This application claims the priority of Chinese Patent Application Nos. 200720005068.4, filed on Feb. 14, 2007 and 200720103644.9, filed on Feb. 15, 2007, which are herein incorporated by reference.
The present invention relates to a circuit interrupting device which comprises a novel reset mechanism to allow a user to test whether the device is wired properly. The novel reset mechanism includes a reset conducting apparatus which contains a reset start switch (KR-4). The KR-4 contains a first conducting pin, a second conducting pin, and a conducting bridge. When the reset button is depressed and the device is wired properly, the KR-4 is closed to allow the conducting bridge to be in contact with both the first and the second conducting pins so as to reset the device. The present invention also relates to a circuit interrupting device which is capable of automatically checking the components of the circuit interrupting device (i.e., the end of life test) through a novel status test switch (KR-1). The KR-1 comprises a flexible metal piece and a simulated leakage current controlling resistor, which is located underneath of the flexible metal piece. When the circuit interrupting device is properly wired and at a tripped state, without touching any parts of the circuiting interrupting device, the KR-1 is closed which generates a simulated leakage current to allow the device to conduct the end of life test. If all of the components in the device are functioned properly, a reset indicating light is lit.
Circuit interrupting devices, such as ground fault circuit interrupters (GFCIs), arc fault circuit interrupters (AFCIs), and circuit breakers, have been widely used by consumers since 1970s. Nowadays, due to household safety concerns, there are needs for GFCIs with extra safety features. According to new UL standards under 943A which was implemented on Jul. 28, 2006, a GFCI is required not only to have reverse wiring protection, but also to be able to provide a user with indications when the GFCI has reached the end of its service life and is no longer capable of providing ground fault protection, and cutoff electricity on the user accessible plug of the GFCI. That is because for most of the GFCIs currently available on the market, when their service life ends, resetting by pressing the reset button is still possible, which gives the users a false sense of security that they are still under proper protection of the GFCI, while in fact the GFCIs' capability of sensing a ground fault and cutting off the electricity due to a ground fault has been compromised. Thus, when a ground fault occurs, the GFCI is unable to provide any protection, which can result in fatal electric shocks. Additionally, current GFCIs do not have the capability to prevent reverse wiring errors. Additionally, current GFCIs do not have the capability to prevent reverse wiring errors.
The present invention provides a novel circuit interrupting device which is capable of establishing/disconnecting electrical continuity between a power source, an output load, and a user accessible load. The circuit interrupting device comprises a reset button and a reset conducting apparatus which comprises a reset start switch (KR-4) operationally connecting to the reset button so that when the circuit interrupting device is wired properly, a depression of the reset button allows the KR-4 switch to close.
The KR-4 comprises a first conducting pin, a second conducting pin, and a conducting bridge. The first conducting pin has a first end and a second end. The first end of the first conducting pin is adapted to electrically connect to ground via a silicon controlled rectifier (SCR). The second conducting pin has a first end and a second end. The first end of the second conducting pin is adapted to electrically connect to a hot wire at an input end of a power source via a solenoid coil. The second end of each of the first and the second conducting pins has an upper conducting piece and a lower conducting piece separated by a recessed slot. The conducting bridge can electrically connect to the first conducting pin and the second conducting pin by contacting with the upper conducting pieces or the lower conducting pieces of the first and second conducting pins.
The reset conducting apparatus is located at the bottom of a tripper, which is a part of the tripping device. The first and the second conducting pins are shaped like an “F.” The conducting bridge is rested at the recessed slot between the upper conducting piece and the lower conducting piece and not connected to the first and the second conducting pins when the circuit interrupting device is at a tripped state.
When the reset button is pressed, the conducting bridge is pressed against each of the lower conducting piece of the first and the second conducting pins.
Furthermore, the reset conducting apparatus further comprises a reset switch box having a spring receiving slot in the center. There is a directional spring located between the conducting bridge and the spring receiving slot of the reset switch box. When the reset button is depressed, the directional spring is compressed to allow the conducting bridge to press against each of the lower conducting piece of the first and second conducting pins. When the reset button and the tripper are in the released state, the conducting bridge is rested at the recessed slot between the upper conducting piece and the lower conducting piece. When the reset button is reset, the directional spring is relaxed which allows the conducting bridge to be contacted with each of the upper conducting piece of the first and second conducting pins.
