Abstract:
An electrical distribution system for selectively connecting an electrical power source to load devices comprises a panelboard having a plurality of load circuit positions. A remote operated relay is mountable in the panelboard in an adjacent pair of the load circuit positions comprising a multipole switching device, and a switch control for controlling the switching device, the switch control comprising a control circuit for operating the switching device responsive to control commands and a communication circuit for receiving control commands. An input/output (I/O) controller is mounted in the panelboard for controlling operation of the remote operated relay, the I/O controller comprising a programmed controller for generating the control commands for commanding operation of the remote operated relay, the control system including a communication circuit for communication with the remote operated relay communication circuit.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority of provisional application No. 60/826,623 filed Sep. 22, 2006, the contents of which is incorporated by reference herein. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to residential and commercial electrical power distribution panels and components, and more particularly, to a multipole remote operated relay in an electrical power distribution system. 
     BACKGROUND OF THE INVENTION 
     Circuit breaker panels are used to protect electrical circuitry from damage due to an overcurrent condition, such as an overload, a relatively high level short circuit, or a ground fault condition. To perform that function, circuit breaker panels include circuit breakers that typically contain a switch unit and a trip unit. The switch unit is coupled to the electrical circuitry (i.e., lines and loads) such that it can open or close the electrical path of the electrical circuitry. The switch unit includes a pair of separable contacts per phase, a pivoting contact arm per phase, an operating mechanism, and an operating handle. 
     In the overcurrent condition, all the pairs of separable contacts are disengaged or tripped, opening the electrical circuitry. When the overcurrent condition is no longer present, the circuit breaker can be reset such that all the pairs of separable contacts are engaged, closing the electrical circuitry. 
     In addition to manual overcurrent protection via the operating handle, automatic overcurrent protection is also provided via the trip unit. The trip unit, coupled to the switch unit, senses the electrical circuitry for the overcurrent condition and automatically trips the circuit breaker. When the overcurrent condition is sensed, a tripping mechanism included in the trip unit actuates the operating mechanism, thereby disengaging the first contact from the second contact for each phase. Typically, the operating handle is coupled to the operating mechanism such that when the tripping mechanism actuates the operating mechanism to separate the contacts, the operating handle also moves to a tripped position. 
     Switchgear and switchboard are general terms used to refer to electrical equipment including metal enclosures that house switching and interrupting devices such as fuses, circuit breakers and relays, along with associated control, instrumentation and metering devices. The enclosures also typically include devices such as bus bars, inner connections and supporting structures (referred to generally herein as “panels”) used for the distribution of electrical power. Such electrical equipment can be maintained in a building such as a factory or commercial establishment, or it can be maintained outside of such facilities and exposed to environmental weather conditions. Typically, hinge doors or covers are provided on the front of the switchgear or switchboard sections for access to the devices contained therein. 
     In addition to electrical distribution and the protection of circuitry from overcurrent conditions, components have been added to panels for the control of electrical power to loads connected to circuit breakers. For example, components have been used to control electrical power for lighting. 
     One system used for controlling electrical power to loads utilizes a remote-operated circuit breaker system. In such a system, the switch unit of the circuit breaker operates not only in response to an overcurrent condition, but also in response to a signal received from a control unit separate from the circuit breaker. The circuit breaker is specially constructed for use as a remote-operated circuit breaker, and contains a motor for actuating the switch unit. 
     In an exemplary remote-operated circuit breaker system, a control unit is installed on the panel and is hard-wired to the remote-operated circuit breaker through a control bus. When the switch unit of the circuit breaker is to be closed or opened, an operating current is applied to or removed from the circuit breaker motor directly by the control panel. Additional, separate conductors are provided in the bus for feedback information such as contact confirmation, etc., for each circuit breaker position in the panel. The control unit contains electronics for separately applying and removing the operating current to the circuit breakers installed in particular circuit breaker positions in the panel. The panel control unit also has electronics for checking the state of the circuit breaker, diagnostics, etc. One advantage of that system is that the individual circuit breakers can be addressed according to their positions in the panel. 
