Abstract:
Electrical distribution systems, equipment and wiring devices are required to have their wiring connections properly identified to ensure proper operation of connected loads as well as the safety of users, however, errors in installation do occur. Electrical wiring errors are commonly called miswire conditions. The current invention is an integrated system and method of miswire protection and annunciation of system conditions for Arc Fault Circuit Interrupters (AFCIs) and other wiring devices, electrical systems and equipment. Electrical code and regulatory standards require certain wiring devices to include miswire protection with their standard features. These wiring devices, among others include Arc Fault Circuit Interrupters (AFCIs) and Ground Fault Circuit Interrupters (GFCIs) which are required to incorporate protection from miswire conditions with other electrical faults they are designed to protect circuits from, such as and including arc, ground, overload, short circuit, and surge.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation-in-part of U.S. patent application Ser. No. 13/274,291, filed On Oct. 14, 2011. 
    
    
     FIELD OF THE INVENTION 
     The present invention involves the detection of miswire conditions in electrical circuits, equipment and wiring devices, the means to interrupt the power supply to the connected load when the condition exists and means of annunciating system conditions including the occurrence of electrical faults such as arc, ground, overload, short circuit, surge and miswire, among others. The system and method of the current invention may be integrated with the control and monitoring systems of electrical circuits, equipment and wiring devices such as and including AFCIs (Arc Fault Circuit Interrupter) and GFCIs (Ground Fault Circuit Interrupter) that have detection and interruption circuitry with an electrically or electromagnetically-operated TRIP mechanism. 
     BACKGROUND OF THE INVENTION 
     With the increasing number of homeowners and non-professional personnel doing electrical wiring, the occurrence of miswire has been on the rise despite efforts of code regulators and electrical manufacturers to provide clear and easy-to-read manuals and installation instructions with electrical equipment and wiring devices. Wiring devices such as and including AFCIs and GFCIs in addition to their standard features, are required to have miswire protection. The current invention is an integrated system and method of miswire protection and annunciation of system conditions for Arc Fault Circuit Interrupters (AFCIs) and other wiring devices, electrical systems and equipment. System conditions include voltage, current, wattage or energy consumption, power on or off, and electrical faults such as and including arc, overload, short circuit, ground and miswire, among others. Prior arts use visual indicators such as lights and/or audible alarms to signal the occurrence of electrical faults and without identification of which faults occur. The current invention involves additional features of annunciation which include pre-recorded, graphic and alpha-numeric display of system conditions and the faults that occur in electrical circuits, equipment or wiring devices such as and including AFCIs and GFCIs. The annunciation may be within the electrical system, equipment or wiring device or in a remote location through wired or wireless interfaces. 
     For purposes of this invention, the following terms are used and mean the same as or substitute for the other:
         a) AC—in electrical terms, this refers to alternating current   b) DC—in electrical terms, this refers to direct current   c) AFCI or AFCIs (in singular or plural form)—commonly known as Arc Fault Circuit Interrupter   d) GFCI or GFCIs (in singular or plural form)—commonly known as Ground Fault Circuit Interrupter   e) PSD or PSDs (in singular or plural form)—Protection System or Device such as an electrical system, equipment or device equipped with a monitoring and control circuit for fault detection and interruption such as and including GFCIs and AFCIs.   f) LINE WIRE—also known as HOT or LIVE wire   g) NEUTRAL WIRE—also known as COLD wire or without potential   h) MICROPROCESSOR—also called microcontroller or a small computer Integrated Circuit with processor, memory and programmable input and output peripherals.   i) TRIP or TRIPPED—term to indicate a contactor or switch position being OFF, a button designation for OFF position, turn OFF or turned OFF, switch OFF.   j) RESET—term to indicate a contactor or switch position being ON, a button designation for “ON” position, turn ON or turned ON.   k) OPTOCOUPLER—an electronic device for switching an isolated circuit   l) SCR or SCRs (in singular or plural form)—SILICON CONTROLLED RECTIFIERS or solid-state switchers reacting to the flow of current to switch a circuit ON or OFF   m) PROPERLY WIRED—in relation to a circuit, equipment or wiring device, means that the LINE-SIDE LINE wire is connected to the LINE-SIDE LINE terminal, the LINE-SIDE NEUTRAL wire is connected to the LINE-SIDE NEUTRAL terminal, the LOAD-SIDE LINE wire is connected to the LOAD-SIDE LINE terminal, and the LOAD-SIDE NEUTRAL wire is connected to the LOAD-SIDE NEUTRAL terminal. Additionally, for grounded circuits, this means that the GROUND wire is connected to the GROUND terminal.   n) LINE-SIDE—means that part of an electrical circuit, equipment or device which is intended for connection of the main power supply.   o) LOAD-SIDE—means that part of an electrical circuit, equipment or device which is intended for connection of the LOAD.   p) SOLENOID-ACTUATED—also mean electromagnetically-actuated, pertains to the method of actuating the RESET or TRIP mechanism of PSDs. When the term electromagnetic is used in conjunction with a TRIP or RESET mechanism or action, it would mean solenoid-actuated.   q) SOLENOID—refers to an assembly consisting of wires wound on a core to produce a uniform magnetic field, a plunger which is actuated by the magnetic field which attaches to a fixture for latching or unlocking RESET or TRIP mechanisms such as those of a contactor.   r) LED—refers to Light Emitting Diodes which are available in different colors and are used for visual annunciation.   s) LCD—refers to Liquid Crystal Display for alphabetic, numeric or alpha-numeric annunciation.   t) NO—for auxiliary contacts mean Normally Open   u) NC—for auxiliary contacts mean Normally Close.   v) PRESS or PRESSED—refers to switching of contacts by pressing a button   w) CODE—as used with and in reference to a microprocessor means the program that drives its input and output peripherals and all other processing functions. Code-driven means the same as software-driven.       

     The most common miswire conditions relative to PSDs include the following:
         LINE-SIDE and LOAD-SIDE reversed wiring—this is when the LINE-SIDE wires are connected to the LOAD-SIDE terminals and the LOAD-SIDE wires connected to the LINE-SIDE terminals of the PSD;   LINE-SIDE LINE and NEUTRAL reversed wiring—this is when the LINE-SIDE LINE wire is connected to the LINE-SIDE NEUTRAL terminal and the LINE-SIDE NEUTRAL Wire is connected to the LINE-SIDE LINE Terminal of the PSD; and   LINE-SIDE and LOAD-SIDE crossed wiring—this is when the LINE-SIDE LINE wire is connected to the LOAD-SIDE NEUTRAL terminal, the LINE-SIDE NEUTRAL wire is connected to the LOAD-SIDE LINE terminal, the LOAD-SIDE LINE wire is connected to the LINE-SIDE NEUTRAL terminal and the LOAD-SIDE NEUTRAL wire is connected to the LINE-SIDE LINE terminal of a PSD. While this may be considered a miswire condition by itself, it is actually the combination of the two miswire conditions mentioned above.       

     The current invention is for PSDs with a detection and interruption system which generally employs a contactor or similar devices with switching and tripping mechanisms. The most common contactors used for PSDs have a solenoid-actuated TRIP mechanism, and a RESET mechanism which could either be manually-actuated or solenoid-actuated. The present invention is applicable to all types and variations of contactors provided with a tripping mechanism. 