The circuit interrupting device is a ground fault circuit interrupter, an arc fault circuit interrupter, an immersion detection circuit interrupter, an appliance leakage circuit interrupter, or a circuit breaker.
The circuit interrupting device further comprises a tripping device. The tripping device contains (1) a tripper which has an aperture to receive a directional lock extended from said reset button; (2) a locking device having a locking spring and containing a first through hole and a second through hole; the first through hole is capable of aligning with the aperture of the tripper to receive the directional lock extended from the reset button; and the locking device threads through said tripper; and (3) a solenoid coil (SOL) having a plunger. When the SOL is energized, the plunger plunges onto a side wall of the locking device causing the first through hole to align with the aperture of the tripper to reset or trip the circuit interrupting device so as to connect or disconnect the electrical continuity of the circuit interrupting device.
The second through hole of the locking device receives an upward inclined handle of a rotatable tripping lever. The rotatable tripping lever further comprises a pair of rotating shafts protruding on both sides of the rotatable tripping lever, a level axis, and a v-shaped slot capable of receiving an end of an arm extended from a test button.
The pair of the rotating shafts on the rotatable tripping lever are secured in a pair of vertical directional slots within a solenoid coil support.
The circuit interrupting device further comprises a pair of metal pieces which are situated along a side of the rotatable tripping lever in the solenoid coil support. This pair of metal pieces does not contact with each other when the rotatable tripping lever is not rotated. But when the rotatable tripping lever is rotated upward, the side of the rotatable tripping lever pushes the pair of the metal pieces to be in contact with each other. One of this pair of the metal pieces is adapted to electrically connect to a neutral wire at the input end of the power source via a resistor; and the other one of this pair of the metal pieces is adapted to electrically connect to a hot wire of an output end.
The circuit interrupting device has a test button, which has a first level and a second level of depression. When the test button is depressed at the first level, the end of the extended arm of the test button pushes the v-shaped slot of the rotatable tripping lever to cause the rotatable tripping lever to rotate around the lever axis and thereby pushes the pair of metal pieces to be in contact with each other, thereby simulated a fault to test components of the circuit interrupting device. A depression of the test button at the second level causes the circuit interrupting device to be mechanically tripped.
The components of the circuit interrupting device can be tested by the depression of the test button at the first level comprise a differential transformer (DT), an integrated circuit (IC), a silicon controlled rectifier (SCR), and a solenoid coil (SOL).
The circuit interrupting device further comprises a first pair of flexible metal pieces and a second pair of flexible metal pieces. One end of each of the first pair of the flexible metal pieces passes through a differential transformer and is operationally connected to a hot power input end or a neutral power input end. The other end of each of the first pair of the flexible metal pieces has a movable contact point. One end of each of the second pair of the flexible metal pieces is operationally connected to a hot power output end or a neutral power output end. The other end of each of the second pair of the flexible metal pieces has a movable contact point.
The circuit interrupting device further comprises a pair of output conductors connected to the user accessible load and positioned in the housing. Each of the output conductors contains a pair of fixed contact points. The movable contact point of each of the first pair of the flexible metal pieces and the movable contact point of each of the second pair of flexible metal pieces are capable of connecting/disconnecting to each of the fixed contact points of the pair of output conductors respectively. Each of the first pair of the flexible metal pieces and each of the second pair of the flexible metal pieces are soldered on a circuit board and are not directly connected to the input end and the output end. Also, each of the movable contact points of the first pair of the flexible metal pieces is in a different cross sectional plane from each of the movable contact points of the second pair of the flexible metal pieces. Furthermore, the first pair of the flexible metal pieces and the second pair of the flexible metal pieces are above a pair of cantilever arm at both sides of the tripper.
Each of the pair of the output conductor comprises a pair of gripping wing pieces protruded to output socket holes at a front lid of the housing.
