Abstract:
An electrical wiring device including: a housing, a plurality of line terminals, feed-through load terminals and receptacle load terminals electrically connected to a pivotable contact structure or to a fixed contact structure comprising a conductive member having at least one contact positioned thereon, wherein in response to a make-force each pivotable contact structure is configured to perform a first pivotable movement to electrically connect each of the contacts on each pivotable contact structure to one of the contacts on a different one of the fixed contact structures in the reset state, thereby electrically connecting the terminals in the reset state; a circuit interrupting assembly including at least one breaking element being configured to perform a first linear movement in a first direction in response to a break-force in order to cause each pivotable contact structure to perform a second pivotable movement in a direction opposite the first pivotable movement to decouple each of the contacts on each pivotable contact structure from one of the contacts on a different one of the fixed contact structures thereby decoupling the terminals to effect a tripped state; and a protective electrical assembly.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a continuation of U.S. patent application Ser. No. 15/141,176, filed on Apr. 28, 2016, which is a continuation of U.S. patent application Ser. No. 15/081,429, filed on Mar. 25, 2016, which is a continuation of U.S. patent application Ser. No. 14/139,052, filed on Dec. 23, 2013, which is a continuation of U.S. patent application Ser. No. 13/902,497 filed on May 24, 2013, which is a continuation of U.S. patent application Ser. No. 13/023,575, filed on Feb. 9, 2011, which is a continuation of U.S. patent application Ser. No. 12/619,027, filed on Nov. 16, 2009, which is a continuation of U.S. patent application Ser. No. 12/415,217, filed on Mar. 31, 2009, which is a continuation of U.S. patent application Ser. No. 10/953,805 filed on Sep. 29, 2004, the contents of which are relied upon and incorporated herein by reference in their respective entireties, and the benefit of priority under 35 U.S.C. §120 is hereby claimed. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention relates to the field of circuit protective devices, and in particular, to a circuit protection device having a relatively thin construction. 
         [0004]    2. Technical Background 
         [0005]    The demand for electrical power is insatiable because of the increased reliance on electricity for everyday needs. Power is provided to electricity users by way of electrical distribution systems that typically include electrical wiring from a utility power source to a breaker panel disposed in a house, building or some other facility. The breaker panel distributes AC power to one or more branch electric circuits installed in the structure. The electric circuits may typically include one or more receptacle outlets and may further transmit AC power to one or more electrically powered devices, commonly referred to in the art as load circuits. The receptacle outlets provide power to user-accessible loads that include a power cord and plug, the plug being insertable into the receptacle outlet. However, certain types of faults have been known to occur in electrical wiring systems. Accordingly, each electric circuit typically employs one or more electric circuit protection devices. 
         [0006]    Both receptacle devices and electric circuit protective devices are disposed in an electrically non-conductive housing. The housing also includes electrical terminals that are electrically insulated from each other. The terminals provide a means for connecting the device to the source of AC power and a means for connecting the device to a load. In particular, line terminals couple the device to the source of AC electrical power, whereas load terminals couple power to the load. Of course, those of ordinary skill in the art will understand that the term “load” may refer to an appliance, a switch, or some other device. Load terminals may also be referred to as “feed-through” or “downstream” terminals because the wires connected to these terminals may be coupled to a daisy-chained configuration of receptacles or switches. The load may ultimately be connected at the far end of this arrangement. Referring back to the device housing, the load terminals may be connected to an electrically conductive path that is also connected to a set of receptacle contacts. The receptacle contacts are in communication with receptacle openings disposed on the face of the housing. This arrangement allows a user to insert an appliance plug into the receptacle opening to thereby energize the device. 
         [0007]    With regard to installation, protective devices are commonly installed in outlets boxes. An outlet box may be located in a wall, ceiling, floor, counter-top, or the like. An electrical cable is placed from the breaker panel to the outlet box to provide the line terminals with AC power. The cable typically includes a plurality of insulated electrical conductors. Cables may be bundled together using a rigid or flexible tube made out of metal and/or electrically non-conductive material. A second cable of similar composition to the first cable is placed between the outlet box and any subsequent devices in the daisy-chain arrangement referred to above. The second cable, of course, is connected to the feed-through terminals. During installation of the outlet box, the cables are fed through openings in the outlet box for connection to their respective terminals, i.e., line or load. After the electrical conductors have been connected, the protective device is inserted into the front opening of the outlet box until the strap and a mounting surface in the outlet box mate. 
         [0008]    One of the problems associated with device installation relates to the limited interior volume in an outlet box. When the protective device is inserted into the outlet box, the wires, cables and associated tubing disposed inside the outlet box must necessarily be compressed within the space formed between the back side of the device and the interior wall of the outlet box. This may lead to a number of adverse and undesirable results. 
         [0009]    When an installer jams the device and the wires into the outlet box, the insertion force may cause the strap or some other member of the outlet box or protective device to deform. The deformation may interfere with the installation of the plate, or may prevent the protective device from fully coupling to the mounting surface of the outlet box. The deformation may also damage the protective device. As a result, the protective device may not function. Furthermore, the wire insulation may be urged against sharp interior edges of the outlet box or exterior edges of the protective device causing the conductors to become exposed. If the insulation loses its integrity, the electrical conductors may short together, or may short to the outlet box. Compression may also cause the insulation to split if the conductor becomes compressed within a tight bending radius. On the other hand, while any given electrical terminal is configured to grip electrical conductors with a securing force, the compression may apply an opposing force that results in loss of the intended electrical connection. 
         [0010]    The above described adverse effects are dependent on the random motions of the electrical conductors while the protective device is being inserted in the outlet box. The chance occurrence of an adverse effect is aggravated by the fact that the compressed wires cannot be seen by the installer because they are hidden from view as the device is being inserted into the outlet box. 
         [0011]    The problems described above are being exacerbated by the changes to wiring and installation practices that have occurred in recent years. The number of outlet box locations that require protection has expanded in the various commercial, institutional and residential sectors. Considering the residential sector, GFCIs were originally required to protect receptacles in the vicinity of outdoor swimming pools and have progressively been required to protect bathrooms, kitchens, basements and outdoor receptacles. More recently, AFCIs have been required to protect bedroom receptacles. The proliferation of installed locations increases the likelihood of such problems occurring. 