     Although miswire is typically detected the first time a PSD is powered on after installation, miswire detection is integrated into a PSD&#39;s code routine and therefore continuously monitored even after the PSD&#39;s first use. With a miswire condition present, the PSD will trip whenever the device is RESET, and with certain types of contactors and miswire conditions, the PSD would not turn ON at all, maintaining an OFF position until the wiring is done properly. 
     To highlight the significance of the present invention, differences with prior arts are cited below for reference: 
     U.S. Pat. No. 7,751,162B1 (July 2010 Packard et al) disclosed a protective device with miswire protection which is specifically for a Ground Fault Circuit Interrupter device. The miswire circuit included a resistor which is intended to generate a differential current over a pre-determined value. This is different from the present invention which uses a code-driven microprocessor-controlled integrated system and method of detection and interruption. 
     U.S. Pat. No. 7,633,726B2 (December 2009 Huang et al) disclosed a protective device with miswire protection which is practically a Ground Fault Circuit Interrupter. This patent does not have a circuit to detect miswire conditions on either LINE or LOAD side and only relies on the operation of electromagnetic solenoids for TRIP and RESET of the contactor. When the LINE-SIDE and LOAD-SIDE wires are reversed and the device is on TRIP condition, the device is rendered non-operational since the operation of the TRIP and RESET SOLENOIDS depend only on power being on and device properly wired, which is different from the present invention which uses a code-driven MICROPROCESSOR-controlled integrated system and method of detection and interruption which functions whether the power supply is connected to the LOAD or LINE side of the PSD. 
     U.S. Pat. No. 7,538,994B2 (May 2009 Bonilla et al) disclosed a protective device with miswire protection which is practically only a Ground Fault Circuit Interrupter device. The disclosure relies on having the GFCI in a TRIPPED or OFF position before first powered on wherein a locking plate is pressed to engage a projection on the back side of the plunger to connect to a secondary contact to close a circuit. The RESET BUTTON when pressed can not engage with the latching plate. Only when the LINE side is powered on that the plunger releases the locking plate and allow RESET to occur. This is different from the present invention which uses a code-driven microprocessor-controlled integrated system and method of detection and interruption. The present invention also do not require that the PSD be initially on OFF position at first installation. 
     U.S. Pat. No. 7,403,086 B2 (July 2008 Wu et al) like the U.S. Pat. No. 7,633,726B2 (December 2009 Huang et al) Wu et al disclosed a protective device with miswire protection which is practically a Ground Fault Circuit Interrupter and for that particular device and circuitry only which will not apply to any other wiring devices as AFCI or others that are operating in different principles. This patent does not have a circuit to detect miswire conditions on either LINE or LOAD side of the device and only relies on the operation of electromagnetic solenoids for TRIP and RESET of the contactor. When the LINE side wires are miswired to the LOAD side, the device is rendered non-operational since the operation of the TRIP and RESET SOLENOIDs depend only on power being on. This is different from the present invention which uses a code-driven MICROPROCESSOR-controlled integrated system and method of detection and interruption which functions whether the power supply is connected to the LOAD or LINE side of the PSD. 
     U.S. Pat. No. 6,226,161 B1 (May 2001 Neiger et al)—like all miswire protection patents mentioned above, this patent disclosed a GFCI incorporating a miswire protection which is designed to work only with a GFCI receptacle outlet. In the disclosures of this patent, four bridge circuits are utilized to derive DC power supply to indicate a miswire condition and that the alarm remain on and can not be shut-OFF until corrected. Unlike the present invention the miswire protection detects a miswire condition and feeds it back to the MICROPROCESSOR which through a code-driven routine signals the TRIP circuit to activate the TRIP mechanism and the corresponding signal to activate the annunciation of audible and visual alarms or indicators. 
     SUMMARY OF THE INVENTION 
     The current invention is an integrated system and method of miswire protection and annunciation of system conditions for Arc Fault Circuit Interrupters (AFCIs) and other wiring devices, electrical systems and equipment. System conditions include voltage, current, wattage or energy consumption, power on or off, and electrical faults such as and including arc, overload, short circuit, ground and miswire, among others. For purposes of this patent application, a miswire condition could mean any of the following conditions:
         LINE-SIDE and LOAD-SIDE reverse wiring—this is when the LINE-SIDE wires are connected to the LOAD-SIDE terminals and the LOAD-SIDE wires connected to the LINE-SIDE terminals of a PSD; or   LINE-SIDE LINE and NEUTRAL Reversed wiring—this is when the LINE-SIDE LINE wire is connected to the LINE-SIDE NEUTRAL terminal and the LINE-SIDE NEUTRAL Wire is connected to the LINE-SIDE LINE Terminal of a PSD; or   LINE-SIDE and LOAD-SIDE crossed wiring—this is when the LINE-SIDE LINE wire is connected to the LOAD-SIDE NEUTRAL terminal, the LINE-SIDE NEUTRAL wire is connected to the LOAD-SIDE LINE terminal, the LOAD-SIDE LINE wire is connected to the LINE-SIDE NEUTRAL terminal and the LOAD-SIDE NEUTRAL wire is connected to the LINE-SIDE LINE terminal of a PSD. While this may be considered a miswire condition by itself, it is actually the combination of the above-mentioned miswire conditions.       

     The present invention is intended to detect a miswire condition as part of the PSD code routine which is important especially the first time it is powered ON to allow the installer to make corrections. The invention involves a combination of electrical, electronic, mechanical, electromagnetic and electro-mechanical components which are incorporated into the PSD that implements the detection, interruption and annunciation of system conditions. When the system detects a miswire condition, the MICROPROCESSOR, through a code-driven routine signals the TRIP circuit to activate the TRIP mechanism and the annunciation of audible and visual alarms or indicators. When a miswire condition is detected, power to the connected load is shut OFF through a TRIP mechanism which trips every time the PSD is powered ON until the condition is corrected. 
     The monitoring and control system of a PSD consists of its detection, switching, interruption and annunciation systems and their components. With a receiver and transmitter interface, the PSD may be operated and monitored through wireless medium from a remote location or control panel. Alternatively, the PSD may be wired with suitable interface to be operated and monitored from a remote location or control panel. 
     The current invention is for PSDs with a detection and interruption system which generally employs a contactor or similar devices with switching and tripping mechanisms. The most common contactors used for PSDs have a solenoid-actuated TRIP mechanism, and a RESET mechanism which could either be manually-actuated or solenoid-actuated. The present invention is applicable to all types and variations of contactors provided with a tripping mechanism. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG.  1 —is derived from a block diagram of an AFCI disclosed in Tomimbang et. al patent application Ser. No. 13/274.291, filed in Oct. 14, 2011. For exemplary purposes and to represent a PSD, an AFCI is used with the current invention. An AFCI provides circuit protection from various electrical faults such as and including arc, surge, short circuit, overcurrent and miswire. It could come in various types such as and including cord, circuit breaker, and receptacle outlet type. The receptacle outlet type AFCI is used as example for purposes of this invention as it is typical of a device with a TRIP and RESET mechanism with LINE-SIDE and LOAD-SIDE utilizing LINE, NEUTRAL and GROUND connections. 