When each of the movable contact point of each of the first pair of flexible metal pieces is connected to each of the fixed contact points of the pair of output conductors, electrical current is conducted from the power source to the user accessible load. When each of the movable contact point of each of the second pair of flexible metal pieces is connected to each of the fixed contact points of the pair of output conductors, electrical current is conducted from the user accessible load to the output load.
The circuit interrupting device further comprises a simulated leakage current controlling resistor, which is located underneath one of the first pair of flexible metal pieces that is adapted to electrically connected to a neutral wire of said input end. The simulated leakage current controlling resistor has a first end and a second end. The first end of the simulated leakage current controlling resistor is capable of contacting with one of the first pair of flexible metal pieces; the second end of the simulated leakage current controlling resistor is adapted to electrically connect to the hot wire of the input end via the solenoid coil (SOL). The simulated leakage current controlling resistor and one of the first pair of flexible metal pieces form a status test switch (KR-1).
When the circuit interrupting device is powered on and at a tripped state, the KR-1 is closed due to the simulated leakage current controlling resistor contacting with one of the first pair of flexible metal pieces. The KR-1 is closed without a depression of the reset button.
Also, when the circuit interrupting device is reset, the KR-1 is opened due to the separation of the simulated leakage current controlling resistor from one of the first pair of flexible metal pieces.
When the KR-1 is closed, the circuit interrupting device is automatically performing a test of the components of the circuit interrupting device.
The components of the circuit interrupting device that can be tested include, but are not limited to, a differential transformer, an integrated circuit, a silicon silicon controlled rectifier (SCR), and a solenoid coil.
The circuit interrupting device further contains a reset indicating light. One end of the reset indicating light is connected to a negative pole of the power source through the SCR and the other end is connected to the hot wire of the input end of said power source through a resistor and the solenoid coil. When all of the components function properly, a reset indicating light is lit. The circuit interrupting device further comprises a power output indicator light. When the circuit interrupting device has power output, the power output indicator light is lit.
There is a pair of hooked pins which is positioned above the first pair of flexible metal pieces. The pair of hooked pins has an upper end and a lower end; each of the upper end of the hooked pins is clamped to a mid-level support within the housing. Each of the lower end of the hooked pins has a cylindrical platform which is pressed on each of the pair of flexible metal pieces when the circuit interrupting device is powered on and at a tripped state to cause the simulated leakage current controlling resistor to be in close contact with one of the first pair of flexible metal pieces so as to generate a simulated leakage current. Each of the pair of hooked pins comprises a spring at outside of each of the pair of hooked pins.
The solenoid coil has a coil protection cover which is placed at outside of the solenoid coil.
The present invention also provides a circuit interrupting device which comprises a reset button; and a status test switch (KR-1) containing a flexible metal piece having a first end and a second end. The first end of the flexible metal piece is soldered to a circuit board. The second end of the flexible metal piece is capable of contacting a simulated leakage current controlling resistor located underneath the flexible metal piece. The flexible metal piece is adapted to electrically connected to a neutral wire of an input end of a power source.
The simulated leakage current controlling resistor has a first end and a second end. The first end of the simulated leakage current controlling resistor is capable of contacting the flexible metal piece. The second end of the simulated leakage current controlling resistor is adapted to connect to the circuit board and electrically connect to a hot wire of the input end via a solenoid coil.
When the flexible metal piece is adapted to electrically connect to the neutral wire of the input end, the simulated leakage current controlling resistor is adapted to electrically connect to the hot wire of the input end and vise versa.
When the circuit interrupting device is powered on and at a tripped state, without depressing the reset button, the flexible metal piece is in contact with the simulated leakage current controlling resistor so as to close the KR-1. When the circuit interrupting device is reset, the flexible metal piece is separated from the simulated leakage current controlling resistor to open the KR-1.
Also, when the KR-1 is closed, the flexible metal piece, the simulated leakage current controlling resistor and the solenoid coil form a loop to automatically generate a simulated leakage current to test components of the circuit interrupting device without a depression of the reset button.
The components of the circuit interrupting device that can be tested by the simulated leakage current include, but are not limited to, a differential transformer, an integrated circuit, a silicon controlled rectifier (SCR), and a solenoid coil.