         [0012]    At the same time, there has been a reduction in the thickness of the wall stud and sheetrock used to construct walls. This has necessitated the use of shallower outlet boxes. Unfortunately, the shallower outlet box provides less volume for the electrical conductors inside the outlet box, causing an increase in the compression forces on the electrical conductors. This development is further exacerbated by the increased use of multiple cables in the outlet box. The additional cables are needed for the redundant line and/or feed-thru terminals often included in the protective device. 
         [0013]    In the residential market, the average square footage of new residences has been ever increasing. New residences typically include more built-in appliances than do older homes. As such, an increased amount of electric current must be propagated over larger distances. Accordingly, electrical conductors of greater cross section are required to conduct the greater current over a greater distance. Obviously, the consequence of multiple cables or electrical conductors of greater cross section is an increased probability of a problem occurring during installation. 
         [0014]    Another problem occurs when new protective devices are used to replace older non-protective wiring devices in older homes. Note that the electrical conductors may be original to the house. The insulation associated with the original conductors may be weakened through aging. This may result in an older installation being more susceptible to one or more adverse effects described above. 
         [0015]    All of the aforementioned trends lead to smaller outlet boxes. Accordingly, a decrease in the size of the protective device would be quite desirable. However, this is problematic because the necessary functionality that modern devices must possess is driver toward larger devices. To illustrate this point, a short survey of modern protective devices is provided below. 
         [0016]    As noted above, there are several types of electric circuit protection devices. For example, such devices include ground fault circuit interrupters (GFCIs), ground-fault equipment protectors (GFEPs), and arc fault circuit interrupters (AFCIs). This list includes representative examples and is not meant to be exhaustive. Some devices include both GFCIs and AFCIs. As their names suggest, arc fault circuit interrupters (AFCIs), ground-fault equipment protectors (GFEPs) and ground fault circuit interrupters (GFCIs) perform different functions. 
         [0017]    An arc fault is a discharge of electricity between two or more conductors. An arc fault may be caused by damaged insulation on the hot line conductor or neutral line conductor, or on both the hot line conductor and the neutral line conductor. The damaged insulation may cause a low power arc between the two conductors and a fire may result. An arc fault typically manifests itself as a high frequency current signal. Accordingly, an AFCI may be configured to detect various high frequency signals and de-energize the electrical circuit in response thereto. 
         [0018]    Ground fault circuit equipment protectors (GFEPs) and ground fault circuit interrupters (GFCIs), on the other hand, are used to detect ground faults. A ground fault occurs when a current carrying (hot) conductor creates an unintended current path to ground. A differential current is created between the hot/neutral conductors because some of the current flowing in the circuit is diverted into the unintended current path. The unintended current path represents an electrical shock hazard. Ground faults, as well as arc faults, may also result in fire. GFCIs intended to prevent fire have been called ground-fault equipment protectors (GFEPs). 
         [0019]    In addition to detecting arc faults and/or ground faults, a protective device itself must be protected from transient voltages and other surge phenomena. Transient voltages may be generated in a number of ways. For example, transient voltages may be generated by lightning storms. Transient voltages may also be produced when an inductive load coupled to the electrical distribution system is turned off, or by a motor coupled to the electrical distribution system that includes commutators and brushes. Whatever the cause, transient voltages are known to damage a protective device/cause an end of life condition. The damage may result in the protective device permanently denying power to the protected portion of the electric circuit. Consequently, the user suffers an expense and inconvenience of having to replace the protection device. Alternatively, the damage may result in the protection device becoming non-protective while continuing to provide power to the load circuit. The user can decide to keep using the device even though protection is not being afforded. Thus, damage of either type is not desirable. Accordingly, transient voltage tests are included in Underwriters Laboratories requirements for protective devices (e.g., UL standard 943 for GFCIs and UL standard 1699 for AFCIs). The protection device must continue to operate following these tests. 
         [0020]    To meet the UL requirements, metal oxide varistors (MOVs) are typically employed. MOVs clamp the transient voltage imposed on the line (or load) terminals of the protection device to a safe voltage, i.e., a magnitude of typically not more than twice the phase voltage. One drawback to using MOVs relates to the fact that they are bulky and expensive. UL has recently promulgated new surge voltage requirements for GFCIs and AFCIs that test the protective device&#39;s ability to provide protection following exposure to harsher surge energy levels. The new requirement is typically met by including a larger MOV which is adept at absorbing the higher energy voltage impulses. The protective device may include other surge protection components. In addition to MOVs, other surge protective components such as transient voltage surge suppressors (TVSS), spark gaps, and other such devices may be used. These components are not meant to be an exhaustive list. 
         [0021]    Of course, the circuitry used to implement a GFCI or an AFCI may typically include a sensor, such as a transformer, a solenoid, an SCR device, and other components disposed on a printed circuit board. The AFCI is a more recent protective device technology, similar to GFCI technology but typically having a detector that includes a greater number of electronic components that occupy more space. Those skilled in the art will recognize that there are different types of arc fault conditions, exemplified by a number of UL test conditions. There is a desire for a single protective device that passes as many of the arc fault test requirements as possible. There is also an increasing interest in combining two or more of a GFCI, TVSS, and AFCI in the protective device. 
         [0022]    For these and other like reasons, there has been an increase in the volume of the protective device&#39;s housing in order to meet new requirements. On the other hand, because of all of the trends discussed above, including the decrease in size of wall studs and wall board, the size of the outlet box has decreased as well. Unfortunately, the available volume inside the outlet box for the electrical wiring is reduced accordingly. This reduction in available volume results in greater susceptibility to one or more of the installation problems described above. 
         [0023]    What is needed is a smaller protective device that provides all of the protective safety features currently provided by larger devices. It is further desirable to provide a protective device having a width behind the strap of less than one inch. 
       SUMMARY OF THE INVENTION 
       [0024]    The present invention addresses all of the needs articulated above by engineering both the interior components and the arrangement of interior components to provide a smaller protective device that provides all of the protective safety features currently provided by larger devices. In fact, substantially all of the protective circuit assembly may be disposed in approximately one-half of the device such that the remaining half of the device interior may be employed by other additional functions. 
