Abstract:
A stand-alone circuit breaker assembly that includes a housing having a plurality of openings, a plurality of first bushings mounted through the openings in the housing for receiving electrical power from the distribution transformer, at least one circuit breaker, each circuit breaker having a plurality of input terminals and a plurality of output terminals, wherein the at least one circuit breaker is located inside the housing, a plurality of first electrical connectors electrically connected in one-to-one correspondence between the plurality of first bushings and the plurality of input terminals, a plurality of second bushings mounted through the openings in the housing for providing electrical power through the at least one circuit breaker, and a plurality of second electrical connectors electrically connected in one-to-one correspondence between the plurality of second bushings and the plurality of output terminals. The stand-alone circuit breaker can be utilized with a distribution transformer.

Description:
[0001]    This patent application is a continuation of patent application Ser. No. 12/189,917, which was filed on Aug. 12, 2008, which is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND OF INVENTION 
       [0002]    Conventional distribution transformers used in electric power distribution, e.g., on power lines, have an internal, built-in circuit breaker in a single assembly to protect the distribution transformer in some cases. To retrofit a distribution transformer by adding an internal circuit breaker is costly, and requires disruption of power to the customer for an unacceptable length of time. Moreover, the cost of unprotected distribution transformer is significantly less than a distribution transformer that has a built-in circuit breaker. 
         [0003]    Another problem occurs when a power surge hits a distribution transformer having an internal circuit breaker as a solitary unit; it may be so powerful that both the distribution transformer and circuit breaker are destroyed. This increases the time and cost of replacement. Also, in some cases, when one component goes bad, the entire combination unit of distribution transformer and circuit breaker must be replaced. 
         [0004]    A known distribution transformer system that utilizes a separate circuit breaker is disclosed in U.S. Pat. No. 3,183,362, which was assigned to System Analyzer Corp. and issued on May 11, 1965. However, this distribution transformer also included a series of switching contacts that are housed within the distribution transformer. When this distribution transformer fails or blows-up, complex repairs are required. It is not a simple matter of replacing a distribution transformer since there are contacts located within the distribution transformer that are actuated by the circuit breaker. Therefore, the circuit breaker as well as the distribution transformer are not stand-alone, replaceable units. Moreover, this is a one-of-a kind distribution transformer which makes it very difficult to maintain and replace. 
         [0005]    Therefore, a need exists in the art for a cost-effective solution that can be quickly installed to provide current overload protection for the distribution transformer with limited down-time to customers during installation. Also, a need exists for a low cost alternative to the expensive combination unit of distribution transformer and circuit breaker. 
         [0006]    The present invention is directed to overcome one or more of the problems as set forth above. 
       SUMMARY OF INVENTION 
       [0007]    An aspect of the present invention includes a stand-alone circuit breaker in a box assembly that can quickly be installed immediately in series with an existing transformer, thereby providing suitable overload protection to the transformer. In use, the circuit breaker box assembly is mounted near the distribution transformer and connected in series between the transformer and the end-user (load) so that electricity flowing between the transformer and the end-user must pass through the circuit breaker box assembly. The circuit breaker assembly is directly connected to the transformer. When a current overload is detected, the circuit breaker will sever the connection to the end-user, thus protecting the transformer. When the problem has been corrected, the circuit breaker can be reset, restoring power to the end-user. 