When all of the components of the circuit interrupting device are functioned properly, a reset indicating light is lit.
The detailed description will refer to the following drawings in which like numerals refer to like elements, and in which:
The present invention describes a circuit interrupting device, which includes, but is not limited to, a ground fault circuit interrupter (GFCI), an arc fault circuit interrupter (AFCI), an immersion detection circuit interrupter, an appliance leakage circuit interrupter, or a circuit breaker. The preferred circuit interrupting device is a GFCI.
The following experimental designs and result are illustrative, but not limiting the scope of the present invention. Reasonable variations, such as those occur to reasonable artisan, can be made herein without departing from the scope of the present invention. For example, while an exemplary GFCI is illustrated and described with respect to the Figures, one skilled in the art will appreciate that the description equally applies to other circuit interrupting devices. Also, in describing the invention, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected. It is to be understood that each specific element includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
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The metal mounting strap 1 is grounded through a grounding screw 13-A (as shown in
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The circuit board 18, which is installed inside the housing, is capable of supplying power to or cutting off power from the power output sockets 5, 6 of the front lid 2 and the power output wiring screws 109, 110. The circuit board 18 is also capable of automatically checking for component failure, setting up a corrective reset mechanism upon power-on, and preventing reverse wiring errors.
A movable contact 54 is located on the opposite end of the flexible neutral power input metal piece 50. A movable contact 55 is located on the opposite end of the flexible hot power input metal piece 51. The movable contacts 54, 55 respectively correspond to fixed contacts 52, 53 on the power output conductors 13, 14 located on the insulated mid-level support 3 (as shown in
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The tripper 28 may have a cylindrical body and is located below the reset button 8. The left side and the right side of the tripper 28 extend outwardly to form lifting arms. The flexible power input metal pieces 50, 51 and the flexible power output metal pieces 20, 21 are located on the upper part of the lifting arms on both sides of the tripper 28 and can move up and down with the tripper 28. As shown in
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A circular recessed locking slot 36 is formed in the lower part of the reset directional lock 35 close to the bottom of the reset directional lock 35 to form a groove. A movable “L”-shaped locking member 30 made of a metal material is arranged in the lower part of tripper 28 and penetrates through the tripper 28. A through hole 31 is formed on the horizontal side of the locking member 30. The locking member 30 is movable in a horizontal direction between an aligned position (in which the through hole 31 of the locking member 30 is aligned with the blunt end of the rest directional lock 35 to allow the rest directional lock 35 to pass through) and a misaligned position (in which the circular recess locking slot 36 of the directional lock 35 is locked into the through hole 31 of the locking member 30). A circular slot 33 is formed between the side wall of tripper 28 and the inner side of the locking member 30. The locking spring 34 is arranged in the circular slot 33. The solenoid coil 26 with a built-in movable iron core 42 is arranged outside of the side wall of the locking member 30. The movable iron core 42 inside the solenoid coil 26 faces the side wall of the locking member 30. Locking member 30 can move when forced by iron core 42, causing reset button 8 to reset or release (trip). A spring 42A is inserted on a section of iron core 42, as shown. A protective shield 41 is arranged above the solenoid coil 26. One end of the insulated mid-level support 3 presses against the protective shield 41.