       The monitoring and control system of a PSD consists of its detection, switching, interruption, and annunciation systems and components. With a receiver and transmitter interface, the PSD may be operated and monitored through wireless medium from a remote location or control panel. Alternatively, the PSD may be wired with suitable interface to be operated and monitored from a remote location or control panel. 
       The main components of an AFCI, among others include the LINE-SIDE TERMINALS  1 / 2 / 3 , LOAD-SIDE TERMINALS  4 / 5 / 6 , HECS  7 , BUFFER AMPLIFIER AND PHASE SHIFT CORRECTION CIRCUIT  8 , TRIP AND RESET SENSING CIRCUIT  14 , TRIP and RESET SWITCHING CIRCUIT  13 , AUDIBLE AND VISUAL INDICATORS  17 / 18 , ELECTROMAGNETIC TRIP AND RESET MECHANISM OR CONTACTOR  12 , MICROPROCESSOR  11 , and DC POWER SUPPLY or SMPS  9 . 
       The illustration in  FIG. 1  of a single-pole CONTACTOR  12  is a representation of a switching device or contactor which could be a single-pole (LINE only), two-pole (LINE and NEUTRAL), or any number of contacts and combinations as applicable for single or multi-phase systems which the current invention may be applied. 
       A VOLTAGE DIVIDER CIRCUIT  22  is connected across LINE  1  and NEUTRAL  2  on the LINE-SIDE of the PSD. 
       FIG.  1 A—is a legend to the components and parts as illustrated in  FIG. 1 . 
       FIG.  2 —illustrates a portion of an AFCI circuit disclosed in Tomimbang et. al patent application Ser. No. 13/274,291 filed in Oct. 14, 2011. While the electromagnetic CONTACTOR  12  is diagrammatically shown as a single-pole switching device as illustrated in  FIG. 1 , it is a representation of a switching device or contactor which could be a single-pole (LINE only), two-pole (LINE and NEUTRAL), or any number of contacts and combinations as applicable for single or multi-phase systems which the current invention may be applied. 
       This illustration is for a system which uses a double-solenoid CONTACTOR  12  where separate SOLENOIDS  24 / 25  independently operate the TRIP and RESET functions of the PSD. 
       The CONTACTOR  12  is equipped with TRIP and RESET BUTTONS  70 / 71 , CONTACT POINTS  26 , RESET SOLENOID  24 , TRIP SOLENOID  25 , and optionally, auxiliary contacts which were not shown on the illustration. 
       The TRIP AND RESET INDICATOR CIRCUIT  14  is composed of an OPTOCOUPLER  38  and associated electronic components  36 / 37 / 38 / 39 / 40  which feeds back signal to the MICROPROCESSOR  11  to indicate the CONTACTOR CONTACTS  26  position whether on TRIP or RESET. The components cited are basic and illustrative where an actual circuitry may include other components to satisfy specific design requirements but with the same principles and intents of the current invention. 
       The TRIP and RESET SWITCHING CIRCUIT  13  is composed of switching devices such as and including SILICON CONTROLLED RECTIFIERS (SCR)  27 / 28  or thyristors, or other switching devices, OPTOCOUPLERS  31 / 32  and associated electronic components intended to trigger the RESET or TRIP SOLENOIDS  24 / 25  through code-driven commands from the MICROPROCESSOR  11  as called for by pressing the RESET or TRIP BUTTONS  70 / 71 , or when an electrical fault occurs. The components cited are basic and illustrative where an actual circuitry may involve other components to satisfy specific design requirements but with the same principles and intents of the current invention. With a receiver and transmitter interface, the PSD may be operated and monitored through wireless medium from a remote location or control panel. Alternatively, the PSD may be wired with suitable interface to be operated and monitored from a remote location or control panel. 
       FIG.  2 A—is a legend to the components and parts as illustrated in  FIG. 2 . 
       FIG.  3 —is a simplified representation of  FIG. 2  with a double-solenoid 2-pole CONTACTOR  12  where separate SOLENOIDS  25 / 24  independently operate the PSD TRIP and RESET functions. The miswire detection and interruption system components are shown. This 2-pole CONTACTOR  12  is typically used on wiring devices such as and including GFCI and AFCI receptacle outlets. 
       The LINE-NEUTRAL INDICATOR CIRCUIT  56  feeds back signal to the MICROPROCESSOR  11  to determine when the LINE  1  and NEUTRAL  2  wiring connections are reversed. 
       The TRIP/RESET INDICATOR CIRCUIT  14  feeds back signal to the MICROPROCESSOR  11  to indicate CONTACTOR CONTACTS  45  position. 
       PULL-UP RESISTORS  68 / 68 A are intended to ensure the input to the MICROPROCESSOR  11  Logic control system for indication of TRIP and RESET conditions are at the expected logic levels. When the TRIP or RESET BUTTONS  71 / 70  are open, the voltage of the MICROPROCESSOR  11  gate input is pulled up to the level of the input voltage or the DC POWER SUPPLY voltage which is considered logic “HIGH”. When the TRIP or RESET BUTTONS are closed, the input voltage at the gate goes to ground or low level which is considered logic “LOW”. 
       With a receiver and transmitter interface, the PSD may be operated and monitored through wireless medium from a remote location or control panel. Alternatively, the PSD may be wired with suitable interface to be operated and monitored from a remote location or control panel. 
       FIG.  3 A—is a legend to the components and parts as illustrated in  FIG. 3 . 
       FIG.  3 B—is a continuation of the legend of  FIG. 3A  to the components and parts as illustrated in  FIG. 3 . 
       FIG.  4 —represents a PSD circuitry utilizing a 2-pole CONTACTOR  57  with a solenoid-actuated TRIP and a manual RESET operation. 
       The LINE-NEUTRAL INDICATOR CIRCUIT  56  feeds back signal to the MICROPROCESSOR  11  to determine when the LINE  1  and NEUTRAL  2  wiring connections are reversed. 
       The TRIP/RESET INDICATOR CIRCUIT  14  feeds back signal to the MICROPROCESSOR  11  to indicate CONTACTOR CONTACTS  59  position. 
       A PULL-UP RESISTOR  68  is connected through the auxiliary contact NO  60  and is intended to ensure the input to the MICROPROCESSOR  11  Logic control system for indication of TRIP and RESET conditions is at the expected logic levels. 
       When the manual RESET  58  is off and the auxiliary contact NO  60  is open, the voltage of the MICROPROCESSOR  11  gate input is pulled up to the level of the input voltage or the DC POWER SUPPLY voltage which is considered logic “HIGH”. When the manual reset is pressed and the auxiliary contact NO  60  is closed, the input voltage at the gate goes to ground or low level which is considered logic “LOW” which according to the MICROPROCESSOR logic control set-up is an indication that the manual RESET  58  switch was pressed. 
       When the TRIP BUTTON  71  is open, the voltage of the MICROPROCESSOR gate input is pulled up to the level of the input voltage or the DC POWER SUPPLY voltage which is considered logic “HIGH”. When the TRIP BUTTON  71  is closed, the input voltage at the gate goes to ground or low level which is considered logic “LOW”. 
       With a receiver and transmitter interface, the PSD may be operated and monitored through wireless medium from a remote location or control panel, with exception of the RESET  58  operation which is manual. Alternatively, the PSD may be wired with suitable interface to be operated and monitored from a remote location or control panel. 