         [0025]    One aspect of the present invention is directed to a compact electrical wiring device that includes a housing having a front cover member, a back cover member and an electrical isolating member disposed between the front cover member and the back cover member such that a front interior region is formed between the front cover member and the electrical isolating member and a rear interior region is formed between the back cover member and the electrically isolating member. The electrical isolating member includes a plurality of electrical isolation compartments that are accessible via the front interior region and protrude into the rear interior region, the plurality of electrical isolation compartments including at least one ground contact compartment. A plurality of user-accessible terminals and a ground plate are disposed on the electrical isolating member in the front interior region and are accessible via the front cover member. A printed circuit board (PCB) assembly is disposed in the rear interior region, the PCB assembly is coupled to a plurality of line terminals and a plurality of load terminals that are accessible via an exterior of the housing. The PCB assembly includes a first PCB surface that faces the back cover member. The first PCB surface includes a circuit arrangement comprising a plurality of electronic components. The PCB assembly also includes a second PCB surface that faces the electrical isolating member and includes a toroidal fault sensor coupled to the plurality of line terminals, a solenoid actuator coupled to the circuit arrangement, and a circuit interrupter configured to movably engage the plurality of user-accessible terminals to provide electrical continuity between the plurality of line terminals, the plurality of load terminals and the plurality of receptacle contact structures in a reset state and movably disengage the plurality of user-accessible terminals to interrupt the electrical continuity to effect a tripped state. The toroidal fault sensor, the solenoid actuator, the circuit interrupter and the plurality of electrical isolation compartments are nested within the rear interior region such that a distance from the ground plate to the back cover member is less than or equal to about one inch. 
         [0026]    Another aspect of the present invention is directed to an electrical wiring device that includes a compact electrical wiring device that has a housing including a front cover member, a back cover member and an electrical isolating member disposed between the front cover member and the back cover member such that a front interior region is formed between the front cover member and the electrical isolating member and a rear interior region is formed between the back cover member and the electrical isolating member. A plurality of user-accessible terminals and a ground plate are disposed on the electrical isolating member in the front interior region and accessible via the front cover member. A toroidal fault sensor is disposed in the rear interior region and coupled to the plurality of line terminals. A protective circuit arrangement is disposed in the rear interior region and coupled to the toroidal sensor. A solenoid actuator is coupled to protective circuit arrangement. A circuit interrupter assembly is coupled to the solenoid actuator and configured to move along an assembly axis in a direction normal to a major surface of the electrical isolation member to provide electrical continuity between the plurality of line terminals, the plurality of load terminals and the plurality of receptacle contact structures in a reset state and to interrupt the electrical continuity to effect a tripped state, the circuit interrupter assembly including at least one portion configured to pivot relative to the assembly axis to effect the reset state or the tripped state, and wherein the toroidal fault sensor, the solenoid actuator, the circuit interrupter assembly and the plurality of electrical isolation compartments are nested within the rear interior region such that a distance from the ground plate to the back cover member is less than one inch. 
         [0027]    A further aspect of the present invention is directed to an electrical wiring device including a housing including a front cover having a front major surface and a back body having a back major surface substantially parallel to the front major surface, a plurality of line terminals, a plurality of feed-through load terminals and a plurality of receptacle load terminals at least partially disposed inside the housing, wherein each of the plurality of line terminals, the plurality of feed-through load terminals and the plurality of receptacle load terminals is electrically connected to a pivotable contact structure or to a fixed contact structure comprising a conductive member having at least one contact positioned thereon, wherein in response to a make-force each pivotable contact structure is configured to perform a first pivotable movement about a separate pivot point to electrically connect each of the contacts on each pivotable contact structure to one of the contacts on a different one of the fixed contact structures in the reset state, thereby electrically connecting the plurality of line terminals, the plurality of feed-through load terminals and the plurality of receptacle load terminals in the reset state; a circuit interrupting assembly including at least one breaking element at least partially disposed inside the housing and being configured to perform a first linear movement in a first direction, wherein the first linear movement is normal to the front major surface, and the first direction is from the front major surface to the back major surface, in response to a break-force in order to cause each pivotable contact structure to perform a second pivotable movement about the separate pivot point in a direction opposite the first pivotable movement to decouple each of the contacts on each pivotable contact structure from one of the contacts on a different one of the fixed contact structures thereby decoupling the plurality of line terminals, the plurality of feed-through load terminals and the plurality of receptacle load terminals from each other to effect a tripped state from the reset state; and a protective electrical assembly substantially disposed inside the housing, the protective electrical assembly including a sensor assembly coupled between the plurality of line terminals and a fault detection circuit, the fault detection circuit being coupled to a solenoid assembly configured to provide a tripping stimulus, the solenoid assembly including a bobbin winding and the sensor assembly including at least one toroid. 
         [0028]    Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein, including the detailed description which follows, the claims, as well as the appended drawings. 
         [0029]    It is to be understood that both the foregoing general description and the following detailed description are merely exemplary of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments of the invention and together with the description serve to explain the principles and operation of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]      FIG. 1  is a circuit diagram of a thin electrical wiring device in accordance with a first embodiment of the present invention; 
           [0031]      FIG. 2  is a cross-sectional view of a thin electrical device in accordance with the present invention; 
           [0032]      FIG. 3  is a longitudinal cross sectional view of a thin electrical wiring device in accordance with another embodiment of the present invention; 
           [0033]      FIG. 4  is a latitudinal cross sectional view of a thin electrical wiring device in accordance with yet another embodiment of the present invention; 
           [0034]      FIG. 5  is a detail view of the cover with a night light feature; 
           [0035]      FIG. 6  is a detail view of the cover with a switch; 
           [0036]      FIG. 7  is a diagrammatic depiction of a circuit interrupter in accordance with an embodiment of the present invention; 
           [0037]      FIG. 8  is a diagrammatic depiction of a circuit interrupter in accordance with another embodiment of the present invention; 
           [0038]      FIG. 9  is a diagrammatic depiction of a circuit interrupter in accordance with another embodiment of the present invention; 
           [0039]      FIG. 10  is a diagrammatic depiction of a circuit interrupter in accordance with yet another embodiment of the present invention; 
           [0040]      FIG. 11  is a diagrammatic depiction of a circuit interrupter in accordance with yet another embodiment of the present invention; 
           [0041]      FIGS. 12-15  are detail views of a reset lock-out mechanism; and 
           [0042]      FIG. 16  is a schematic diagram in accordance with an alternate embodiment is depicted. 
       