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The two “F” shaped conducting pins 66 and 67 may be positioned on opposite sides of the reset switch box 65. The “F” shaped pins 66 and 67 comprise upper conducting pieces 66-A and 67-A, center recessed slots 66-C and 67-C, and lower conducting pieces 66-B and 67-C. A lower end of one of the “F” shaped conducting pin 67 is connected to the grounding power line through a silicon controlled rectifier V5. The lower end of the other “F” shaped conducting pin 66 is connected to the hot power line of the alternating power input end through solenoid coil 26 (as shown in
The reset conducting apparatus 65-A also includes a conducting bridge 72, which is positioned within the reset switch box 65. The conducting bridge 72 may be positioned between the recessed slots 66-C and 67-C of the two “F” shaped conducting pins 66 and 67. The conducting bridge 72 includes a first pair of contact legs 68 and a second pair of contact legs 69 extending from the conducting bridge 72. The conducting bridge 72 may rest on a directional spring 71 positioned inside the reset switch box 65, in a circular plate slot used to fix directional spring 71. As shown in
The reset conducting apparatus 65-A constitutes a reset start switch KR-4, shown in
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Therefore, the present invention indicates the status of reset button 8 through the reset conducting apparatus 65-A (i.e., reset start switch KR-4). When contact legs 68 and 69 on the two sides of conducting bridge 72 formed by the sides bending downward respectively are in recessed slot 66-C and 67-C between conducting pins 66 and 67, when reset button 8 is in a released state. When contact legs 68 and 69 on the two sides of conducting bridge 72 formed by the sides bending downward respectively come into contact with lower conducting pieces 66-B and 67-B of reset conducting pins 66 and 67 and become on, which demonstrates that reset button 8 is pressed. When the upper surfaces of contact legs 68 and 69 on the two sides of conducting bridge 72 come into contact with upper conducting pieces 66-A and 67-A of conducting pins 66 and 67 and become on, reset button 8 is in a reset state.
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As long as the power input end hot power line 51 and neutral power line 50 of the GFCI are properly connected to the hot power line and the neutral power line inside the wall, the power input end neutral power line 50 is connected to the hot power line 51 on the circuit board 18 through flexible neutral power line input metal piece 50, simulated leakage current controlling resistor R88, and the solenoid coil 26, forming a loop capable of automatically generating simulated leakage current without the need to operate any part.
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The upper ends of the spring pieces 46 and 47 are open. When the test button 7 is not pressed, since the rotatable tripping lever 37 is not rotating, the upper ends of the spring pieces 46 and 47 do not come into contact. The lower end of the spring piece 46 is soldered onto the printed circuit board 18 and is connected to the neutral wire of the power input end through a resistor (R3 in
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The tripper 28, the locking member 30, the locking spring 34, the rotatable tripping lever 37, and the reset start switch KR-4 are connected to each other to form an integral body that can move freely.
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When reset button 8 is in a released state, as long as power input end wiring screws 9 and 10 of the ground fault circuit interrupter are properly connected to the neutral power line and hot power line inside the wall, the end of simulated leakage current controlling resistor R88 will come into contact with flexible neutral power input metal piece 50 and leakage current simulation switch KR-1 is closed. The power input end neutral power line is connected to the hot power line through flexible neutral power line input metal piece 50, simulated leakage current controlling resistor R88 and solenoid coil 26, forming a loop capable of automatically generating simulated leakage current without the need to operate any part. When reset button 8 is in a released state, conducting bridge 72 is in recessed slot positions 66-C and 67-C in the middle of conducting pin 66 and 67 (as shown in
The hot wire and neutral wire on the power supply line for the GFCI penetrate through the differential transformers L1 and L2. The signal output ends of the differential transformers L1 and L2 are connected to the signal input ends 2, 3 and 5 of the leakage detection control chip IC (LM1851) or the signal input ends 1, 2, 3, 7 of the leakage detection control chip IC (RC4145). The control signal output pin 1 of the leakage detection control chip IC (LM1851) or the control signal output pin 5 of the leakage detection control chip IC (RC4145) is connected to the gate of the silicon controlled rectifier V5. The negative pole of the silicon controlled rectifier V5 is connected to the negative pole of the direct current power supply, and the positive pole of the silicon controlled rectifier V5 is connected to the hot wire through the reset start switch KR-4 coupled to the reset button and the solenoid coil 26. The built-in plunger of the solenoid coil causes the reset button to reset or release through a mechanical tripping device, thus causing the switches KR-2-1, KR-2-2, KR-3-1, KR-3-2 coupled to the reset button to close or disconnect, respectively.
The power output indicator V7 is connected between the hot wire and the neutral wire of the power output ends of the GFCI. The reset indicating light V6 is serially connected to the silicon controlled rectifier V5.
The output indicator V7 turns “on” when the GFCI has output power output. Otherwise, output indicator V7 does not turn “on.”