       FIG.  4 A—is a legend to the components and parts as illustrated in  FIG. 4 . 
       FIG.  4 B—is a continuation of the legend of  FIG. 4A  to the components and parts as illustrated in  FIG. 4 . 
       FIG.  5 —represents a PSD circuitry with a 2-pole contactor  74  with a single-solenoid-actuated TRIP and RESET operation. 
       The LINE-NEUTRAL INDICATOR CIRCUIT  56  feeds back signal to the MICROPROCESSOR  11  to determine when the LINE  1  and NEUTRAL  2  wiring connections are reversed. The TRIP/RESET INDICATOR CIRCUIT  14  feeds back signal to the MICROPROCESSOR  11  to indicate CONTACTOR CONTACTS  75  position. 
       PULL-UP RESISTORS  68 / 68 A are intended to ensure the input to the MICROPROCESSOR  11  Logic control system for indication of TRIP and RESET conditions is at the expected logic levels. When the TRIP or RESET BUTTONS  71 / 70  are open, the voltage of the MICROPROCESSOR gate input is pulled up to the level of the input voltage or the DC POWER SUPPLY voltage which is considered logic “HIGH”. When the TRIP or RESET BUTTONS  71 / 70  are closed, the input voltage at the gate goes to ground or low level which is considered logic “LOW”. 
       With a receiver and transmitter interface, the PSD may be operated and monitored through wireless medium from a remote location or control panel. Alternatively, the PSD may be wired with suitable interface to be operated and monitored from a remote location or control panel. 
       FIG.  5 A—is a legend to the components and parts as illustrated in  FIG. 5 . 
       FIG.  5 B—is a continuation of the legend of  FIG. 5A  to the components and parts as illustrated in  FIG. 5 . 
         FIG. 6  Is a table consisting of Annunciation of System and Fault Conditions which shows the different ways and combinations of annunciation of system and fault conditions. The annunciation could be an audible alarm, a visual display or combination thereof, within the PSD itself or remotely. With a receiver and transmitter interface, the PSD may be operated and monitored through wireless medium from a remote location or control panel. Alternatively, the PSD may be wired with suitable interface to be operated and monitored from a remote location or control panel. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     References will now be made in detail to describe the exemplary embodiments of the present invention, which are in part illustrated in the accompanying drawings. Details disclosed herein are not to be interpreted as limiting, but rather as basis for the claims and teaching one skilled in the art how the present invention could be employed in any appropriately detailed system, structure or manner. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like components, or functions. System components cited are basic, illustrative and not to be interpreted as limiting, where an actual circuitry may involve other components to satisfy specific design requirements but with the same principles and intents of the current invention. 
     Miswire protection is an addition to the standard features of a PSD which for an AFCI, include protection from different electrical faults such as arcs, overload, short circuit, surge, among others. For a GFCI, miswire protection is added to its standard features including protection from electrical faults such as ground, overload, short circuit, surge, among others. 
     The monitoring and control system of a PSD consists of its detection, switching, interruption and annunciation systems and their associated components. With a receiver and transmitter interface, the PSD may be operated and monitored through wireless medium from a remote location or control panel. Alternatively, the PSD may be wired with suitable interface to be operated and monitored from a remote location or control panel. Exclusions apply for remote operation of manual RESET  58 . 
     The system of miswire protection in this invention consists of the LINE-SIDE and LOAD-SIDE terminal connections  1 / 2 / 3 / 4 / 5 / 6 , a SWITCHED MODE POWER SUPPLY (SNIPS) or alternative DC POWER SUPPLY  9 , a CONTACTOR  12 / 57 / 74 , TRIP and RESET SWITCHING CIRCUIT  13 , TRIP AND RESET INDICATOR CIRCUIT  14 , MICROPROCESSOR  11 , INTEGRATED CIRCUIT HALL EFFECT CURRENT SENSOR  7  and other electrical, electronic, electromagnetic, electro-mechanical components and interconnections. These same components are used by the PSD as part of other protection systems which among others include arc, ground, overload, short circuit and surge faults. 
     Whenever the term connected to, fed to, feeds back to, or any other functional terms in relation to MICROPROCESSOR  11  are used in this invention, they should be interpreted as electrical or electronic connections or signals to specific ports on the MICROPROCESSOR  11  designated for the particular functions the circuits are intended for. 
     The voltage divider  22  shown in  FIG. 1  is intended to maintain current flow to the BUFFER AMPLIFIER AND PHASE SHIFT CORRECTION CIRCUIT  19  of the PSD even when the LINE  1  and NEUTRAL  2  connections are miswired to ensure continuous availability of AC Line reference or synchronization for the MICROPROCESSOR  11 . This AC LINE synchronization is required by PSD monitoring and control systems for among others, proper sampling of signals, zero-crossing reference and timing of SCR firing. PSD fault detection code routines are based on analysis of HECS  7  outputs. Likewise, system conditions such as and including voltage, current, wattage are derived from the HECS  7  output signals. 
     Operation of the TRIP SOLENOID  25 / 62 / 78  is code-driven and triggered by pressing the TRIP BUTTON  71  or by the occurrence of any of the different electrical fault conditions the PSD is designed for, including miswire, 
     Operation of the RESET SOLENOID  24 / 78  is code-driven through a RESET BUTTON  70 . In case of manual-RESET PSDs, there is no RESET SOLENOID but instead a manually-operated RESET BUTTON  58  is used to mechanically latch the CONTACTOR CONTACTS  59 . 
     BRIDGE RECTIFIERS  33 / 34  are each connected on the LINE-SIDE and the LOAD-SIDE of the PSD. This is to ensure that DC power supply is always available to the PSD even when LINE-LOAD miswire occurs on the main AC power supply connection. With this set-up, power is always available to the DC power-driven components of the PSD even when a miswire condition exists, provided that the main AC power supply is on. The DC power-driven components include the MICROPROCESSOR  11 , the CURRENT SENSOR  7  and OPTOCOUPLERS  31 / 32 / 38 / 51 / 66 / 82 . Optional AUXILIARY CONTACTS  47 / 48 / 60 / 61 / 76 / 77  are shown as part of the CONTACTOR  12 / 57 / 74  for any additional switching, feedback or signaling functions. 
     The LINE-NEUTRAL INDICATOR CIRCUIT  56  with RESISTORS  52 / 53  and OPTOCOUPLER  51  is connected across NEUTRAL  2 / 54  and GROUND  3 . This circuit feeds back signal to the MICROPROCESSOR  11  to determine when the LINE  1  and NEUTRAL  2  wiring connections are reversed. Through the PSD&#39;s MICROPROCESSOR code routines for monitoring and detection of system conditions and faults, the contactor trips when a miswire occurs. 
     When the PSD is properly wired, the LINE-NEUTRAL INDICATOR CIRCUIT  56  is normally connected to NEUTRAL  2 / 54 . Since the NEUTRAL  2  potential with the GROUND  3  is practically zero or negligibly low and not enough to trigger the OPTOCOUPLER  51 , this FEEDBACK  73  considered logic “HIGH” to MICROPROCESSOR  11  which indicates proper wiring or that no miswire condition exists. This is according to MICROPROCESSOR  11  LOGIC CONTROL set-up. 