    
    
     DETAILED DESCRIPTION 
       [0043]    Reference will now be made in detail to the present exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. An exemplary embodiment of the protective wiring device of the present invention is shown in  FIG. 1 , and is designated generally throughout by reference numeral  10 . 
         [0044]    As embodied herein, and depicted in  FIG. 1 , a circuit diagram of a thin electrical wiring device  10  in accordance with a first embodiment of the present invention is disclosed. Before providing a detailed description of each component, it is noted that device  10  is comprised generally of a conductive path (between the line and the load), a fault response function, and a test capability. 
         [0045]    With regard to the conductive path between the line terminals  112  and the load terminals  114 , device  10  is properly connected to an AC power source by way of line terminals  112 . A phase conductive path  218  and a neutral conductive path  218 ′ extend from the line terminals  112  to interrupting contact assembly  110 . Movistor  124  is also coupled between the phase conductor  218  and the neutral conductor  218 ′. Sensor assembly  100 , as indicated by the dashed lines, may be coupled to the phase conductor  218 , the neutral conductor  218 ′, or both, depending on the sensor functionality. These elements will be discussed in detail below. When the contacts  110  are closed, AC power propagates along the phase conductor  218  to a load connected to the load terminals  114 . The return current from the load(s) propagates along neutral conductive path  218 ′. Load terminals  114  include feed through terminals  114   a  and/or plug receptacle terminals  114   b.  Thus when a true fault condition is sensed and detected, the circuit interrupter trips to terminate the current flowing through the fault. The state of the interrupting contacts  110 , i.e. open or closed, depends on the fault response circuitry. Reset button  116  is coupled to trip mechanism  108 . Reset button  116  enables circuit interrupter  110  to be closed (reset) after the fault condition has been removed, whereupon load terminals  114  and line terminals  112  are re-connected. 
         [0046]    In order to safe-guard the protection device  10  from voltage transients that occur on the electrical power distribution system, a metal oxide varistor may be included, such as MOV  124  across line terminals  112 , MOV  126  across load terminals  114   a,  or MOV  128  across load terminals  114   b.  Alternatively, surge protective devices can be included to safe-guard the protection device from voltage transients. 
         [0047]    Sensor assembly  100  is configured to sense at least one fault condition in the electrical distribution system. In other words, device  10  may include a GFCI, GFEP, AFCI, and/or a TVSS. Accordingly, sensor assembly  100  may include one or more sensors, depending on the functionality of device  10 . Sensor  100  is coupled to detector  102 . The output of the fault detector  102  is connected to a switch (SCR)  104 . SCR  104  is configured to energize solenoid  106  when signaled by detector  102 . When solenoid  106  is energized, trip mechanism  108  opens the interrupting contacts  110 . Interrupting contacts  110  may be closed by actuating reset button  116 . 
         [0048]    In addition, device  10  includes test circuit  120 . Test circuit  120  is coupled to the hot line conductor  218 , neutral load conductor  218 ′, or both. Test circuit  120  includes test switch  118 , which is actuated by a user to start the test cycle. Now that a high level description of device  10  has been provided, an explanation of some of the circuit components is provided in greater detail. 
         [0049]    If device  10  includes GFCI protection, sensor assembly  100  includes a sensor that is configured to sense the net differential current flowing in the hot conductive path and the neutral conductive path of the electrical distribution system. Under normal operating conditions, the net current in the load conductors is zero when device  10  provides power to a load. The current to the load and from the load are equal and opposite. 
         [0050]    As the name suggests, a ground fault occurs when a phase conductor becomes grounded. Some of the current flows to ground instead of returning back through sensor assembly  100 . Obviously, when current is siphoned off in this manner, the net current flowing through sensor  100  is not zero. Sensor assembly  100  senses the magnitude of the differential ground fault current. 
         [0051]    Those of ordinary skill in the art will understand that the GFCI sensor disposed in assembly  100  typically includes a toroidally shaped differential transformer. A GFCI sensor assembly may also be configured to detect grounded neutral conditions. Thus, a GFCI equipped in this manner will typically include a neutral (grounded neutral) transformer. When a grounded neutral condition is present, the neutral transformer provides the differential transformer with a differential signal to signal the occurrence of a grounded neutral condition. 
         [0052]    If device  10  includes AFCI protection, sensor assembly  100  includes a different type of sensor that is configured to sense high frequency disturbances superimposed on the power line frequency. These high frequency disturbances are indicative of an arcing condition. These disturbances may occur in the load current, the line voltage or both. In one approach, sensor assembly  100  may include a toroidally shaped current transformer for sensing load current, and/or a voltage divider for sensing line voltage. 
         [0053]    As noted above, sensor assembly  100  provides detector  102  with a sensor fault signal. Detector  102  determines if the characteristics of the fault signal are indicative of a true fault condition. Detector  102  is connected to silicon controlled rectifier (SCR)  104 . When a true fault condition is detected, detector  102  turns SCR  104  ON. In turn, SCR  104  activates trip solenoid  106  which releases trip mechanism  108 . When trip mechanism  108  is released, circuit interrupter contacts  110  are opened. As noted previously, circuit interrupter  110  is disposed between the line terminals  112  and the load terminals  114  of device  10 . While device  10  may be configured to respond to the various types of fault conditions by interrupting power, device  10  may also provide an indicator element that indicates the presence of a fault condition. The indicator can be a visual indicator or an audible indicator. The output from the indicator may be steady or intermittent. 