     Operation of remote operated circuit breakers becomes more difficult when the need exists for a two or three pole unit to provide multiple sets of contacts. A plurality of single pole devices may be operated at the same time to simulate a multipole device. However, timing issues exist with such a configuration. Also, if one of the devices fails or is operated oppositely to that intended improper load operation could result. Moreover, separate control circuitry is necessary for each of the individual single pole units. Previously, such circuitry has been external to the switching device due to component size and the amount of power required. Locating communication circuitry outside the switching device necessitates the circuitry always being present in the panelboard even if the switching device is not. 
     The present invention is directed to a multipole relay device. 
     SUMMARY OF THE INVENTION 
     In accordance with the invention, there is provided a multipole remote operated relay in an electrical power distribution system. 
     In accordance with one aspect of the invention there is disclosed a remote operated device for selectively distributing electrical power from an electrical power source to load circuits comprising a housing mountable in a distribution panel. A multipole switching device is in the housing. A switch control in the housing controls the switching device. The switch control comprises a control circuit for operating the switching device responsive to control commands and a communication circuit for receiving control commands from a remote controller. 
     It is a feature of the invention that the multipole switching device comprises first and second relays. 
     It is another feature of the invention that the first and second relays are parallel connected to the control circuit. The first and second relays may be mechanically linked. 
     It is a further feature of the invention that the multipole switching device comprises first and second magnetically held solenoids. The control circuit may develop relatively short duration latch and unlatch signals to the solenoids. Duration of the latch signal is greater than duration of the unlatch signal. 
     It is still another feature of the invention to use a sensing devise for sensing position of the switching devices. The multipole switching device may comprises first and second relays and the sensing device may comprise auxiliary contacts. 
     There is disclosed in accordance with another aspect of the invention an electrical distribution system for selectively connecting an electrical power source to load devices, comprising a panelboard having a plurality of load circuit positions. A remote operated relay is mountable in the panelboard in an adjacent pair of the load circuit positions comprising a multipole switching device, and a switch control for controlling the switching device, the switch control comprising a control circuit for operating the switching device responsive to control commands and a communication circuit for receiving control commands. An input/output (I/O) controller is mounted in the panelboard for controlling operation of the remote operated relay, the I/O controller comprising a programmed controller for generating the control commands for commanding operation of the remote operated relay, the control system including a communication circuit for communication with the remote operated relay communication circuit. 
     Further features and advantages of the invention will be readily apparent from the specification and the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an elevation view of a power distribution panel according to the invention; 
         FIG. 2  is a block diagram illustrating pairs of circuit breakers and remote operated devices of the power distribution panel of  FIG. 1 ; 
         FIG. 3  is a block diagram of the power distribution panel of  FIG. 1 ; 
         FIG. 4  is an expanded schematic/block diagram of the power distribution panel of  FIG. 1 ; 
         FIG. 5  is a basic block diagram of a multipole remote operated relay in accordance with the invention; and 
         FIG. 6  is a detailed block diagram of the multipole remote operated relay of  FIG. 5 ; and 
         FIG. 7  is a perspective view illustrating mechanical linking of solenoids in the multipole remote operated relay of  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     An electrical distribution system, such as an integrated lighting control system, in accordance with the invention permits a user to control power circuits typically used for lighting, as well as circuits for resistive heating or air conditioning, using multipole remote operated relays. The electrical distribution system may be as is generally described in U.S. application Ser. No. 11/519,727, filed Sep. 12, 2006, the specification of which is incorporated by reference herein. 
     Referring to  FIG. 1 , a lighting control system in accordance with the invention comprises a lighting control panel  100 . The panel  100  may comprise a Siemens type P1 panelboard, although the invention is not limited to such a configuration. Line power enters the panel  100  through power source cables  102  connected to a source of power  104 . Line power may, for example, be a three phase 480Y277, 240 or 120 VAC power source, as is conventional. The cables  102  are electrically connected to an input side of a main breaker  106 . The main breaker  106  distributes line power to individual circuit breakers  108  in a conventional manner. How the power is distributed depends on design of the individual circuit breakers  108 , as will be apparent to those skilled in the art. The power is distributed to the line side of individual circuit breakers  108 . The panel  100  may be configured to accept up to forty two individual circuit breakers  108 , although only thirty are shown in the embodiment of  FIG. 1 . Each circuit breaker may be of conventional construction and may be, for example, a Siemens BQD circuit breaker. Each circuit breaker  108  includes a line terminal  108 A receiving power from the main breaker  106  and a load terminal  108 B conventionally used for connecting to a load circuit. 