     If the LINE  1  and NEUTRAL  2  wiring connections are reversed, the LINE-NEUTRAL INDICATOR CIRCUIT  56  is connected to the LINE instead of NEUTRAL. In this case, there is a potential in the LINE-NEUTRAL indicator circuit across LINE  1 / 55  and GROUND  3  driving the OPTOCOUPLER  51  with a FEEDBACK  73  considered logic “LOW” to MICROPROCESSOR  11  which indicates improper wiring or the existence of a miswire condition. By the PSD MICROPROCESSOR  11  code routine the TRIP SOLENOID  25 / 62 / 78  is activated, tripping the CONTACTOR  12 / 57 / 74  and switching the ANNUNCIATION CIRCUIT  17 / 18  with corresponding audible and/or visual indications. The MICROPROCESSOR  11  logic control set-up for the FEEDBACK  73  from the LINE-NEUTRAL INDICATOR CIRCUIT  56  may alternatively be reversed where connection to the LINE  1 / 55  could indicate a normal condition and connection to NEUTRAL  2 / 54  as a miswire condition. 
     A TRIP/RESET INDICATOR CIRCUIT  14  is connected across LINE  4  and NEUTRAL  5  on the LOAD side of the PSD. The MICROPROCESSOR  11  logic control for the TRIP/RESET INDICATOR CIRCUIT  14  is set up where current flow to the circuit indicates a RESET position and absence of current flow indicates a TRIP condition. When the PSD is wired properly and the CONTACTOR  12 / 57 / 74  is in OFF position with the main power supply ON, the CONTACTS  45 / 59 / 75  are open and therefore there is no power to the LOAD side of the PSD. At this point there is no current flow to the TRIP/RESET INDICATOR CIRCUIT  14  and the FEEDBACK  44  to MICROPROCESSOR  11  considered logic “HIGH” which indicates that the contactor is on TRIP position. When the CONTACTOR  12 / 57 / 74  is RESET, current flows through the TRIP/RESET INDICATOR CIRCUIT  14  triggering the OPTOCOUPLER  38  with a FEEDBACK  44  to MICROPROCESSOR  11  considered logic “LOW” which indicates that the CONTACTOR  12  is on RESET. The MICROPROCESSOR  11  LOGIC CONTROL set-up for the TRIP/RESET INDICATOR CIRCUIT  14  feedback may alternatively be reversed by the PSD code routine to indicate the opposite conditions. The TRIP/RESET INDICATOR CIRCUIT  14  may alternatively be connected across LINE and GROUND instead of LINE and NEUTRAL for the same purpose and using the same principle above. As well, the TRIP/RESET INDICATOR CIRCUIT  14  may alternatively be connected across one of the AUXILIARY CONTACTS  47 / 48 / 60 / 61 / 76 / 77  and the DC POWER SUPPLY instead of LINE and NEUTRAL for the same purpose and using the same principle above. 
     PULL-UP RESISTORS  68 / 68 A are used for the MICROPROCESSOR  11  logic control for switching of TRIP and RESET circuits. They are intended to ensure the input to the MICROPROCESSOR  11  Logic control system is at the expected logic levels. 
     For a PSD with a CONTACTOR  57  which has a solenoid-actuated TRIP and manually-actuated RESET, a PULL-UP resistor is connected in series with the auxiliary contact NO  60  to GROUND. When the TRIP BUTTON  71  is open, the voltage of the MICROPROCESSOR  11  gate input is pulled up to the level of the input voltage or the DC POWER SUPPLY voltage which is considered logic “High”. When the TRIP BUTTON  71  is closed, the input voltage at the gate goes to ground which is considered logic “LOW”. Alternatively, through the MICROPROCESSOR  11  code routine, the Logic set-up may be reversed for indications opposite to the above. Likewise, a PULL-DOWN resistor circuit may be used in lieu of a PULL-UP resistor circuit, with corresponding change in the MICROPROCESSOR  11  logic set-up, applying the same principles disclosed in this invention. 
     For a PSD with solenoid-actuated TRIP and RESET, PULL-UP RESISTORS  68 / 68 A are used with the RESET BUTTON  70  and TRIP BUTTON  71 . The PULL-UP RESISTORS  68 / 68 A may also use the auxiliary contacts NO  47 / 76  or NC  48 / 77  in the same principle above. Likewise, a PULL-DOWN resistor circuit may be used in lieu of a PULL-UP resistor circuit, with corresponding change in the MICROPROCESSOR  11  logic set-up, applying the same principles disclosed in this invention. 
     As an additional or optional system for TRIP/RESET indication, the MICROPROCESSOR  11  Non Volatile Memory (NVM) may be used in conjunction with the TRIP/RESET INDICATOR CIRCUIT  14  or independently to identify the contactor position of the PSD on its last operation cycle. This could be incorporated in the PSD code routine as a means to confirm the contactor position. 
     In prior arts, the annunciation system used with PSDs is generally confined with LED display to indicate ON and OFF conditions, where the former is represented by a Green-colored LED and the latter by a red-colored LED. The red-colored LED is also an indication that the PSD tripped by pressing the TRIP BUTTON  71  or due to a fault as a general method of annunciation and without distinction or identification of which fault occurs. The current invention involves a code-driven system and method of annunciating system conditions and faults that occur in a PSD. The annunciation system is code-driven by feedback received from the PSD miswire and other detection systems. Annunciation could be through a variety or combination of audible alarms and visual display of system conditions and faults. Through the MICROPROCESSOR  11  algorithm-based code, every system condition and fault that occur in a PSD are defined. Said audible alarm or indication and visual display include such sounds as siren, buzz, or any distinct tone or pre-recorded and coded messages to annunciate specific system conditions or faults. The said visual display includes such as alphabetic, numeric, alpha-numeric or graphic display, colored or plain, to annunciate system conditions or faults through Light Emitting Diodes, Liquid Crystal Display, or other forms. Table 1 indicates some of the most common ways of annunciating system conditions and faults that occur in a PSD. This is only an illustration and not limiting but is intended to give certain possibilities within the scope of this invention. 
     The main components of the annunciation system is composed indiscriminately of all the PSD components for control and monitoring system conditions and faults as disclosed in the embodiments of this invention, and specifically the microprocessor which drives all the PSD&#39;s programmable functions. Monitored system conditions include voltage, current, wattage or energy consumption, power on or off, and electrical faults such as and including arc, overload, short circuit, ground and miswire. 
     A built-in or external speaker is used to annunciate different system conditions and the identifying names or codes for different faults that occur by use of sound alarms or pre-recorded messages. LED indicators or LCD displays with graphic, alphabetic, numeric and alpha-numeric display are used for visual indications of system conditions and faults. This invention, with proper interface also allows the visual and audible annunciation system to be transmitted and displayed on a remote location or panel through wired or wireless means. Remote operation of the TRIP and RESET functions may be done through the same interface. Exclusion applies for manual RESET  58  operation. 
     PSDs are designed to provide specific features and protection from different electrical faults that among others include arc, ground, short circuit, overload, surge, and miswire is an added feature. Although the PSDs made exemplary to the current invention are MICROPROCESSOR-based where all the monitoring, control and annunciation are code-driven and algorithm-based, the same system and method or principles disclosed in this invention also apply to non-MICROPROCESSOR-based PSDs with appropriate circuitry to adapt and accommodate them. 