         [0054]    Referring back to test circuit  120  in  FIG. 1 , device  10  includes a test switch  118 . Test switch  118  may be operated by the user by depressing a test button  119 . In another embodiment test switch  118  may be coupled to reset button  116 . In this case, the test switch  118  is actuated by depressing the reset button  116 . Referring back to the embodiment shown in  FIG. 1 , when test switch  118  is closed, test circuit  120  is configured to simulate a true fault condition across line terminals  112 . Test circuit  120 , as shown in  FIG. 1 , is stylized to show both a GFCI test circuit and an AFCI test circuit. For example, the GFCI test circuit  120  may include resistor  122 . The current through resistor  122  produces a simulated ground fault condition. Alternatively, a test provision may be included that manually or automatically assesses whether the protection device has reached end-of-life. The test provision may be configured to deny reset, to indicate, or to indicate in advance of denying reset, when an end-of-life condition has been detected. 
         [0055]    The AFCI test circuit  120  may alternatively include a resistance  121  in series with a solid state switch  123 . Switch  123  is configured to open and close to produce an intermittent current through the resistance to thereby simulate an arc fault condition. 
         [0056]    As embodied herein and depicted in  FIG. 2 , a cross-sectional view of a thin electrical device  10  in accordance with the present invention is disclosed. A maximum depth (a) of about 1.0 inch behind the strap  206  may be achieved using one or more of the techniques described herein. In  FIG. 2 , a maximum depth above the strap (c) is approximately 0.300 inches, with a strap thickness (b) of about 0.05 inches. In achieving this, the various components and features of device  10  are typically as follows. The depth (h) of ground opening  210  is typically about 0.86 inches. The wall thickness (g) of compartment  216  is typically about 0.035 inches. The depth of compartment  216  is depth (h) plus the wall thickness (g), e.g., 0.895 inches. The back cover wall thickness (d) is approximately 0.065 inches. The printed circuit board is disposed inside back cover  204  to lie on a plane substantially parallel to surface  205 . The printed circuit board is spaced a dimension (e) from the back cover by 0.100 inches to accommodate components disposed on the printed circuit board. The printed circuit board has a thickness (j) of about 0.031 inches. Accordingly, the maximum height (f) of a component disposed between the ground blade compartment and the printed circuit board becomes 0.26 inches. Components, including electro-mechanical components, whose height is greater than about 0.26 inches (thick components) are disposed elsewhere within the housing of device  10 . In another embodiment, printed circuit board  238  includes an aperture disposed therein to accommodate the ground blade. As such, the depth behind the strap dimension may further be reduced. To those skilled in the art, such dimensions can be adjusted in mix and match combinations as long as the preferred depth dimensions are not violated. 
         [0057]    Referring to  FIG. 3 , a longitudinal cross-sectional view of the thin protective device  10  shown in  FIG. 1  is depicted. Device  10  includes a cover assembly  200  in which one or more plug receptacles  202  are disposed. A back cover  204  having a rear surface  205  mates with front cover  200 . Strap  206  provides a means for attaching device  10  to an outlet box (not shown). A grounding terminal  212  is disposed under strap  206 . The distance from the back of strap  206  and surface  205  is approximately (1) one-inch or less. It is in this sense that device  10  employs thin construction. Device  10  of the present invention facilitates outlet box installation because the thin construction alleviates the issues described in the Background Section of the Invention. In another embodiment, strap  206  may be configured to conform to the shape of the front cover  200  to facilitate placement of interior components. 
         [0058]    Each plug receptacle  202  includes at least two load terminal openings  208  to permit electrical interconnection between plug blades and corresponding load terminals  114   b.  A ground terminal opening  210  may also be provided to accommodate a plug having a ground blade. Opening  210  includes a ground contact  214  disposed therein. As alluded to above, when the plug is inserted into the openings, electrical continuity is established between receptacle load terminals  114   b  and the plug blades, and between the ground blade and ground contact  214 . The plug blades, of course, are connected to a power cord attached to an electrical appliance. Ground contact  214  is connected to grounding terminal  212  by an internal conductive path (not shown). 
         [0059]    With regard to thin construction, one limit to depth reduction relates to the length of the ground blade. For 120V/240V electrical distribution systems, for example, opening  210  must extend into device  10  approximately 0.860 inches to accommodate the ground plug blade. Opening  210  may lead to a region of free space within device  10 , or to an insulated compartment  216 . Compartment  216  is configured to electrically isolate the ground blade from other conductive surfaces included in device  10 . In one embodiment, the present invention is implemented by not disposing any components in the space between the bottom of compartment  216  and the interior surface of the back cover  204 . In another embodiment, smaller components may be disposed in this space, but cannot have a thickness greater than 0.260 inches if the overall depth behind the strap is approximately one (1) inch or less. 
         [0060]    In most wiring devices, the toroidal transformer is a relatively thick component. In the present invention, the thickness of toroidal transformers  100  must be addressed to thereby minimize the overall depth of the device behind the strap. Toroidal transformer  100  is disposed proximate to conductors  218 ,  218 ′. Conductors  218 ,  218 ′ couple line terminals  112  to the load terminals  114 . Conductors  218 ,  218 ′ must be sized to conduct the expected load current without overheating. The load current may typically be about 20 Amperes. 
         [0061]    In particular, fault sensing functionality is implemented by passing one or more of the line conductors  218 ,  218 ′ through the aperture of transformer(s)  100 . Line conductors  218 ,  218 ′ propagate the differential current signals sensed by the transformer(s)  100 . Transformers  100  include magnetic core(s)  220  and corresponding multiple turn winding(s)  222  surrounding the core. Current signals induce flux in the magnetic core that, in turn, produces a signal in the winding. Winding(s)  222  are coupled to detector  102  (See  FIG. 1 ). The material and shape of core(s)  220  are configured such that the signal in winding(s)  222  is detectable by detector  102 . Furthermore, winding(s)  222  need to be electrically isolated from conductors  218 ,  218 ′. The two conductors and the winding(s) are separated by air spaces and/or insulating barriers. Consequently, a toroidal transformer is typically a relatively thick component. A differential transformer, for example, and conductor include these typical dimensions: 
         [0000]    
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 Conductor diameter 
                  0.04 inches 
               