         [0008]    In one embodiment of the present invention, a single circuit breaker is provided that includes a circuit breaker mounted in a box, with the box having bushing assemblies installed thereto for wire connections. The circuit breaker may be implemented using a solenoid, a bimetallic strip, or both, as mere examples. The box is preferably sealable and at least partially filled with a non-conducting fluid such as mineral oil. The box may also include a fluid level sight gauge for viewing the level of the mineral oil or other fluid inside the box. The box may also include a fluid valve for conveniently filling or removing the fluid. Preferably, two sets of bushings are provided: one for the transformer side, and one for the load side. A circuit breaker is connected in series between the bushings so that current flowing between the transformer and the end-user must flow through the circuit breaker. When the circuit breaker allows electrical current to flow through, it is said to be in the closed position. When the circuit breaker does not allow current to flow through, it is said to be in the open or “tripped” position. In normal operation, the circuit breaker is in the closed position. If the current flowing through the circuit breaker is likely to cause the transformer to exceed acceptable parameters, the circuit breaker will trip and open the line, severing the electrical connection between the transformer and the load, thus preventing damage to the transformer. Once the circuit breaker has tripped, it activates an external trip signal such as a light, e.g., light-emitting diode (LED), mounted on the box. The trip signal serves to alert the technician to the fact that the circuit breaker inside the box has tripped, and must be reset to restore power to the end-user. The circuit breaker is externally resettable, i.e., it may be reset to a closed position without opening the box. The reset mechanism may be a mechanical handle that extends through an opening in the box that can be activated by using a hot-line stick. 
         [0009]    Optionally, the box may include multiple circuit breakers, so that multiple loads may be independently connected to the transformer via the circuit breaker box assembly. In this embodiment, a unique set of bushings would be provided for connecting each circuit breaker to each individual load. 
         [0010]    An aspect of the present invention includes a circuit breaker assembly. This circuit breaker assembly includes a housing having a plurality of openings, a plurality of first bushings mounted through the openings in the housing for receiving electrical power from a distribution transformer, a circuit breaker, having a plurality of input terminals and a plurality of output terminals, wherein the circuit breaker is located inside the housing, a plurality of first electrical connectors electrically connected in one-to-one correspondence between the plurality of first bushings and the plurality of input terminals, a plurality of second bushings mounted through the openings in the housing for providing electrical power from the circuit breaker, and a plurality of second electrical connectors electrically connected in one-to-one correspondence between the plurality of second bushings and the plurality of output terminals. 
         [0011]    Another aspect of the present invention includes a circuit breaker assembly. This circuit breaker assembly includes a housing having a plurality of openings, a plurality of first bushings mounted through the openings in the housing for receiving electrical power from a distribution transformer, a plurality of circuit breakers, each having a plurality of input terminals and a plurality of output terminals, wherein the plurality of circuit breakers are located inside the housing, a plurality of first electrical connectors electrically connected in one-to-one correspondence between the plurality of first bushings and the plurality of input terminals, a plurality of second bushings mounted through the openings in the housing for providing electrical power through the plurality of circuit breakers, and a plurality of second electrical connectors electrically connected in one-to-one correspondence between the plurality of second bushings and the plurality of output terminals. 
         [0012]    Still another aspect of the present invention includes an electrical power distribution system. This electrical power distribution system includes a distribution transformer, having a primary and a secondary, wherein the primary is capable of being electrically connected to a plurality of high voltage lines and the secondary includes a plurality of low voltage electrical conductors extending therefrom, a housing having a plurality of openings, a plurality of first bushings mounted through the openings in the container that are electrically connected to the plurality of low voltage electrical conductors, a plurality of circuit breakers, each having a plurality of input terminals and a plurality of output terminals, wherein the plurality of circuit breakers are located inside the housing, a plurality of first electrical connectors electrically connected in one-to-one correspondence between the plurality of first bushings and the plurality of input terminals, a plurality of second bushings mounted through the openings in the container for providing electrical power through the plurality of circuit breakers, and a plurality of second electrical connectors electrically connected in one-to-one correspondence between the plurality of second bushings and the plurality of output terminals. 
         [0013]    Yet another aspect of the present invention includes a method of protecting a distribution transformer. This method includes mounting an external, stand-alone circuit breaker assembly in proximity to a distribution transformer, electrically connecting the stand-alone circuit breaker assembly to the distribution transformer in series, and electrically connecting the stand-alone circuit breaker assembly to an end-user such that an electrical path is created flowing from the distribution transformer, through the circuit breaker assembly to the end-user, wherein the stand-alone circuit breaker assembly includes a housing having a plurality of openings, a plurality of first bushings mounted through the openings in the housing for receiving electrical power from the distribution transformer, at least one circuit breaker, each circuit breaker having a plurality of input terminals and a plurality of output terminals, wherein the at least one circuit breaker is located inside the housing, a plurality of first electrical connectors electrically connected in one-to-one correspondence between the plurality of first bushings and the plurality of input terminals, a plurality of second bushings mounted through the openings in the housing for providing electrical power through the at least one circuit breaker, and a plurality of second electrical connectors electrically connected in one-to-one correspondence between the plurality of second bushings and the plurality of output terminals. 