     PSD code routines operate on a continuous loop to monitor system conditions, detect faults or system abnormalities, and interrupt the circuit when a fault occurs including miswire. Every electrical fault has specific characteristics or signatures which through comparative analysis, are identified. Through algorithm-based PSD code routines, a TRIP flag is initiated when a fault occurs which activates the TRIP circuit  13 , the TRIP SOLENOID  25 / 62 / 78  and ultimately the CONTACTOR CONTACTS  45 / 59 / 75  are opened, simultaneously activating audible and visual annunciations  17 / 18 . Through the PSD&#39;s MICROPROCESSOR code routines, every electrical fault is identified and corresponding visual and audible annunciations are activated when they occur. 
     PSDs differ in the methods and means of switching RESET and TRIP functions, however, the system and method of miswire protection of the current invention applies to all types with minor variation in the way they are applied. Among the most common and basic types of PSDs to which the current invention applies include the following:
         A) PSD utilizing a double-solenoid contactor with solenoid-actuated TRIP and RESET operation.   B) PSD utilizing a solenoid-actuated TRIP and a manually-operated RESET operation.   C) PSD utilizing a contactor with a single and common solenoid for TRIP and RESET operations with integrated locking and unlocking mechanisms.   D) PSD with a contactor using a single solenoid for TRIP and RESET operations with a magnetic latch to maintain RESET.       

     To better understand the system and method of miswire protection of a PSD described in (A) above with double-solenoid contactor where the TRIP and RESET mechanisms are operated by independent solenoids, different system conditions are described in details below:
         1. When the PSD is wired properly, main power supply ON and the contactor RESET BUTTON  70  is pressed:
           the DC POWER SUPPLY CIRCUIT  35  is connected through the BRIDGE RECTIFIER  33  and supplies the PSD control and monitoring circuit;   the LINE-NEUTRAL MISWIRE INDICATOR CIRCUIT  56  is connected to the NEUTRAL  2 / 54  on the LINE side of the PSD;   as soon as the RESET BUTTON  70  is pressed, the RESET signal is received by the MICROPROCESSOR  11  and executes its RESET code routine;   since the PSD is properly wired, the LINE-NEUTRAL INDICATOR CIRCUIT  56  feeds back to MICROPROCESSOR  11  for normal condition;   through the MICROPROCESSOR code routine, RESET COMMAND  42  is initiated, RESET SOLENOID  24  is activated by SCR  27 , the CONTACTOR CONTACTS  45  close, power is connected to the LOAD side of the PSD, and eventually the BRIDGE RECTIFIER  34  is connected to the LOAD-SIDE AC LINE;   the contactor auxiliary contacts NO  47  closes and NC  48  opens;   the TRIP/RESET INDICATOR CIRCUIT  14  feeds back signal to the MICROPROCESSOR  11  indicating normal condition;   by the PSD code routines the corresponding visual and audible indications for RESET condition are activated; and   the PSD operates normally and its code routines go on continuous loop monitoring system conditions and detecting electrical faults which include miswire.   
           2. When the PSD is wired properly, main power supply connected, CONTACTOR CONTACTS  45  are on RESET and the contactor TRIP BUTTON  71  is pressed:
           the DC POWER SUPPLY CIRCUIT  35  is supplied through the BRIDGE RECTIFIER  33  in parallel with BRIDGE RECTIFIER  34 , and supplies the PSD control and monitoring circuit;   the LINE-NEUTRAL MISWIRE INDICATOR CIRCUIT  56  is connected to the NEUTRAL  2 / 54  on the LINE side of the PSD;   all systems are in normal condition and the PSD executes its regular code routines before the TRIP BUTTON  71  is pressed;   as soon as the TRIP BUTTON  71  is pressed, the TRIP code routine is initiated, the TRIP circuit is powered up and the OPTOCOUPLER  32  pulses, triggering the SCR  28  to activate the TRIP SOLENOID  25  and open the CONTACTOR CONTACTS  45  where then the PSD is turned OFF.   the contactor auxiliary contacts  47  and  48  return to their normal positions; and   the TRIP/RESET INDICATOR CIRCUIT  14  feeds back signal to the MICROPROCESSOR  11  indicating TRIP position and by the PSD code routine activates the corresponding visual and audible indications.   
           3. When the PSD is miswired with LINE-SIDE and LOAD-SIDE wiring reversed, main power supply connected and the RESET BUTTON is pressed:
           the DC POWER SUPPLY CIRCUIT  35  is supplied through the BRIDGE RECTIFIER  34  and power to the PSD control and monitoring circuit is on;   before the RESET BUTTON  70  is pressed and with the power already connected on the LOAD side, the TRIP/RESET circuit  14  feeds back signal to MICROPROCESSOR  11  indicating the contactor is on RESET position although it is physically not; and meantime remains in the TRIP position;   as soon as the RESET BUTTON  70  is pressed, the PSD code routine starts, calling out the RESET code routine, activating the RESET SOLENOID  24 , however, since there is a pre-existing RESET position feedback from the TRIP/RESET INDICATOR CIRCUIT  14  as a result of the LINE-SIDE to LOAD-SIDE reverse wiring, by the PSD code routine it will be an indication that a miswire condition exists and the PSD will simultaneously call out a TRIP routine which will then activate the TRIP SOLENOID  25  through the TRIP/RESET CIRCUIT  13 , opening the CONTACTOR CONTACTS  45 , activating the corresponding audible and visual annunciations; and.   the PSD will continue to TRIP whenever the RESET BUTTON  70  is pressed until the miswire condition is corrected.   
           4. When the PSD is miswired with the LINE  1  and NEUTRAL  2  wiring reversed on the LINE side, main power supply on and when the RESET BUTTON  70  is pressed:
           the DC POWER SUPPLY CIRCUIT  35  is supplied through the BRIDGE RECTIFIER  33  and power to the PSD control and monitoring circuit is on;   before the RESET BUTTON  70  is pressed the LINE-NEUTRAL MISWIRE INDICATOR CIRCUIT  56  feeds back signal to MICROPROCESSOR  11  indicating a miswire condition since there is current flow to the LINE-NEUTRAL INDICATOR CIRCUIT  56  by having it connected across LINE and GROUND, and meantime the CONTACTOR  12  remains on the TRIP position;   as soon as the RESET BUTTON  70  is pressed, the PSD initiates its RESET code routine, activating the RESET SOLENOID  24 , however, since the feedback from the LINE-NEUTRAL MISWIRE INDICATOR CIRCUIT  56  as a result of the LINE-SIDE LINE-NEUTRAL reverse wiring indicates a miswire condition, the PSD will simultaneously call out a TRIP routine which will then activate the TRIP SOLENOID  25  through the TRIP/RESET CIRCUIT  13 , opening the CONTACTOR CONTACTS  45 , activating the corresponding audible and visual annunciations; and.   the PSD will continue to TRIP whenever the RESET BUTTON  70  is pressed until the miswire condition is corrected.   