               
                   
                 Transformer inside diameter 
                 0.240 inches 
               
               
                   
                 Transformer outside diameter 
                 0.590 inches 
               
               
                   
                 Transformer thickness 
                 0.170 inches 
               
               
                   
                   
               
             
          
         
       
     
         [0062]    In an alternate embodiment, back cover  204  includes a protrusion  240  for accommodating a portion of sensor assembly  100 . Thus, in one embodiment, back cover  204  includes a major surface area  205  that is substantially parallel with the front face of cover  200 . However, back cover  204  also includes a protrusion  240  that extends from surface  205 . In one embodiment, protrusion  240  has a surface area that is approximately 0.400 square inches or less. The height of protrusion  240  is approximately 0.150 inches or less. Stated generally, a protrusion is an extension from surface  205  that permits the inclusion of various alternate components within the device. For example, protrusion  240  may be configured to accommodate large sized movistors. 
         [0063]    Because the MOV is another example of a relatively thick component, another depth reduction strategy relates to reducing the thickness of the MOV. A MOV that is located across-the-line, such as MOV  124 ,  126 , or  128 , is typically greater than 0.650 inches in diameter and 0.250 inches in thickness. The size of the MOV is proportional to its energy absorption capabilities. Thus, larger MOVs tend to do a better job of limiting the amplitude of voltage transients. In particular, MOVs are typically selected to limit the amplitude of the voltage transient to less than about three times the amplitude of the power source voltage to ensure that the protection device survives momentary voltage transients of this amplitude. Accordingly, one size reduction strategy relates to reducing the size of the MOVs while retaining the transient protection capabilities. 
         [0064]    Therefore, in one embodiment, the across-the-line MOVs are omitted. MOV  130  ( FIG. 1, 2 ) is disposed in series with an impedance device configured to absorb a major portion of energy during a surge event. However, the circuitry that is most vulnerable to voltage transients is protected by MOV  130 . The protected circuitry includes power supply  134  and detector  102 . The impedance device may be solenoid  106  ( FIG. 1 ). The impedance of solenoid  106  is frequency dependent, and is typically greater than 50 Ohms in response to high frequency signals such as voltage transients. Most of the energy from the voltage transient is substantially absorbed by solenoid  106  because the impedance of the solenoid is at least an order of magnitude greater than the impedance of MOV  130  at the voltage transient frequencies. MOV  130  absorbs the remainder of the transient energy. An appropriately sized MOV  130  may be less than or equal to 0.354 inches in diameter and 0.250 inches in thickness. 
         [0065]    In an alternative embodiment, MOV  130  may be replaced by capacitor  132  or by a similar transient voltage absorbing element. In yet another alternative embodiment, spark gaps may be included as a means for reducing MOV size or for replacing MOVs altogether. Spark gaps may be employed in combination with capacitors or other size-efficient components. 
         [0066]    Solenoid  106  is another relatively “thick” component. Of course, solenoid  106  is configured to activate trip mechanism  108  ( FIG. 1 ). Trip mechanism  108  includes an armature  224  that moves in response to a magnetic field produced by current flowing through solenoid  106  when SCR  104  turns ON. Trip mechanism  108  is configured to release (open) circuit interrupter  110  when armature  224  moves. Solenoid  106  includes multiple turns of wire  226  wound on a tubular portion of frame assembly  228  to form a bobbin. Armature  224  is slidably disposed within the tubular portion of frame assembly  228 . Frame assembly  228  may include a magnetic bracket  230  configured to increase the magnetic force applied to armature  224 . Typical dimensions associated with solenoid  106  are as follows: 
         [0000]    
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 Armature outside diameter 
                 0.125 inches 
               
               
                   
                 Bobbin outside diameter 
                 0.600 inches 
               
               
                   
                 Bobbin length 
                 0.240 inches 
               
               
                   
                 Bracket assembly height 
                 0.660 inches 
               
               
                   
                 Bracket assembly width 
                 0.350 inches 
               
               
                   
                   
               
             
          
         
       