         [0014]    These are merely some of the innumerable aspects of the present invention and should not be deemed an all-inclusive listing of the innumerable aspects associated with the present invention. These and other aspects will become apparent to those skilled in the art in light of the following disclosure and accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0015]    For a better understanding of the present invention, reference may be made to the accompanying drawings in which: 
           [0016]      FIG. 1  illustrates a top-down view of an exemplary embodiment of the present invention utilizing a single circuit breaker shown with the lid removed; 
           [0017]      FIG. 2  illustrates a side view of an exemplary embodiment of the present invention utilizing a single circuit breaker, as shown in  FIG. 1 ; 
           [0018]      FIG. 3  illustrates a second side view of an exemplary embodiment of the present invention utilizing a single circuit breaker, as shown in  FIG. 1 ; 
           [0019]      FIG. 4  illustrates a third side view of an exemplary embodiment of the present invention utilizing a single circuit breaker, as shown in  FIG. 1 ; 
           [0020]      FIG. 5  illustrates a top-down view of an alternative embodiment of the present invention utilizing a double circuit breaker shown with the lid removed; 
           [0021]      FIG. 6  illustrates a side view of an alternative embodiment of the present invention utilizing a double circuit breaker, as shown in  FIG. 5 ; 
           [0022]      FIG. 7  illustrates a second side view of an alternative embodiment of the present invention utilizing a double circuit breaker, as shown in  FIG. 5 ; and 
           [0023]      FIG. 8  illustrates a third side view of an alternative embodiment of the present invention utilizing a double circuit breaker, as shown in  FIG. 5 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0024]    In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. Additionally, the present invention contemplates that one or more of the various features of the present invention may be utilized alone or in combination with one or more of the other features of the present invention. 
         [0025]      FIGS. 1-4  illustrate an exemplary embodiment of the present invention wherein the assembly contains a single circuit-breaker that is generally indicated by numeral  1 .  FIG. 1  shows a tank case  10  containing a circuit breaker  13 . The tank case  10  can be any solid material, e.g., steel or hard plastic. The circuit breaker  13  includes a breaker handle  14  which extends through an opening in the tank case  10 , allowing the circuit breaker  13  to be reset without opening the tank case  10  with a hot-line stick. There is an internally threaded handle nut  15  located inside the tank case  10  that receives an externally threaded cylindrical portion  16  of the breaker handle  14 . A tank gasket  19  is fixedly attached to the tank case  10  and can include any material capable of forming a tight seal, e.g., rubber. There is a wide variety of circuit breakers that can be utilized with the present invention. Any of a wide variety of automatically-operated electrical switches designed to protect an electrical circuit from damage caused by overload or short circuit will suffice. There are magnetic circuit breakers that utilize a solenoid whose pulling force increases exponentially as the current increases. The circuit breaker&#39;s contacts are held closed by a latch and, as the current in the solenoid increases beyond the rating of the circuit breaker, the solenoid&#39;s pull releases the latch which then allows the contacts to open by spring action. There are thermal breakers that utilize a bimetallic strip, which heats and bends with increased current, and is similarly arranged to release the latch. There are also thermomagnetic circuit breakers that utilize both of the above techniques. The circuit breakers typically utilized for larger currents are usually arranged with pilot devices to sense a fault current and to operate the trip opening mechanism. 
         [0026]    The tank case  10  is preferably filled with a non-conducting tank fluid, e.g., mineral oil. However, the tank case  10  does not absolutely need a non-conducting tank fluid and can simply be filled with air or vacuum. The tank fluid serves as a heat sink to prevent overheating of the device, and also provides arc-suppression to prevent arcing inside the tank. The tank fluid may also provide anti-corrosive benefits. 