           5. When the RESET BUTTON  70  is pressed, main power supply is on and when the PSD is miswired with the LINE  4  and NEUTRAL  5  wiring reversed on the LOAD side, the PSD operates as in normal condition. The LOAD side connections are reversible as far as the PSD is concerned and it will not be considered a miswire condition.   6. When the PSD is in RESET, main power supply on and in normal operating condition, and an electrical fault such as and including arc, ground, overload, short circuit occurs excluding miswire:
           by the PSD code routine, the fault is identified and verified;   a TRIP flag is initiated and the trip circuit is energized;   the TRIP SOLENOID  25  is activated, opening the CONTACTOR CONTACTS  45 ;   simultaneously, code routine calls for visual and/or audible annunciation;   visual annunciation is displayed through LED, graphic, alphabetic, numeric or alpha-numeric LCD of system condition or fault that occurred;   audible annunciation initiates simultaneously through a beep, buzz, bell or any desired sound, continuous or intermittent, including pre-recorded messages through the PSD&#39;s built-in speaker system;   the PSD will continue to TRIP whenever the RESET BUTTON  70  is pressed with the associated annunciation until the fault condition is corrected.   
               

     The system and method of miswire protection of a PSD described in (B) above with a solenoid-actuated TRIP and a manual RESET are described in details under normal conditions and different miswire situations:
         1. When the PSD is wired properly, main power supply connected and the contactor RESET BUTTON  70  is pressed:
           the DC POWER SUPPLY CIRCUIT  35  is supplied through the BRIDGE RECTIFIER  33  and supplies the PSD control and monitoring circuit;   the LINE-NEUTRAL INDICATOR CIRCUIT  56  is connected to the NEUTRAL  2 / 54  on the LINE side of the PSD;   as soon as the manual RESET BUTTON  58  is pressed, the MICROPROCESSOR executes its RESET code routine;   since the PSD is properly wired, the LINE-NEUTRAL INDICATOR CIRCUIT  56  feeds back normal conditions to MICROPROCESSOR  11 ;   simultaneously, the CONTACTOR CONTACTS  59  close and the LOAD side of the PSD is energized, eventually, the BRIDGE RECTIFIER  34  is connected to the LOAD-SIDE AC LINE;   simultaneously, the contactor auxiliary contacts NO  60  closes and NC  61  opens;   the TRIP/RESET INDICATOR CIRCUIT  14  feeds back signal to the MICROPROCESSOR  11  indicating normal condition;   by the PSD code routines, the corresponding visual and audible indications are activated; and   the PSD operates normally and the PSD code routines go on continuous loop monitoring system conditions and detecting electrical faults which include miswire.   
           2. When the PSD is wired properly, main power supply connected, CONTACTOR CONTACTS  59  are on RESET and the contactor TRIP BUTTON  71  is pressed:
           the DC POWER SUPPLY CIRCUIT  35  is powered through the BRIDGE RECTIFIER  33  in parallel with BRIDGE RECTIFIER  34 , and supplies the PSD control and monitoring circuit;   the LINE-NEUTRAL INDICATOR CIRCUIT  56  is connected to the NEUTRAL  2 / 54  on the LINE side of the PSD;   all systems are in normal condition and the PSD is on its regular code routines before the TRIP BUTTON is pressed;   as soon as the TRIP BUTTON  71  is pressed, the TRIP command is received by the MICROPROCESSOR and executes its TRIP code routine;   the TRIP CIRCUIT  72  is powered up and the OPTOCOUPLER  66  pulses, triggering the SCR  63  to activate the TRIP SOLENOID  62  and open the CONTACTOR CONTACTS  59  where then the PSD is turned OFF.   the contactor auxiliary contacts  60  and  61  return to their normal positions; and   the TRIP/RESET INDICATOR CIRCUIT  14  feeds back signal to the MICROPROCESSOR  11  indicating TRIP position and by the PSD code routines activate the corresponding visual and audible indications.   
           3. When the PSD is miswired with LINE and LOAD-SIDE wiring reversed, main power supply connected and the RESET BUTTON  58  is pressed:
           the DC POWER SUPPLY CIRCUIT  35  is supplied through the BRIDGE RECTIFIER  34  and power to the PSD control and monitoring circuit is on;   before the RESET BUTTON  58  is pressed and with the power already connected on the LOAD side, the TRIP/RESET circuit  14  feeds back signal to MICROPROCESSOR  11  indicating the contactor is on RESET position although it is physically not; and meantime PSD remains in the TRIP position;   as soon as the RESET BUTTON  58  is pressed, the CONTACTOR CONTACTS close and the PSD code routine starts however, since there is a pre-existing RESET position feedback from the TRIP/RESET INDICATOR CIRCUIT  14  as a result of the LINE-SIDE to LOAD-SIDE reverse wiring, by the PSD code routine it will be determined that a miswire condition exists and the PSD will simultaneously call out a TRIP routine which will then activate the TRIP SOLENOID  25  through the TRIP circuit  72 , opening the CONTACTOR CONTACTS  59 , activating the corresponding audible and visual annunciations; and.   the PSD will continue TRIP whenever the RESET BUTTON  58  is pressed and until the miswire condition is corrected.   
           4. When the PSD is miswired with the LINE and NEUTRAL wiring reversed on the LINE side, main power supply on and when the RESET BUTTON  58  is pressed:
           the DC POWER SUPPLY CIRCUIT  35  is supplied through the BRIDGE RECTIFIER  33  and power to the PSD control and monitoring circuit is on;   before the RESET BUTTON  58  is pressed, the LINE-NEUTRAL MISWIRE INDICATOR CIRCUIT  56  feeds back signal to MICROPROCESSOR  11  indicating the miswire condition, and meantime the CONTACTOR  57  remains on the TRIP position;   as soon as the RESET BUTTON  58  is pressed, the CONTACTOR CONTACTS  59  close and the LOAD side of the PSD is energized, and eventually, the BRIDGE RECTIFIER  34 ;   the PSD code routine starts, however, since there is a feedback from the LINE-NEUTRAL MISWIRE INDICATOR CIRCUIT  56  as a result of the LINE-SIDE LINE NEUTRAL reverse wiring, by the PSD code routine it will be determined that a miswire condition exists;   the PSD will simultaneously call out a TRIP routine which will then activate the TRIP SOLENOID  62  through the TRIP/RESET circuit  72 , opening the CONTACTOR CONTACTS  59 , activating the corresponding audible and visual annunciations; and.   the contactor auxiliary contacts NO  60  closes and NC  61  opens;   the PSD will continue to trip whenever the RESET BUTTON  70  is pressed and until the miswire condition is corrected.   
           5. When the RESET BUTTON  70  is pressed, main power supply is on and when the PSD is miswired with the LINE  4  and NEUTRAL  5  wiring reversed on the LOAD side, the PSD operates as in normal condition. The LOAD side connections are reversible as far as the PSD is concerned and it will not be considered a miswire condition.   6. When the PSD is in RESET, main power supply on and in normal operating condition, and an electrical fault such as and including arc, ground, overload, short circuit occurs including miswire:
           by the PSD code routine, the fault is identified and verified;   a TRIP flag is initiated and the trip circuit is energized;   the TRIP SOLENOID  62  is activated, opening the CONTACTOR CONTACTS  59 ;   simultaneously, code routine calls for visual and/or audible annunciation;   visual annunciation comes simultaneously through LED, graphic, alphabetic, numeric or alpha-numeric LCD of system condition or fault that occurred;   audible annunciation comes simultaneously through a beep, buzz, bell or any other sound, continuous or intermittent, including pre-recorded messages through the PSDs built-in speaker system.   the PSD will continue to trip whenever the RESET BUTTON  70  is pressed and until the fault condition is corrected.   