Reset indicating light V6 is serially connected on the loop of silicon controlled rectifier V5. One end of reset indicating light V6 is connected to the negative direct current power supply through silicon controlled rectifier V5, and the other end is connected to the hot power line of the power input end through resistor R4 and solenoid coil 26. When the leakage current protection circuit works normally, and components that comprise the leakage current protection circuit, such as silicon controlled rectifier V5, solenoid coil 26 and differential transformers L1 and L2 are intact and silicon controlled rectifier V5 is intact and can come on normally, reset indicating light V6 turns “on,” indicating that the ground fault circuit interrupter has protective functions against a leakage current. In contrast, in the event that components of the leakage current protection circuit fail, causing the leakage protection circuit to come to the end of its life, reset indicating light V6 is not turned “on,” indicating that the leakage protection circuit has come to the end of its life and remaining the user that it is time to promptly replace it with a new product.
The power input end neutral line penetrates through detection coils L1 (200:1) and L2 (1000:1) and is connected to the power input end hot line through the status test switch KR-1, the current limiting resistor R88, and the solenoid coil 26, forming a simulated leakage current loop. This circuit makes it possible for the power input end of the GFCI to automatically generate a simulated leakage current after it is properly connected to the power line inside the wall.
After the power input end of the GFCI is properly connected to the power line inside the wall and when the reset button is not depressed, since the status test switch KR-1 is in a closed state, the aforementioned simulated leakage current loop circuit automatically generates a simulated leakage current. As shown in
The silicon controlled rectifier V5 is triggered, and the positive pole and the negative pole are turned on. The reset indicating light V6 connected on the indicator circuit between A and B emits light, indicating that the functions of the GFCI are intact and have protective functions against electric leakage current, and that the reset button can be reset. In contrast, if the GFCI has come to the end of its life, then the reset indicating light V6 will never emit any light. The silicon controlled rectifier V5 will not come on and no electric current will ever flow through the solenoid coil 26, rendering it unable to generate a magnetic field. The internal plunger inside the solenoid coil 26 does not move and the mechanical tripping device will not move. The reset button cannot be reset, thus reminding the user that the GFCI has come to the end of its life and should be replaced with a new GFCI. Therefore, after the power input end is properly connected to the power line inside the wall, the GFCI automatically performs a test on the GFCI to ascertain whether the GFCI still has any protective functions against electric leakage current, i.e., whether it has come to the end of its life. The test result is automatically displayed to the user.
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When the GFCI is functioned properly, after the GFCI is properly connected to the power line and after the reset button is pressed, the load output end and the surface of the GFCI have power output. The GFCI works normally (as shown in
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Pressing the test button 7 may manually simulate an electric leakage current to detect whether the GFCI has come to the end of its life. Continually pressing the test button 7 may forcibly and mechanically cut off the power output of the GFCI. As shown in
The upper ends of the spring pieces 46 and 47 are open. When the test button 7 is not pressed, since the rotatable tripping lever 37 is not rotating, the upper ends of the spring pieces 46 and 47 do not come into contact. The lower end of the spring piece 46 is soldered onto the printed circuit board 18 and is connected to the neutral wire of the power input end through a resistor (R3 in
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If pressing the test button 7 from a static state to the first position to generate the electric leakage current will not trip the GFCI, this indicates that the GFCI has come to the end of its life. As shown in
When there is a need to test whether functions of the GFCI are normal, a user may also press the test button 7 to cause the upper ends of spring pieces 46, 47 to come into contact, generating a simulated leakage current. If the GFCI works normally and has not come to the end of its life, the differential transformer will detect a voltage signal and output the voltage signal to the signal input ends 2, 3, 5 of the leakage detection control chip IC. Pin 1 of the leakage detection control chip IC outputs an electric leakage current trigger signal, which is output to the gate of the silicon controlled rectifier V5, so that the silicon controlled rectifier V5 is triggered and turned on, and the circuit interrupting device is tripped. Since at the reset start switch KR-4 is open, an electric current path is formed from the hot wire through the solenoid coil 26, the resistor R4, the reset indicating light V6, and the silicon controlled rectifier V5 to the grounding terminal. The reset indicating light V6 is on, indicating that the functions of the GFCI are functioned properly and the GFCI can be reset. When the GFCI has come to the end of its life, a failure of the internal components may interrupt the electric leakage current detection functions. Pin 1 of the leakage detection control chip IC does not have any control signal output, and the silicon controlled rectifier V5 cannot be triggered. The reset indicating light V6 is off, and the solenoid coil 26, after the power output of the GFCI being forcibly cut off, cannot be energized. Therefore, pressing the reset button 8 cannot complete the reset. This indicates that the GFCI has experienced an internal failure. In other words, the GFCI has come to the end of its life and should be promptly replaced.
