 ) will not act and the reset button RESET cannot be reset, thus prompting the user that the GFCI device has come to the end of its life and should be replaced with a new ground fault circuit interrupter. 
     Referring to  FIGS. 11 ,  12 , and  7 - 2 , the reset button RESET has been pressed, simulated leakage current generation switch KR- 1  has not been opened, but reset switch KR- 4  has been closed. Closing reset switch KR- 4  causes a short connection between nodes A and B, and the original voltages on both ends of AB are added to solenoid coil (SOL)  26 , thus causing current to flow through solenoid coil SOL, generating a magnetic field and causing the iron core  42  to move. As shown in  FIG. 7-3 , locking member  30  then opens and directional lock  35  threads through locking member hole  31  on locking member  30 . At the same time, light emitting diode V 5  connected between points A and B moves to an off state and light V 5  goes out. Switch KR- 1  opens (i.e., metal piece  66  and metal piece  88  move apart) and the simulated leakage current stops flowing. After this reset operation, switches KR 2 - 1 , KR 2 - 2 , KR 3 - 1  and KR 3 - 2  are closed, so that power output indicator V 3 , which is parallelly connected between the GFCI device load output end hot power line and neutral line, is lit, indicating that both the single phase, three line socket on the surface of the GFCI device and LOAD output end have power output. 
     If the GFCI device has come to the end of its life, normal electric current does not flow through inside solenoid coil (SOL)  26 , and its iron core will not act and will not move locking member  30  and the reset button will never be able to reset. Neither the single phase, three line socket on the surface of the GFCI device nor the load output end will have power output and reset indicator V 5  and power output indicator V 3  will not be lit. 
     When functions of the GFCI device are intact, after the GFCI device is properly connected to a power source, and after the reset button RESET is pressed, the LOAD end and the surface of the GFCI device have power outputs. The GFCI device works normally, as shown in  FIG. 7-3 . At this time, when a leakage current is generated inside the GFCI device, due to the fact that hot line HOT and neutral line WHITE both thread through the leakage current differential transformers L 1  and L 2  concurrently, the vector sum of the current in the lines that thread through the differential transformers L 1  and L 2  is not zero. The differential transformers immediately sense a voltage signal and provide a signal input into the control chip IC. A release control signal is output from pin  5  of the control chip IC to the gate of SCR V 4 . SCR V 4  is triggered and the positive pole and the negative pole conduct, causing node B on the positive pole of SCR V 4  to be at a low electric potential. At this time, switch KR- 4  is in a closed state, and nodes A and B are the same potential. Because the other end of coil SOL  26  is connected to the hot power line, both ends of coil SOL  26  will receive a voltage. Electric current flows through coil SOL  26  and generates a magnetic field. The iron core  42  is engaged, causing the mechanical tripping device of the GFCI device to act (locking member  30  moves), which causes the reset directional lock  35  of reset button  8  to thread out from locking member hole  31  of locking member  30 . Reset button  8  is released, cutting off power output from the GFCI device. As shown in  FIG. 7-1 , power output indicator V 3  goes out and reset indicator V 5  is lit. 
     In addition to manual simulation of a leakage current by pressing the test button TEST to detect whether the GFCI device has come to the end of its life, the GFCI device also incorporates a forcible mechanical release to cut off the power output. As shown in  FIG. 8-2 , when the test button  7  is pressed down to its first position, flexible metal switch pieces  46  and  47  comprising test switch KR- 5  come into contact to manually generate a simulated leakage current. If the GFCI device works normally with its protective features intact, the mechanical tripping device should act. That is, locking member  30  acts so that reset button  8  is released, cutting off power output of the GFCI device. If after test button  7  is pressed down from a static state to the first position, the mechanical tripping device does not act (as shown in  FIGS. 8-3  and  9 - 1 ), then the GFCI device has come to the end of its life. At this time, as shown in  FIGS. 8-4  and  9 - 2 , test button  7  may continue to be pressed down to a second position to forcibly cut off the power output of the GFCI device through a mechanical device. More specifically step  40 E of arm  40   a  is pressed on the two sides of the V shaped slot  37 -A, causing sliding block  37  to rotate around projections  37 -D protruding on its two sides and acting as rotating axles. Through the upwardly inclined handled  37 -C of release sliding block  37  that extends into hole  32  on locking member  30 , locking member  30  is pulled to move, so that locking slot  36  of reset directional lock  35  jumps out of hole  31  of locking member  30 , reset support piece  28 A and release  28  drop down at the same time and flexible power line input metal pieces  50  and  51  drop down at the same time. Moving contacts on power input metal pieces  50  and  51  are disconnected from fixed contacts on power output conductors  13  and  14 , respectively. Power output conductors  13  and  14  and power output ends  80  and  81  respectively connected to flexible metal pieces  20  and  21  are not energized. Since power output conductors  13  and  14  and power output ends  80  and  81  are not energized, output power from the GFCI device is removed. 