               

     The system and method of miswire protection of a PSD described in (C) above with a single-solenoid-actuated TRIP and RESET are described in details under normal conditions and different miswire situations:
         1. When the PSD is wired properly, main power supply connected and the contactor RESET BUTTON  70  is pressed:
           the DC POWER SUPPLY CIRCUIT  35  is supplied through the BRIDGE RECTIFIER  33  and supplies the PSD control and monitoring circuit;   the LINE-NEUTRAL INDICATOR CIRCUIT  56  is connected to the NEUTRAL on the LINE side of the PSD;   as soon as the RESET BUTTON  70  is pressed, the RESET signal is received by the MICROPROCESSOR  11  and executes its RESET code routine;   since the PSD is properly wired, the LINE-NEUTRAL INDICATOR CIRCUIT  56  feeds back normal conditions to MICROPROCESSOR  11 ;   the CONTACTOR CONTACTS  75  close and the LOAD side of the PSD is powered, and eventually the BRIDGE RECTIFIER  34 ;   simultaneously, the contactor auxiliary contacts NO  76  closes and NC  77  opens;   the TRIP/RESET INDICATOR CIRCUIT  14  feeds back signal to the MICROPROCESSOR  11  indicating normal condition;   by the PSD code routines, the corresponding visual and audible indications are activated; and   the PSD operates normally and the PSD code routines go on continuous loop monitoring system conditions and detecting electrical faults which include miswire.   
           2. When the PSD is wired properly, main power supply connected, CONTACTOR CONTACTS  75  are on RESET and the contactor TRIP BUTTON  71  is pressed:
           the DC POWER SUPPLY CIRCUIT  35  is supplied through the BRIDGE RECTIFIER  33  in parallel with BRIDGE RECTIFIER  34 , and supplies the PSD control and monitoring circuit;   the LINE-NEUTRAL INDICATOR CIRCUIT  56  is connected to the NEUTRAL  2 / 54  on the LINE side of the PSD;   all systems are in normal condition and the PSD is on its regular code routines before the TRIP BUTTON is pressed;   as soon as the TRIP BUTTON  71  is pressed, the TRIP command is received by the MICROPROCESSOR and executes its TRIP code routine;   the TRIP CIRCUIT  84  which in this type of contactor is the same as the RESET CIRCUIT  84  is powered up and the OPTOCOUPLER  82  pulses, triggering the SCR  79  to activate the TRIP and RESET SOLENOID  78  and open the CONTACTOR CONTACTS  75  where then the PSD is turned OFF.   the contactor auxiliary contacts  76  and  77  return to their normal positions; and   the TRIP/RESET INDICATOR CIRCUIT  14  feeds back signal to the MICROPROCESSOR  11  indicating TRIP position and by the PSD code routines activate the corresponding visual and audible indications.   
           3. When the PSD is miswired with LINE and LOAD-SIDE wiring reversed, main power supply connected and the RESET BUTTON  70  is pressed:
           the DC POWER SUPPLY CIRCUIT  35  is supplied through the BRIDGE RECTIFIER  34  and power to the PSD control and monitoring circuit is on;   before the RESET BUTTON  70  is pressed and with the power already connected on the LOAD side, the TRIP/RESET circuit  14  feeds back signal to MICROPROCESSOR  11  indicating the contactor is on RESET position although it is physically not; and meantime the PSD remains in the TRIP position;   as soon as the RESET BUTTON  70  is pressed, the CONTACTOR CONTACTS  75  close and the PSD code routine starts however, since there is a pre-existing RESET position feedback from the TRIP/RESET INDICATOR CIRCUIT  14  as a result of the LINE-SIDE to LOAD-SIDE reverse wiring, by the PSD code routine it will be determined that a miswire condition exists and the PSD will simultaneously call out a TRIP routine which will then activate the TRIP SOLENOID  78  through the TRIP circuit  84 , opening the CONTACTOR CONTACTS  75 , activating the corresponding audible and visual annunciations; and.   the PSD will continue to trip whenever the RESET BUTTON  70  is pressed and until the miswire condition is corrected.   
           4. When the PSD is miswired with the LINE and NEUTRAL wiring reversed on the LINE side, main power supply on and when the RESET BUTTON  70  is pressed:
           the DC POWER SUPPLY CIRCUIT  35  is supplied through the BRIDGE RECTIFIER  33  and power to the PSD control and monitoring circuit is on;   before the RESET BUTTON  70  is pressed, the LINE-NEUTRAL MISWIRE INDICATOR CIRCUIT  56  feeds back signal to MICROPROCESSOR  11  indicating the miswire condition, and meantime the contactor  74  remains on the TRIP position;   as soon as the RESET BUTTON  70  is pressed, the CONTACTOR CONTACTS  75  close and the LOAD side of the PSD is powered up, and eventually, the BRIDGE RECTIFIER  34 ;   the PSD code routine starts, however, since there is a feedback from the LINE-NEUTRAL MISWIRE INDICATOR CIRCUIT  56  as a result of the LINE-SIDE LINE-NEUTRAL reverse wiring, by the PSD code routines it will be determined that a miswire condition exist;   the PSD will simultaneously call out a TRIP routine which will then activate the TRIP SOLENOID  78  through the TRIP/RESET circuit  84 , opening the CONTACTOR CONTACTS  75 , activating the corresponding audible and visual annunciations;   the contactor auxiliary contacts NO  76  closes and NC  71  opens; and   the PSD will continue to TRIP whenever the RESET BUTTON is pressed and until the miswire condition is corrected.   
           5. When the RESET BUTTON  70  is pressed, main power supply is on and when the PSD is miswired with the LINE  4  and NEUTRAL  5  wiring reversed on the LOAD side, the PSD operates as in normal condition. The LOAD side connections are reversible and it will not be considered a miswire condition.   6. When the PSD is on RESET, main power supply on and in normal operating condition, and an electrical fault such as and including arc, ground, overload, short circuit occurs excluding miswire:
           by the PSD code routine, the fault is identified and verified;   a TRIP flag is initiated and the trip circuit is energized;   the TRIP SOLENOID  78  is activated, opening the CONTACTOR CONTACTS  75 ;   simultaneously, code routine calls for visual and/or audible annunciation;   visual annunciation comes simultaneously through LED, graphic, alphabetic, numeric or alpha-numeric LCD of system condition or fault that occurred;   audible annunciation comes simultaneously through a beep, buzz, bell or any other sound, continuous or intermittent, including pre-recorded messages through the PSDs built-in speaker system.   the PSD will continue to trip whenever the RESET BUTTON is pressed and until the fault condition is corrected.   
               

     The system and method of miswire protection of a PSD described in (D) above with a single-solenoid-actuated TRIP and RESET using a latching mechanism to maintain RESET position follows the same principles as (B) above except that the a magnetic latch is used in lieu of MANUAL RESET  58 . Without limitations, the other principles described in the current invention may also be applied. 
     While the invention has been described in connection with a preferred embodiment, it is not intended to limit the scope of the invention to the particular form set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.