     
         [0067]    Electronic components may be included in the list of relatively thick components. SCR  104 , for example, is typically housed in what is known as a TO-92 package whose height (including lead length provision) is typically 0.261 inches. 
         [0068]    Thus, thick components include one or more of a sensor  100 , SCR  104 , solenoid  106 , and/or MOV  124 . Components that are not thick components, such as conductor  218 , may be located between the bottom of opening  210  and the interior surface of back cover  204 . 
         [0069]    The present invention may also employ surface mount (SM) circuitry because SM circuits are relatively compact and are spatially efficient. Further, multiple circuits may be combined in a single integrated by way of hybrid device technology, ASIC technology, or monolithic integrated circuit technology. For example, miswire protection circuitry and end-of-life circuits may be disposed in such devices. Miswire protection protects the user from a miswired condition wherein AC power is connected to the feed-through terminals. End-of-life protection protects the user from a malfunction in the protective device that prevents the interruption or indication of a fault condition in the electrical distribution system. End-of-life protection circuits may include manual methods that alert the user to the end-of-life condition when the user depresses a button. Automatic end-of-life circuitry may activate an end-of-life indicator; decouple the load circuit from the line terminals, or both. If indication and power denial are both provided, the indication may precede power denial by a predetermined period. An indicator can be a flashing red indicator. The indicator, whether visual or audible, may be disposed on cover  200 . Reference is made to U.S. patent application Ser. No. 10/729,396 and U.S. patent application Ser. No. 10/668,654, which are incorporated herein by reference as though fully set forth in its entirety, for a more detailed explanation of automatic end-of-life power denial and/or indication. 
         [0070]    A portion of the circuitry and other components of device  10  may be disposed on a printed circuit board  238 . Printed circuit board  238  is usually less than or equal to about 0.031 inches in thickness. Alternatively, the components may be disposed on a printed circuit membrane. On the other hand, the printed circuit board may be apertured to permit the ground blade openings  210  and compartment  216 , if provided, to pass there-through. Alternatively, electronic or electro-mechanical components may be disposed on both sides of the printed circuit board to thereby conserve space. As such, electronic or electro-mechanical components that are coupled to the line terminals, or those that operate at or near the power source voltage may be disposed on one side of the printed circuit board. Those that are coupled to the power supply and that operate at typically less than 30 Volts may be disposed on the opposite side of the printed circuit board. 
         [0071]    As embodied herein, and depicted in  FIG. 4 , a latitudinal cross sectional view of a thin electrical wiring device in accordance with another embodiment of the present invention is shown. This embodiment discloses an improved test switch. Test switch  118  includes a test blade  300  that is disposed above strap  206 . One important feature of this embodiment is that test blade  300  is disposed above strap  206  to thereby reduce the depth behind the strap. Although test blade  300  and strap  206  are separated by an air spacing, known devices have had to include supplemental insulation to assure that the strap and test blades are electrically isolated from each other. Examples of supplemental insulation include non-conductive tape disposed around the strap or a plastic insulator interposed between the two. The need for supplemental insulation can be eliminated by a number of strategies or strategies in combination. 
         [0072]    As noted above, one strategy is to make the distance between the strap  206  and surface  302  of cover  200  as large as possible, i.e. about 0.300 inches. A distance greater than this may interfere with the alignment of the wall plate and/or weather-proof cover required to complete the installation of device  10 .  FIG. 3  illustrates another feature of this embodiment. When test switch  118  is in the closed position, test blade  300  connects test circuit  120  to a load terminal  114 . When test switch  118  is in the open position, approximately equal air gaps  304  and  306  break the electrical connection. The total air gap of test switch  118  (air gaps  304  plus  306 ) must be such that test circuit  120  is properly insulated during a voltage transient event. Test blade  300  only has to travel about half the distance to open or close the preferred air gap distance when two air gaps are used. Thus, the depth above the strap can be reduced by approximately 0.045 inches. Test blade  300  may be secured to test button  119  using snap fits (not shown). 
         [0073]    The limited amount of space on printed circuit board  238  on which to dispose electrical or electro-mechanical components is used to best advantage if components disposed thereon are principally operated at a low voltage, e.g., less than 30 Volts. Such components may be spaced apart from one another by approximately 0.01 inches. Components operating at or near the line voltage may be required to be spaced apart by 0.04 inches. 
         [0074]    In most related art circuits, a full wave power supply is employed. Therefore, a physical spacing must be provided between the line and load terminals, and the power supply terminals. One embodiment of the present invention eliminates this requirement by employing a half-wave power supply. A half wave power supply such as illustrated in  FIG. 1 . Note that the circuit ground reference is connected to the line neutral. Accordingly, the aforementioned spacing that is required by the related art is avoided, thus conserving space. 
         [0075]    With regard to the test circuit, the test circuit components may be disposed off of circuit board  238 . Only the low voltage portion of test circuit  120  may be disposed on circuit board  238 , i.e., the portion extending from line neutral  218  to button  119 . The test button  119  and the components that extend to load hot are not disposed on circuit board  238 . 
         [0076]    In an alternative embodiment, ancillary features may be included in device  10 . The ancillary features are implemented using various components that may be disposed, or partially disposed, in the housing portion above the strap. 
         [0077]    Referring to  FIG. 5 , a nightlight  500  is disposed in the front cover  200 . The nightlight is configured to broadcast light into a darkened space. The nightlight may turn on automatically when the level of ambient light is less than a predetermined threshold. The components associated with the nightlight include a lamp assembly, ambient light sensor, and/or lens. The lens is configured to occupy a portion of front cover  200 . Reference is made to U.S. Application Ser. No. 60/550,275, filed on Mar. 5, 2004, which is incorporated herein by reference as though fully set forth in its entirety, for a more detailed explanation of a nightlight disposed in a cover. 
         [0078]    Referring to  FIG. 6 , at least one switch  250  may be disposed in the front cover  200 . The at least one switch may be coupled to either the line terminals or load terminals of device  10 , to thereby provide switchable power to a set of auxiliary terminals. An indicator  252  may also be disposed in cover  200 . Reference is made to U.S. Application Ser. No. 60/553,795 filed on Mar. 16, 2004, which is incorporated herein by reference as though fully set forth in its entirety, for a more detailed explanation of a switch disposed in cover  200 . 
         [0079]    Other features may be accommodated by the present invention as well. For example, a membrane may be disposed behind cover  200 . The membrane is configured to protect the device from stray contaminants. The membrane may be disposed between the strap  206  and surface  302 . The present invention may also include a shutter mechanism that is configured to block the insertion of a plug into the plug receptacle openings when device  10  has been miswired. The shutters may also block the insertion of a metal object other than a plug into the plug receptacle to thereby prevent an electric shock. Reference is made to U.S. patent application Ser. Nos. 10/729,685 and 10/900,778, which are incorporated herein by reference as though fully set forth in its entirety, for a more detailed explanation of a device including membranes and/or shutters. 
         [0080]    The ancillary features illustrated above may be implemented in device  10  as stand-alone features, or in combination. In certain circumstances, when a plurality of such features is employed, the depth of the front cover to the strap may be about 0.500 inches. Alternatively, the depth behind the strap may be increased to approximately 1.100 inches or less. 
         [0081]    As embodied herein, and depicted in  FIGS. 7-11 , various configurations of circuit interrupter  110  in accordance with the present invention are disclosed. Referring to  FIG. 4 , pairs of plug receptacle terminals  114   b  and feed through terminals  114   a  have been permanently connected together electrically via unitary load terminal assemblies  400 . Bus bars  402  are disposed between a line terminal  112  and a load terminal assembly  400 . To those having ordinary skill in the art, bus bars  402  may be replaced by cantilever beams. 
         [0082]    Referring to  FIG. 8-11 , plug receptacle terminals  114   b  and feed through terminals  114   a  may or may not be permanently joined together, depending on whether a two-pole trip mechanism or a four-pole trip mechanism is being implemented. These figures are examples of how device  10  may be configured to prevent electrical connection between one or more sets of receptacle terminals and feed through terminals when device  10  has been miswired. Power does not flow to a user attachable load connected to plug receptacles  114   b  when device  10  is miswired (i.e. source power has been connected to feed through terminals  114   b ). 
