Abstract:
A power factor correction device ( 1 ) having one or more capacitors ( 10 ) in which the capacitance can be varied depending on the amount of power factor correction that is needed for a given application. Disconnect blocks ( 16 ) having internal bridging bars ( 19 ) are used to activate and deactivate fixed-value capacitors ( 13 ) and/or variable capacitance capacitors ( 12 ) within the device. The device may use variable capacitance capacitors either alone or in combination with fixed-value capacitors depending on the size of an electrical circuit. In addition to reducing electrical usage by correcting power factor, surge protection is promoted through the use of surge arresters ( 18 ).

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application No. 61/168,821, filed Apr. 13, 2009. The patent application identified above is incorporated here by reference in its entirety to provide continuity of disclosure. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    This invention relates to energy saving devices, more particularly, an energy savings device that corrects power factor in an electrical circuit through the use of variable capacitors that may be adjusted to lower or raise the level of capacitance depending on how much or how little power factor correction is needed in a particular electrical circuit. 
         [0003]    In residential or commercial establishments, the loads served by electric utility companies are generally primarily resistive, such as a space heater, or primarily inductive, such as a motor. The inductive loads draw a combination of kilowatts (real or inductive power) and kilovars (reactive power). Capacitors are a static source of kilovars. 
         [0004]    Capacitors installed at inductive loads provide a number of benefits: reduced electrical energy consumption, reduced line current, increased voltage at the load, better voltage regulation and lower energy losses. These benefits are accomplished by installing sufficiently sized capacitors at the load to bring power factor to just under unity. Power factor is equal to killowatts divided by kilovars. 
         [0005]    Current power factor correction devices use capacitors with fixed levels of capacitance, commonly measured in microfarads (uF). The size of a capacitor to be used in any application is determined at the time of installation. Current fixed-value power factor correction devices do not provide a user with the ability to adjust the level of capacitance when changes in the electrical circuit occur. However, power factor in an electrical circuit may change over time due to the addition or removal of electrical devices from the electrical circuit. In situations such as these, a fixed-value power factor correction device has to be removed from the electrical circuit and replaced with a different unit having the correct fixed capacitance level. The replacement of a fixed-value power factor correction device can be very expensive. For this reason, capacitors are not used to optimize load factor as widely as they might be. 
         [0006]    Although there have been attempts to create power factor correction devices having adjustable levels of capacitance in the past, such attempts could not be accomplished manually and required computerization. Past devices used standard on/off switches, on/off buttons, etc. to activate and deactivate fixed-value capacitors and/or variable capacitance capacitors within the device. However, the on/off switches, on/off buttons, etc. could not handle the electrical loads of common single phase or three phase applications and would short out very easily, thereby causing the power factor correction device to be inoperable. 
         [0007]    Thus, a need exists for a power factor correction device with adjustable capacitance that allows a user to adjust the level of capacitance of the power factor correction device during installation and when there are changes in the induction load electrical circuit. In addition, a need exists for a power factor correction device having a means for activating and deactivating fixed-value capacitors and/or variable capacitance capacitors within the device that is able to handle electrical loads commonly found in single phase and three phase applications. 
         [0008]    The relevant prior art includes the following references: 
         [0000]    
       
         
               
               
               
             
           
               
                   
               
               
                 Patent No. 
                   
                   
               
               
                 (U.S. unless stated otherwise) 
                 Inventor 
                 Issue/Publication Date 
               
               
                   
               
             
             
               