     For simplicity of description, when a device such as a circuit breaker  108  is described generally herein the device is referenced without any hyphenated suffix. Conversely, if a specific one of the devices is described it is referenced with a hyphenated suffix, such as  108 - 1 . 
     In accordance with the invention, each load circuit to be controlled also has a remote operated device  110 , such as a relay, a meter or a dimmer. The term remote operated device as used herein includes any other devices that controls, monitors or may otherwise be used in a load circuit, in accordance with the invention. While in a preferred embodiment, the remote operated device  110  is a separate component from the circuit breaker  108 , the term “remote operated device” as used herein encompasses devices integral with the circuit breaker. The remote operated devices  110  are also connected to data rails  112 A and  112 B. A panel controller  114  controls the remote operated devices  110  through connections provided via the data rails  112 A and  112 B, as discussed below. 
     The remote operated device  110  includes a housing  110 H encasing an auxiliary set of contacts that can be remotely operated to open and close a lighting circuit. The device  110  is attached to the load side of a circuit breaker  108  within a panel  100  using a conductor tab, i.e, the terminal  110 A, inserted into the breaker lug  108 B. The load terminal  110 B comprises a lug of the same size as the breaker lug  108 B for connecting to a wire to be connected to the load device. The device housing  110 H is configured to mount in a Siemens type P1 panelboard, although the invention is not limited to such a configuration. 
     Referring to  FIG. 2 , a block diagram illustrates four circuit breakers  108 - 1 ,  108 - 2 ,  108 - 3  and  108 - 4 , and respective associated remote operated devices  110 - 1 ,  110 - 2 ,  110 - 3  and  110 - 4 . In the illustrated embodiment, the first device  110 - 1  comprises a relay, the second device  110 - 2  comprises a breaker, the third device  110 - 3  comprises a current transformer, and the fourth device  110 - 4  comprises a dimmer. As is apparent, any combination of these remote operated devices  110  could be used. Each remote operated device  110  includes an input terminal  110 A electrically connected to the associated circuit breaker load terminal  108 B, and an output terminal  110 B for connection to a load device. 
     Referring to  FIG. 3 , a block diagram of the lighting control panel  100  is illustrated. Power from the lines  102  is provided via an isolation transformer  116 , power switch  118  and fuse  120  to a switching power supply  122 . The panel controller  114  comprises an input/output (I/O) controller  124  and optionally a system controller  126 . The power supply  122  provides isolated power to all of the control components including the I/O controller board  124 , the system controller  126 , and the remote operated devices  110 , see  FIG. 1 , via the data rails  112 A and  112 B. The I/O controller  124  and system controller  126  each have DC-DC converters deriving regulated DC voltage levels as required from the main DC output of the power supply  122 . The power supply  122  also provides 24 volts to the remote operated devices  110 . The system controller  126  is operatively connected to a touch screen  128  and an LCD  130 . 
     In one embodiment of the invention, shown in  FIG. 4 , the panel controller  114  functions as a single panel stand alone system. The I/O controller  124  supplies power and control signals through the rails  112 A and  112 B to the remote operated devices, four of which,  110 - 1 ,  110 - 21 ,  110 - 22  and  110 - 42 , are illustrated. A user interface and high level scheduling and control are provided by the system controller  126 . 
     The I/O controller  124  provides discrete inputs to the controller  114  from dry contact switches, such as wall switches, (not shown) which can be connected to discrete input terminals  140 . The terminals  140  are organized as two inputs and a common. The inputs to the terminals  140  are detected by dry contact I/O logic  142 . A selector logic block  144  generates selector line signals and serial communications to the remote operated devices  110  via the data rails  112 . The logic blocks  142  and  144  are operatively associated with a microprocessor or microcontroller  146 . A TP-UART integrated circuit  148  provides an EIB (European Installation Bus) interface. A connector  149  allows mating directly to the system controller  126  via a cable  150 . 
     The system controller  126  provides the user with an application to implement lighting schedules, organize devices into logical groups, manage the inputs, and obtain status information. The system controller  126  includes a microprocessor  152  operatively connected to a user interface  154  in the form of an integrated touch screen  128  and LCD  130 , see Fig. H. The microprocessor  152  is also connected to memory devices  156  and an ethernet controller  158 . A TP-UART circuit  160  provides an EIB interface while additional interfaces are provided via an analog modem  162  and RS  485  interface circuit  164 . A connector  162  is provided for connection to the cable  150 . 