If the failure of the GFCI is not eliminated, the mechanical tripping device cannot function. The GFCI does not have power output.
In the circumstances above, the control signal from pin 1 of the leakage detection control chip IC passes through and filters by an anti-interference capacitor C7 between the control end of the silicon controlled rectifier V5 and the grounding terminal to prevent any unintentional triggering.
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Based on the above description, since the present invention uses the above technical solution, the GFCI disclosed by the present invention has the following functions:
(1) After the power input end of the GFCI is properly connected to the power line inside the wall, a simulated leakage current can be automatically generated to detect whether the GFCI still has protective functions against any electric leakage current, that is, whether it has come to the end of its life. The result is automatically displayed.
When the internal components of the GFCI are intact and the reset indicating light is constantly on, it indicates that a proper reset mechanism can be automatically set up and reset is possible. After a reset, the reset indicating light off and the power output indicating light is constantly on, indicating that the GFCI can work normally.
When the internal components of the GFCI have an open or short circuit, that is, when they come to the end of their lives, the reset indicating light does not come on, indicating that the GFCI has come to the end of its life. The reset button cannot be reset, thus, and the GFCI's output end and the power output sockets on the surface of the GFCI do not have any power output.
(2) The GFCI has mechanical release capabilities.
When components inside the GFCI do not function, especially when the solenoid coil fails, the GFCI can be forcibly tripped or released by mechanical means, thus forcibly cutting off its power output. As a result the GFCI that has come to the end of its life cannot be reset.
(3) The GFCI has manual detection capabilities and can automatically display the detection result.
When an electric leakage current is generated by manual simulation and the GFCI can be tripped or released, the reset indicating light is constantly on, indicating that the GFCI can work normally and can be reset. After the reset, the power output indicator is constantly on.
When an electric leakage current is generated by manual simulation and the GFCI cannot be tripped or released, the reset indicating light is off, indicating that the GFCI has come to the end of its life. The present invention can prevent the reset button from being reset, thus causing the power output socket on the surface of the GFCI and the load output end not to have power output.
(4) The GFCI can prevent reverse wiring errors.
When an electrician erroneously connects the power line inside the wall to the power output end of the GFCI, the present invention can automatically prevent the generation a simulated leakage current. The electric leakage current detection chip IC cannot generate a control signal, the silicon controlled rectifier V5 cannot be turned on, no electric current flows through inside the solenoid coil, no magnetic field can be generated to push its built-in plunger to move to disable the mechanical tripping device, the reset button can never be reset and the switches KR-3-1, KR-2-1, KR-3-2, KR-2-2 coupled to the reset button cannot be closed. The power input end of the GFCI “LINE” and the power output sockets on the surface of the GFCI do not have power output. The reset indicating light V6 is off, indicating a wiring error. It is only when the installer properly connects the lines that the reset indicating light V6 will be on, the reset button can be reset, and the power output end of the GFCI and the power output sockets on the surface of the GFCI have power output.
The exemplary GFCI can be widely applied, is safe and easy to use, thus effectively ensuring the personal safety of the user as well as the safety of appliances.
While the GFCI with an automatic end-of-life test has been described in connection with an exemplary embodiment, those skilled in the art will understand that many modifications in light of these teachings are possible, and this application is intended to cover variations thereof. Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications.
Number | Date | Country | Kind |
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200720005068.4 | Feb 2007 | CN | national |
200720103644.9 | Feb 2007 | CN | national |