     When there is a need to detect whether functions of the GFCI device are normal, a user may also press test button TEST to cause the upper ends of flexible metal switches pieces  46  and  47  to come into contact and to become conducted, generating a simulated leakage current, to test whether the GFCI device has come to the end of its life. If the failure of the GFCI device is not eliminated, the mechanical tripping device cannot act, thus preventing the reset button RESET from being reset, and the GFCI device does not have a power output. 
     In these circumstances, the control signal from pin  5  of control chip IC must be filtered by anti-interference capacitor C 5  connected between the control end of the SCR V 4  and ground, to suppress any erroneous tripping of the GFCI device. 
     As shown in  FIGS. 11 ,  5  and  10 - 1  the GFCI device includes a red reset indicator V 5  (R) on circuit board  18  to indicate whether the GFCI device has come to the end of its life. A green or yellow power output indicator V 3  (G) is parallelly arranged with the reset indicator V 5  (blocked by reset indicator R in  FIG. 10-1 ), to indicate the working status of the GFCI device. The indicators V 3  and V 5  deflect the light emitted through light guide tube D onto the surface of the GFCI device, so that the indications are visible through status indicator hole  30 -A as shown in  FIG. 2 . When the power input end of the ground fault circuit interrupter is properly connected to the hot power line and neutral line inside the wall, as long as the ground fault circuit interrupter has not come to the end of its life and still has protective functions against a leakage current, reset indicator V 5  is lit; if the ground fault circuit interrupter has come to the end of its life, reset indicator V 5  is not lit. When ground fault circuit interrupter has not come to the end of its life and has power output, reset indicator V 5  goes out and power output indicator V 3  is lit; by contrast, when the ground fault circuit interrupter has come to the end of its life and has no power output, reset indicator V 5  is lit and power output indicator V 3  is not lit. Therefore, the user can determine whether the ground fault circuit interrupter has come to the end of its life and determined its work status by the status of indicators V 5  and V 3 . 
     Based on the above description, The herein disclosed GFCI device includes the following salient functions: 
     (1) After the power input end of the GFCI device is properly connected to a power supply, without operating any part, a simulated leakage current can be automatically generated to detect whether the GFCI device still protects functions against any leakage current, that is, whether the GFCI device has come to the end of its life. In addition, the results of this test can be displayed to a user. 
     When the internal components of the GFCI device are intact and reset indicator is lit, it indicates that a proper reset mechanism can be automatically set up and reset is possible. After a reset, the reset indicator is not lit and the power output indicator is lit, indicating that the GFCI device can work normally; 
     When the internal components of the GFCI device have an open or short circuit, that is, when they come to the end of their lives, the reset indicator does not come on, indicating that the GFCI device has come to the end of its life and preventing the reset button from being reset, thus, the GFCI device&#39;s load output end and the single phase, three line power output on the surface of the interrupter do not have any power output. 
     (2) When components inside the GFCI device, especially the solenoid coil, fail, that is when the device has come to the end of their lives, the GFCI device can be forcibly tripped/released by mechanical means, thus forcibly cutting off its power output and causing the ground fault circuit interrupter that has come to the end of its life not to be able to be reset. 
     (3) When an electric leakage current is generated by manual simulation and the GFCI device can be tripped/released, the reset indicator is lit, indicating that the GFCI device can work normally and can be reset. After the reset, the reset indicator goes out and the power output indicator is lit. When a leakage current is generated by manual simulation and the GFCI device cannot be tripped/released, the reset indicator is not lit, which indicates that the GFCI device has come to the end of its life. At this time the GFCI can be forcibly tripped/released by mechanical means. After it is tripped, the GFCI device can prevent the reset button from being reset, thus causing the load output end of the GFCI device and the single phase, three line power output on the surface of the GFCI device not to have power output. 
     (4) When an installer or electrician erroneously connects the power line inside the wall to the power output end of the GFCI device, as indicated in  FIG. 11  and  FIG. 12 , without operating any part, the GFCI device generate a leakage current that the circuit that generates simulated electric leakage current cannot generate. Electric leakage current detection chip IC cannot generate a control signal, SCR V 4  cannot conduct, no electric current flows through the solenoid coil SOL, no magnetic field can be generated to push its built-in iron core to act to disable the mechanical tripping apparatus, and the mechanical release apparatus cannot act, thus automatically preventing the reset button from being reset. The GFCI device does not have power output. The reset indicator is not lit, indicating a wiring error. It is only when the installer properly connects the lines that the reset indicator will be lit, the reset button can be reset and the power output end of the GFCI device will have power output. 
     The embodiments illustrated and discussed in this specification are intended only to teach those skilled in the art the best way known to the inventors to make and use the invention. Nothing in this specification should be considered as limiting the scope of the present invention. The above-described embodiments of the invention may be modified or varied, and elements added or omitted, without departing from the invention, as appreciated by those skilled in the art in light of the above teachings. It is therefore to be understood that, within the scope of the claims and their equivalents, the invention may be practiced otherwise than as specifically described.