                 2009/0310272 
                 Howell 
                 Dec. 17, 2009 
               
               
                 3,300,712 
                 Segsworth 
                 Jan. 24, 1967 
               
               
                 3,859,564 
                 Zulaski 
                 Jan. 07, 1975 
               
               
                 3,900,772 
                 Anderl et al. 
                 Aug. 19, 1975 
               
               
                 5,138,519 
                 Stockman 
                 Aug. 11, 1992 
               
               
                 5,227,962 
                 Marsh 
                 Jul. 13, 1993 
               
               
                 5,287,288 
                 Brennen, et al. 
                 Feb. 15, 1994 
               
               
                 5,510,689 
                 Lipo et al. 
                 Apr. 23, 1996 
               
               
                 5,627,737 
                 Maekawa et al. 
                 May 06, 1997 
               
               
                 5,638,265 
                 Gabor 
                 Jun. 10, 1997 
               
               
                 5,793,623 
                 Kawashima et al. 
                 Aug. 11, 1998 
               
               
                 5,878,584 
                 Sasaki et al. 
                 Mar. 09, 1999 
               
               
                 6,008,548 
                 Fenner et al. 
                 Dec. 28, 1999 
               
               
                 6,191,676 
                 Gabor 
                 Feb. 20, 2001 
               
               
                 2002/0089373 
                 Shashoua 
                 Jul. 11, 2002 
               
               
                 6,462,492 
                 Sakamoto et al. 
                 Oct. 08, 2002 
               
               
                 6,573,691 
                 Ma et al. 
                 Jun. 03, 2003 
               
               
                 6,747,373 
                 Hu et al. 
                 Jun. 08, 2004 
               
               
                 6,876,178 
                 Wu et al. 
                 Apr. 05, 2005 
               
               
                 7,092,232 
                 Yamagata et al. 
                 Aug. 15, 2006 
               
               
                 7,203,053 
                 Stockman 
                 May 10, 2007 
               
               
                   
               
             
          
         
       
     
       SUMMARY OF THE INVENTION 
       [0009]    The primary objects of the present invention are to provide a power factor correction device in which the capacitance level is adjustable. 
         [0010]    Another object of the present invention is to provide a power factor correction device having a means for activating and deactivating fixed-value capacitors and/or variable capacitance capacitors within the device is able to handle electrical loads commonly found in single phase and three phase applications. 
         [0011]    An even further object of the present invention is to provide a power factor correction device that optimizes power factor in an electrical circuit. 
         [0012]    Another object of the present invention is to provide a power factor correction device that reduces kilowatt usage. 
         [0013]    An even further object of the present invention is to provide a power factor correction device that provides surge protection. 
         [0014]    Another object of the present invention is to provide a power factor correction device that provides brown-out protection. 
         [0015]    An even further object of the present invention is to provide a power factor correction device that extends the life span of motors and appliances. 
         [0016]    The present invention fulfills the above and other objects by providing a power factor correction device that saves electrical energy by optimizing the power factor in an electrical circuit through the use of capacitors. 
         [0017]    Power factor optimization is a technique used to improve the relationship between inductive power and reactive power as follows: 
         [0000]    
       
         
           
             
               power 
                
               
                   
               
                
               factor 
                
               
                   
               
                
               
                 ( 
                 pf 
                 ) 
               
             
             = 
             
               
                 kilowatts 
                  
                 
                     
                 
                  
                 
                   ( 
                   
                     working 
                      
                     
                       / 
                     
                      
                     real 
                      
                     
                       / 
                     
                      
                     inductive 
                      
                     
                         
                     
                      
                     power 
                   
                   ) 
                 
               
               
                 kilovars 
                  
                 
                     
                 
                  
                 
                   ( 
                   
                     apparent 
                      
                     
                       / 
                     
                      
                     total 
                      
                     
                         
                     
                      
                     reactive 
                      
                     
                         
                     
                      
                     power 
                   
                   ) 
                 
               
             
           
         
       
     