     Referring again to  FIG. 2 , a data rail  112  is illustrated schematically. The data rail  112  is mechanically attached directly to the interior of the lighting control panel  100 . The data rail  112  comprises a shielded communication bus including a ribbon connector  178  having twenty-five to twenty-nine wires to be routed to the I/O controller board  124 . The ribbon connector  178  typically has twenty-six wires, two for power connection, two for ground connection, one for the serial line and up to twenty-one select lines, one for each remote operated device  110 . Each data rail  112  provides a barrier to isolate the class  1  load wires from the class  2  signal wires used to manage the devices  110 . The data rails  112  will connect to each device  110  via a connector that extends out of the device  110 . The wires are connected to a printed circuit board  180  included traces defined as follows. A power trace  182  provides 24 volt DC power to each remote operated device  110 . A common trace  184  provides a ground to each remote operated device  110 . A serial interface trace  186  provides serial communication to each of the remote operated devices  110 . A plurality of select line traces, four of which  188 - 1 ,  188 - 2 ,  188 - 3  and  188 - 4  are illustrated, are provided, one for each remote operated device  110 . Each remote operated device  110  includes a four wire cable  190  for connection to the data rail  112 . The four wires comprise a select line  191  connected to one of the select traces  188 , a serial interface line  192  connected to the serial interface trace  186 , a neutral wire  193  connected to the common trace  184  and a power wire  194  connected to the power trace  182 . 
     In accordance with the invention, a unique select line is assigned to each breaker  108 /remote operated device  110  pair positioned within the lighting control panel  100 . Select lines are used by the I/O controller  124  to select single remote operated devices to communicate via the serial interface trace  186 . For example, when the first select line  188 - 1  is asserted, the first remote operated device  110 - 1  listens for messages on the serial interface line  186 . Conversely, messages on the serial interface  186  are ignored if the first select line  188 - 1  is not asserted. A response by any of the remote operated devices  110  to a serial command is therefore conditional on whether its particular select line is asserted. The term “asserted”, as used herein, means one state of a signal designated to cause the remote operated device to listen for messages. In a preferred embodiment, the select line has “high” and “low” states, the high state being the asserted state. 
     The remote operated device  110 , in the form of a relay, allows remote switching of an electrical branch load. The device  110  is designed to fit inside a standard electrical panel board with up to forty-two branch circuit breakers  108 . The device  110  is an accessory to a branch circuit breaker  108  allowing repetitive switching of the load without effecting operation of the circuit breaker  108 . 
     The remote operator device  110  requires a means to receive command signals to open or close and to report back successful operation or device status. Also required is a means to drive opening and closing of the switch mechanism contacts. In accordance with the invention, the remote operator device is a multipole relay that uses two magnetically held solenoids as an actuator device and one electronic circuit board similar to a single pole device. With this design, electronic control circuitry is located inside the switching device itself. Only one circuit is needed to operate both actuators. The use of two magnetically held solenoids or “mag latches” as switching actuators results in very low energy requirements, requires short duration pulses to change position (measured in milliseconds), provides accurate and repeatable timing and requires that the control must reverse voltage polarity. 
       FIG. 5  illustrates a basic block diagram for multipole load switching. The remote operated device, in the form of a multipole remote operated relay  110 -M includes two housings  110 H- 1  and  110 H- 2  connected together to form a two pole housing, as generally illustrated. The two pole housing occupies two positions in the panel  100 . A control circuit  480  in the first housing  110 H- 1  is connected to the cable  190 . The control circuit  480  drives two control relays CR 1  and CR 2 , in the respective housings  110 H- 1  and  110 H- 2 , each having a normally open contact connected between terminals  110 A- 1  and  110 B- 1 , and  110 A- 2  and  110 B- 2 , respectively. A sensor  484  senses status of the relays CR 1  and CR 2  and is connected to the control circuit  480 . As such, the control circuit  480  controls operation of the contacts CR 1  and CR 2  to selectively electrically connect a load L to the breakers  108 - 1  and  108 - 2 , and thus to power the load L. 