         [0027]    The tank case  10  includes a fluid valve  12  for filling or draining of the tank fluid from the tank case  10 . The tank case  10  further includes a fluid level sight gauge  17  which allows the operator to view the fluid level in the tank case  10 . The tank case  10  further includes a pressure release valve (PRV)  18  to expel non-conducting tank fluid from the tank case  10  in the event that the fluid pressure in the tank case  10  becomes too high. 
         [0028]    Referring now to  FIGS. 2 ,  3  and  4 , the tank case  10  further includes a ground lug  20 , which can be any solid electrically conducting material. In use, the ground lug  20  is electrically connected to some type of ground wire connection (not shown). 
         [0029]    Referring again to  FIG. 1 , there is a first high voltage line  32 , a second high voltage line  34  and a third high voltage line  36 , which are electrically connected to the primary of a standard, unprotected distribution transformer  30 . From the secondary of the standard, unprotected distribution transformer  30  there is a first electrical, low voltage, output line  40 , a second electrical, low voltage, output line  42  and a third electrical, low voltage, output line  44 . The first electrical, low voltage, output line  40  is electrically connected to a first input bushing  46 , the second electrical, low voltage, output line  42  is electrically connected to a second input bushing  48  and the third electrical, low voltage, output line  44  is electrically connected to a third input bushing  50 . Although bushings are disclosed as the preferred embodiment, any of a wide variety of electrical connecting mechanisms will suffice. 
         [0030]    There is a first electrical conductor  52  that is electrically connected to a first terminal  54  of the circuit breaker  13 , a second electrical conductor  56  that is electrically connected to a second terminal  58  of the circuit breaker  13  and a third electrical conductor  60  that is electrically connected to a third terminal  62  of the circuit breaker  13 . 
         [0031]    On the output side of the circuit breaker  13 , there is a fourth electrical conductor  72  that is electrically connected to a fourth terminal  70  of the circuit breaker  13 , a fifth electrical conductor  74  that is electrically connected to a fifth terminal  76  of the circuit breaker  13  and a sixth electrical conductor  78  that is electrically connected to a sixth terminal  80  of the circuit breaker  13 . 
         [0032]    The fourth electrical conductor  72  is electrically connected to a first output bushing  82 , the fifth electrical conductor  74  is electrically connected to a second output bushing  84  and the sixth electrical conductor  78  is electrically connected to a third output bushing  86 . Electrically connected thereto and extending from the first output bushing  82 , the second output bushing  84  and the third output bushing  86  are a first output line  88 , a second output line  90  and third output line  92 , respectively. 
         [0033]    Referring again to  FIGS. 2 ,  3  and  4 , the tank case  10  further includes a lightning arrestor or surge protector  22 , which is also shown in  FIG. 1 . The lightning arrestor  22  is electrically connected between at least two of the first output bushing  82  via a seventh conductor  73 , the second output bushing  84  via an eighth conductor  75  and the third output bushing  86  via a ninth conductor  77 . The lightning arrestor  22  is also electrically connected to ground lug  20  via a ground conductor  21 . The lightning arrestor  22  protects equipment by diverting to ground any voltage surge above a predetermined value picked up from close lightning hits. For the lightning arrestor  22 , there is no conductivity below the predetermined voltage and above the predetermined voltage; there is silicon oxide resistance in the lightning arrestor, which breaks down diverting current to ground within nanoseconds. Although the preferred wiring occurs outside of the tank case  10 , it is possible to locate the seventh conductor  73 , the eighth conductor  75 , the ninth conductor  77  and the ground conductor  21  within the tank case  10 . 
         [0034]    Referring again to  FIG. 1 , a heater  11  can be optionally utilized in conjunction with a temperature controller  71 , e.g., thermostat, to maintain oil temperature so the response time of the breaker is not influenced by fluctuations in ambient temperature. The temperature controller  71 , e.g., thermostat, can be powered by a first temperature controller power conduit  27  that is electrically connected to the fourth terminal  70  of the circuit breaker  13 , a second temperature controller power conduit  28  that is electrically connected to the fifth terminal  76  of the circuit breaker  13 ; and a third temperature controller power conduit  29  that is electrically connected to sixth terminal  80  of the circuit breaker  13 . 