         [0000]    Capacitors are static sources of kilovars or reactive power and can be installed at a circuit breaker box or switch of inductive equipment, such as air conditioner motors, to reduce amperage usage and adjust the power factor as close as possible to unity, i.e., 1. In this manner the equipment is provided only the power necessary to operate optimally. As is typical of energy saving devices, the present device uses capacitors, however, unlike prior devices, the present device uses capacitors in which the capacitance can be varied depending on the amount of power factor correction that is needed for a given application. In addition, the present invention provides a means for activating and deactivating fixed-value capacitors and/or variable capacitance capacitors within the device in which said means is able to handle electrical loads commonly found in single phase and three phase applications. Specifically, the device uses one or more disconnect blocks positioned between one or more capacitors and the electrical circuit. The disconnect blocks each comprise an internal bridging bar that is operable by a locking means for manually connecting or disconnecting a capacitor or portion of a capacitor to or from the electrical circuit. The device may use variable capacitance capacitors either alone or in combination with fixed-value capacitors depending on the size of an electrical circuit. 
         [0018]    In addition to reducing electrical usage, surge protection is promoted through the use of surge arresters, also called metal oxide varistors (MOVs) or transient voltage surge suppressors (TVSS) that are located in the power factor correction device. The surge arresters provide surge, lightning, and brown-out protection to the electrical circuit. 
         [0019]    The above and other objects, features and advantages of the present invention should become even more readily apparent to those skilled in the art upon a reading of the following detailed description in conjunction with the drawings wherein there is shown and described illustrative embodiments of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    In the following detailed description, reference will be made to the attached drawings in which: 
           [0021]      FIG. 1  is a front perspective view of the outside of a power factor correction device of the present invention; 
           [0022]      FIG. 2  is a front perspective view of the inside of a power factor correction device of the present invention for three phase applications; 
           [0023]      FIG. 3  is a front perspective view of the inside of a power factor correction device of the present invention for single phase applications; 
           [0024]      FIG. 4  is a perspective side view of a disconnect block of the present invention; and 
           [0025]      FIG. 5  is a top view showing discreet capacitive cells of a variable capacitance capacitor. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0026]    For purposes of describing the preferred embodiment, the terminology used in reference to the numbered components in the drawings is as follows: 
         [0000]    
       
         
               
               
             
           
               
                   
               
             
             
               
                 1. 
                 device 
               
               
                 2. 
                 enclosure 
               
               
                 3. 
                 rear wall 
               
               
                 4. 
                 side wall 
               
               
                 5. 
                 front cover 
               
               
                 6. 
                 securing means 
               
               
                 7. 
                 knockout hole 
               
               
                 8. 
                 on/off status lamp 
               
               
                 9. 
                 surge arrester status lamp 
               
               
                 10. 
                 capacitor 
               
               
                 11. 
                 holding means 
               
               
                 12. 
                 variable capacitance capacitor 
               
               
                 13. 
                 fixed-value capacitor 
               
               
                 14. 
                 din rail 
               
               
                 15. 
                 terminal block 
               
               
                 16. 
                 disconnect block 
               
               
                 17. 
                 circuit breaker 
               
               
                 18. 
                 surge arrester 
               
               
                 19. 
                 bridging bar 
               
               
                 20. 
                 circuit bar 
               
               
                 21. 
                 locking means 
               
               
                 22. 
                 discreet capacitive cell 
               
               
                 23. 
                 individual tap 
               
               
                 24. 
                 common terminal 
               
               
                   
               
             
          
         
       
     