         [0083]    Referring to  FIG. 8 , circuit interrupter  110  includes at least one assembly comprising two cantilever beams  500  and  501 , and a fixed contact  502 . When circuit interrupter  110  is in the reset position, trip mechanism  108  urges cantilever contact  500  to make electrical contact with the sandwiched cantilever contacts  501 . In response, sandwiched cantilever contacts  501  are driven towards fixed contact  502 . As a result, line terminal  112 , feed through terminal  114   a  and plug receptacle terminal  114   b  are electrically continuous. When circuit interrupter  110  is in the tripped position, trip mechanism  108  releases the cantilever beams  500 ,  501  and fixed contact  502  to electrically separate. Thus line terminal  112 , feed through terminal  114   a  and plug receptacle terminal  114   b  are electrically disconnected from each other. This arrangement eliminates hazards due to device miswiring. 
         [0084]    Referring to  FIG. 9 , a circuit interrupter  110  similar to the embodiment depicted in  FIG. 7  is shown. A bus bar assembly  600  for each of the hot and neutral current paths is included. Each bus bar assembly  600  includes two contacts  602 ,  604  and a flexible cable  606  that flexes to allow the bus bar assembly to move from a closed (reset) position to an open (tripped) position. Contacts  602 ,  604  and flexible cable  606  are configured to connect to a line terminal  112 , feed through terminal  114   a  and plug receptacle terminal  114   b.  When circuit interrupter  110  is reset, the bus bar assembly  600  interconnects line terminal  112 , feed through terminal  114   a  and plug receptacle terminal  114   b.  When circuit interrupter  110  is tripped, the bus assembly  600  breaks electrical connectivity between line terminal  112 , feed through terminal  114   a  and plug receptacle terminal  114   b.  Therefore, any potentially hazardous conditions are not present at the receptacle in the event of a miswire condition. 
         [0085]    Referring to  FIG. 10 , a circuit interrupter  110  includes rocker assembly  700 . Rocker assembly  700  includes pivot members  702  that are inserted into slot  703  disposed in conductive member  704 . Pivots  702  rotate within slot  703  while making electrical connection with conductive member  704 . Conductive surface  704  is connected to plug receptacle terminal  114   b.  Pivot members  702  move rotationally in response to motion of the latch block  714 . Latch block  714  moves upward during a reset operation, and moves downward when the device is tripped. Contacts  706  and  708  are connected to pivot members  702 . Contacts  710 ,  712  are respectively coupled to a line terminal  112  and a feed through terminal  114   a.  Latch block  714  causes pivot members  702  to connect contacts  706 ,  708  electrically to contacts  710 ,  712 , when circuit interrupter  110  is in the reset condition. In other words, a line terminal  112 , feed through terminal  114   a  and plug receptacle terminal  114   b  are connected together by way of pivot members  702 . On the other hand, latch block  714  causes pivot members  702  to break the electrical connections when circuit interrupter  110  is in the tripped condition. 
         [0086]    Alternatively, the rocker assembly  700  may include a unitized pivot member instead of individual members  702  (not shown). Alternatively, at least one pivot member may be disposed to pivot against, while making electrical connection with, a conductive surface coupled to a line terminal  112  or feed through terminal  114   a  (not shown.) The pivot member(s) are configured to electrically connect line terminal  112 , feed through terminal  114   a  and plug receptacle terminal  114   b  together when the circuit interrupter  110  is in the reset position. The pivot member(s) are configured to break the electrical connections among the line terminal  112 , feed through terminal  114   a  and plug receptacle terminal when the circuit interrupter  110  is in the tripped position. 
         [0087]    Referring to  FIG. 11 , circuit interrupter  110  includes at least one cantilever assembly including two cantilevers  800 ,  802 , and two fixed contacts  804 ,  806 . Cantilevers  800  and  802  are connected to a line terminal  112 . Fixed contacts  804  and  806  are connected to a plug receptacle terminal  114   b  and feed through terminal  114   a,  respectively. Trip mechanism  108  includes a reset solenoid  815  that urges the cantilevers  800 ,  802  into electrical connectivity with fixed contacts  804 ,  806 . As in the previous embodiments, the protective circuit assembly includes trip solenoid  106  that is configured to separate cantilevers  800 ,  802  from the fixed contacts  804 ,  806 , respectively. 
         [0088]    As embodied herein and depicted in  FIGS. 12-15 , detail views of a reset lock-out mechanism for use in the various embodiments of the invention are disclosed. Directions of movement are depicted as arrows. Referring to  FIG. 12 , device  10  is in the tripped condition, i.e., latch  826  is not coupled to escapement  830 . In order to accomplish reset, a downward force is applied to reset button  822 . Shoulder  1400  on reset pin  824  bears downward on electrical test switch  118  to enable a test signal. The test signal simulates a fault condition in the electrical distribution system such as a ground fault condition or an arc fault condition. 
         [0089]    Referring to  FIG. 13 , the test signal is sensed and detected by detector  102 . The detector provides a signal that causes solenoid  106  to activate armature  224 . Armature  224  moves in the direction shown, permitting hole  828  in latch  826  to become aligned with shoulder  1400 . The downward force applied to reset button  822  causes shoulder  1400  to continue to move downward, since it is no longer restrained by shoulder  1400 . Since shoulder  1400  is disposed beneath latch  826 , it is no longer able to apply a downward force on latch  826  to close electrical switch  118 . Accordingly, switch  118  opens to thereby terminate the activation of solenoid  52 . Armature  224  moves in the direction shown in response to the biasing force of spring  834 . 
         [0090]    As depicted in  FIG. 14 , the trip mechanism is in a reset condition. In other words, any the downward force on reset button  822 , as described above, is no longer present. Accordingly, latch  826  is seated on latching escapement  830 . 
         [0091]    Referring to  FIG. 15 , a user accessible test button  50  is coupled to the trip mechanism. When test button  50  in  FIG. 15  is depressed, device  10  is tripped by a mechanical linkage. In particular, when force is applied to test button  50 , a mechanical linkage  1402  urges latch  826  in the direction shown. Latch  826  opposes the biasing force of spring  834 . In response, hole  828  in latch  826  becomes aligned with escapement  830 . The trip mechanism is tripped because latch  826  is no longer restrained by escapement  830 . 
         [0092]    As has been described, the device resets as a consequence of solenoid  106  activating armature  224 . However, if the protective device  10  has reached an end-of-life condition, armature  224  is not activated. Therefore, the mechanical barrier is not removed and the mechanical barrier (shoulder) prevents the trip mechanism from resetting. The physical barrier prevents the protective device from being resettable if there is an end-of-life condition. 
         [0093]    Referring to  FIG. 16 , a schematic diagram in accordance with an alternate embodiment is depicted. The embodiment of  FIG. 9  is similar to the embodiment shown in  FIG. 11 . However, while separate test and reset buttons can be employed, the schematic in  FIG. 16  illustrates how a single button  808  may combine the functions of test button  119  and reset button  116 . For the sake of discussion, it is assumed that the interrupting contacts are initially in the reset position and switch mechanism  810  is in position  814 . Accordingly, when single button  808  is depressed, test circuit  120  is configured to produce a test signal for a predetermined period of time. The test signal simulates a fault condition that is sensed by sensor  100  and detected by detector  102 . SCR  104  turns ON, causing solenoid  106  to activate. Trip mechanism  108  causes the circuit interrupter  110  to trip, whereby cantilevers  800  and  802  move to the open (tripped) position, and switch mechanism  810  moves to position  812 . If single button  808  is subsequently depressed in the tripped state, test circuit  120  produces another test signal. If device  10  is operative and switch mechanism  810  is in position  812 , reset solenoid  816  activates to move circuit interrupter  110  to the closed (reset) position. Thus, a single test button may be employed to provide electrical signals for tripping and resetting a circuit interrupter. The use of a single button is yet another strategy for efficiently using space within device  10 . 
         [0094]    Accordingly, the combination of the test and reset buttons into a single button is another miniaturization strategy employed by the present invention. When the button is depressed, the protective device is tested, the circuit interrupter is tripped, and the protective device is reset. Resetting the protective device may be contingent on the protective device being operative (able to sense, detect, and interrupt a fault condition). As shown in  FIG. 16 , a single button  232  may be disposed within cover  200 . When depressed, button  232  activates a mechanical linkage that is configured to apply force to the trip mechanism  108 . Trip mechanism  108  opens circuit interrupter  110 . When single button  232  is depressed further, test switch  118  is closed ( FIG. 1 ). If device  10  is operative, solenoid  106  is activated. A mechanical barrier may be configured to prevent reset unless solenoid  106  has in fact activated. 
         [0095]    All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
         [0096]    The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. The term “connected” is to be construed as partly or wholly contained within, attached to, or joined together, even if there is something intervening. 
         [0097]    The recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. 
         [0098]    All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate embodiments of the invention and does not impose a limitation on the scope of the invention unless otherwise claimed. 
         [0099]    No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. 
         [0100]    It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. There is no intention to limit the invention to the specific form or forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention, as defined in the appended claims. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.