       FIG. 6  illustrates a detailed block diagram of the remote operated device  110 -M. Connection to the data rail  112  is through a four wire port  500 . The port  500  includes a positive supply voltage and ground, a serial communication line, and a select line, as discussed above. The supply voltage and ground are fed to a power supply  502  to generate voltage as needed for a microcontroller  504  and other circuits. A communication driver circuit  506  is used to isolate and drive a single wire serial communication line between the microcontroller  504  and the port  500  and thus the data rail  112 . As discussed above, the single wire connection to each remote operated device  110  and to the I/O controller  124  is used to transmit and receive commands and data. This provides necessary isolation and protection. In the event of an individual device failure, the remainder of the devices continue to operate properly. The select line from the port  500  is buffered in a line buffer  508  and connected to the microcontroller  504 . This select line is used to enable or disable communications to and from the remote operated device  110 -M. By selecting more than one remote operated device, the I/O controller  124  can send commands or messages to multiple devices  110  at the same time, reducing traffic on the serial communication bus. 
     The microcontroller  504  comprises a conventional microcontroller and associated memory  504 M, the memory storing software to run in the microcontroller  504 . 
     The microcontroller  504  has OPEN and CLOSE lines to an actuator drive circuit  510 . The control relays CR 1  and CR 2  in the illustrated embodiment of the invention comprise magnetically held solenoids including a primary actuator coil  512  and a secondary actuator coil  514 , see also  FIG. 7 , connected in parallel to the actuator drive circuit  510 . The actuator drive circuit  510  provides current for both coils  512  and  514 . An OPEN signal causes the drive circuit to apply negative voltage to the actuator coils for a short period of time (about 10 to 30 milliseconds). This causes actuator plungers  530  and  532  to pull-in and become magnetically latched or held in the open position to open the contacts CR 1  and CR 2 , see  FIG. 5 , in a conventional manner. The plungers  530  and  532  are mechanically linked by a tie bar  534 . Power is then removed from the coils  512  and  514 . A CLOSE signal from the microcontroller  504  causes the drive circuit  510  to apply a positive voltage to the actuator coils  512  and  514  for a shorter period of time (about 2 to 3 milliseconds). This period of time is sufficient for the actuator plungers  530  and  532  to become unlatched or released and springs force them to the closed position to close the contacts CR 1  and CR 2 , see  FIG. 5 . Again, power is then removed from the coils  512  and  514 . Since the actuators are stable in both the open and closed positions, energy is only required to change position. This results in low energy solution even with two coils in parallel. Also included in the actuator drive circuit  510  is protection from both open and closed signals applied at the same time, which could result in a short circuit of the power supply  502 . In the case of a three pole device, the actuators are located in the outer poles and a tie bar actuates the center pole. 
     Feedback for actuator plunger positions is provided by the sensor  484  in the form of two auxiliary position switches, a primary position switch  516  and a secondary position switch  518 , such as auxiliary relay contacts. In the event of a three pole device, the secondary auxiliary switch is actually two switches wired in parallel so that both poles have to be open to indicate open to the microcontroller  504 . The signals are buffered in respective input buffers  520  and  522  and then connected to the microcontroller  504 . The microcontroller  504  uses the feedback information to respond to an I/O controller request for status or to retry a failed open or close attempt. 
     Additionally, the microcontroller  504  can send signals to various types of status indicators  524  such as LEDs to show open, closed, communications OK, operating properly, low voltage, etc. A programming port  526  can be used to program or update the microcontroller software or to load parameters such as on/off pulse rates or to troubleshoot the device  110 . 
     Thus, in accordance with the invention there is provided a multipole remote operated relay in an electrical power distribution system. 
     The present invention has been described with respect to flowcharts and block diagrams. It will be understood that each block of the flowchart and block diagrams can be implemented by computer program instructions. These program instructions may be provided to a processor to produce a machine, such that the instructions which execute on the processor create means for implementing the functions specified in the blocks. The computer program instructions may be executed by a processor to cause a series of operational steps to be performed by the processor to produce a computer implemented process such that the instructions which execute on the processor provide steps for implementing the functions specified in the blocks. Accordingly, the illustrations support combinations of means for performing a specified function and combinations of steps for performing the specified functions. It will also be understood that each block and combination of blocks can be implemented by special purpose hardware-based systems which perform the specified functions or steps, or combinations of special purpose hardware and computer instructions.