         [0027]    With reference to  FIG. 1 , a front perspective view of the outside of a power factor correction device  1  of the present invention is shown. The power factor correction device  1  preferably has an outer enclosure  2  having a rear wall  3 , side walls  4 , a front cover  5 , a securing means  6 , such as a latch, screw, etc., for securing the front cover  5  to the enclosure  2  and at least one knockout hole  7  for connecting the device to an electrical service, preferably a circuit breaker switch or switch at an electrical panel or meter. An on/off status lamp  8 , which is preferably green, located on the enclosure  2  visually indicates to a user that the device is activated when the on/off status lamp  8  is illuminated. Alternatively, the on/off status lamp  8  visually indicates to a user that the device has been deactivated when the on/off status lamp  8  is not illuminated. An surge arrester status lamp  9 , which is preferably red, located on the enclosure  2  visually indicates to a user that an at least one surge arrester  18  (as shown in  FIGS. 2 and 3 ) located inside the enclosure  2  has been tripped when the surge arrester status lamp  8  is illuminated. 
         [0028]    With reference to  FIGS. 2 and 3 , internal views of power factor correction devices  1  of the present invention for use in a three phase application and a single phase application, respectively, are shown. At least one capacitor  10  is located inside the enclosure  2  and preferably held in place by at least one holding means  11 , such as a bracket, nut and bolt, etc. The number and capacitance level of the at least one capacitor  10  depend on the electrical demand of an application and if the application is a single phase or three-phase application. The at least one capacitor  10  may have at least one variable capacitance capacitor  12  or a combination of at least one variable capacitance capacitor  12  and at least one fixed-value capacitor  13  located therein. The type and combination of capacitors  10  depends on the electrical demand of an application. A din rail  14  mounted on the rear wall  3  of the enclosure  2  provides an attachment point for at least one terminal block  15 , at least one disconnect block  16 , at least one circuit breaker  17  and at least one surge arrester  18 . The at least one disconnect block  16  further comprises an internal bridging bar  19  (shown further in  FIG. 4 ) that allows a user to manually activate or deactivate the at least one capacitor  10  or individual discreet capacitive cells  22  of a variable capacitor  12  (shown further in  FIG. 5 ), thereby allowing a user to adjust the capacitance level of the device  1 . The at least one terminal block  15  is grouped to provide a point of connection for an electrical circuit from the at least one circuit breaker  17 , the at least one disconnect block  16 , the at least one capacitor  10  and the at least one surge arrester  18 . The at least one circuit breaker  17  allows a user to activate or deactivate the device  2 . Surge protection is promoted through the use of the at least one surge arrester  18 , also referred to as called metal oxide varistors (MOVs) or transient voltage surge suppressors (TVSS). The at least one surge arrester  18  provide surge, lightning, and brown-out protection to electrical devices that are connected to the same electrical circuit that the power factor correction device  2  is connected to. At least one knockout hole  7  for connecting the device to an electrical service is located on the enclosure  2 . 
         [0029]    With reference to  FIG. 4 , a perspective side view of a disconnect block  16  of the present invention is shown. The disconnect block  16  comprises an internal bridging bar  19  that allows a user to manually activate or deactivate the at least one capacitor  10  or individual discreet capacitive cells  22  of a variable capacitance capacitor  12  (shown further in  FIG. 5 ) depending on if a fixed-value capacitor is  13  or an individual discreet capacitive cell  12  is electrically connected to the disconnect block  16 . When the bridging bar  19  is in a closed position, as shown here, the bridging bar links two circuit bars  20  together, thereby creating an electrical circuit to a capacitor  10  and increasing the capacitance of the device  2 . To terminate the electrical circuit with a capacitor  10 , a user simply slides the bridging bar  19  into an open position, thereby breaking the link between the two circuit bars  20  and creating a space between the two circuit bars  20 . A locking means  21 , such as a screw, allows a user to lock the bridging bar in an open position or a closed position, thereby ensuring that the bridging bar will not accidentally slide from a closed position to an open position or vice versa. 
         [0030]    With reference to  FIG. 5 , a top view of a discreet capacitive cells  21  of a variable capacitance capacitor  12  is shown. The variable capacitance capacitor  12  is made up of multiple separate and discreet capacitive cells  22  each having individual taps  23  and a common terminal  24 . Each discreet capacitive cell  22  has a fixed capacitance level. The individual taps  23  allow a user to individually activate and deactivate each discreet capacitive cell  22  through the use of a disconnect blocks  16 , as shown in the  FIGS. 2-4 . For example a variable capacitance capacitor  12  with three multiple discreet capacitive cells  22 , one discreet capacitive cell  22  having a capacitance level of twenty microfarads, a second discreet capacitive cell  22  having a capacitance level of forty microfarads and a third discreet capacitive cell  22  having a capacitance level of forty microfarads, may be set using disconnect blocks  16  to capacitance levels of twenty microfarads, forty microfarads, sixty microfarads, eighty microfarads, or one-hundred microfarads. 
         [0031]    It is to be understood that while a preferred embodiment of the invention is illustrated, it is not to be limited to the specific form or arrangement of parts herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not be considered limited to what is shown and described in the specification and drawings.