         [0035]    An illustrative, but nonlimiting, example of an oil-filled transformer having a heater and thermostat for regulating temperature is found in U.S. Pat. No. 4,192,174, issued on Mar. 11, 1980 to Lobermann et al., which is incorporated herein by reference in its entirety. 
         [0036]    As shown in  FIG. 1 , attached to the side of the tank case  10  is a signal light  24  that is secured by signal light nut  25 . The signal light nut  25  is internally threaded to receive the externally threaded cylindrical end of the signal light  24 . There is a first terminal  95  and a second terminal  96  that are electrically connected to the circuit breaker  13  that operate as a switch when the circuit breaker  13  is within a predetermined value of current over time. This electrical signal occurs when an overload situation is imminent. The signal light  24  is connected to the first terminal  95  through a first signal connector  98  while the second terminal  96  is connected to the first terminal  54  of the circuit breaker  13  via a second signal connector  97 . There is a third signal connector  99  that is connected between the signal light  24  and the second terminal  58  of the circuit breaker  13 . A small transformer (not shown) may be utilized to decrease the voltage between the signal light  24  and the first terminal  95 . Preferably, a circuit breaker  13 , e.g., bimetal circuit-breaker, is utilized that can provide a signal to the signal light  24  in an overload situation prior to the circuit breaker  13  being tripped. Once the circuit breaker  13  is tripped, a breaker handle  14  which extends through an opening in the tank case  10  allows the circuit breaker  13  to be reset without opening the tank case  10 . 
         [0037]      FIGS. 2 ,  3  and  4  illustrate the tank case  10  with a tank lid  23  attached. The tank lid  23  can be any solid material, e.g., steel or hard plastic. The tank gasket  19  fits between tank case  10  and the tank lid  23  providing a tight seal. 
         [0038]    A first alternative embodiment of a dual circuit breaker system, as shown in  FIGS. 5-8 , is generally indicated by numeral  100 .  FIG. 5  shows a tank case  110  containing a first circuit breaker  113 . The tank case  110  can be any solid material, e.g. steel or hard plastic. There is a first circuit breaker  113  that includes a first breaker handle  114  which extends through an opening in the tank case  110 , allowing the first circuit breaker  113  to be reset without opening the tank case  110 . Also, there is a second circuit breaker  104  that includes a second breaker handle  105  which also extends through an opening in the tank case  110 , allowing the second circuit breaker  104  to be reset without opening the tank case  110 . There is a first internally threaded handle nut  115  located inside the tank case  110  that receives a first externally threaded cylindrical portion  116  of the first breaker handle  114  and a second internally threaded handle nut  106  located inside the tank case  110  that receives a second externally threaded cylindrical portion  107  of the second breaker handle  105 . A tank gasket  119  is fixedly attached to the tank case  110  and can include any material capable of forming a tight seal, e.g., rubber. 
         [0039]    The tank case  110  is preferably filled with a non-conducting tank fluid, e.g., mineral oil. However, the tank case  110  does not absolutely need a non-conducting tank fluid and can simply be filled with air or vacuum. The tank fluid serves as a heat sink to prevent overheating of the device, and also provides arc-suppression to prevent arcing inside the tank case  110 . The tank fluid may also provide anti-corrosive benefits. 
         [0040]    As shown in  FIGS. 5 and 6 , the tank case  110  includes a fluid valve  112  for filling or draining of the tank fluid from the tank case  110 . The tank case  110  further includes a fluid level sight gauge  117  which allows the operator to view the fluid level in the tank case  110 . As shown in  FIGS. 5 and 8 , the tank case  110  further includes a pressure release valve (PRV)  118  to expel non-conducting tank fluid from the tank case  110  in the event that the fluid pressure in the tank case  110  becomes too high. 
         [0041]    Referring now to  FIGS. 6 and 8 , the tank case  110  further includes a first ground lug  120 , which can be any solid electrically conducting material. In use, the first ground lug  120  is electrically connected to some type of ground wire connection (not shown). Also, the tank case  110  further includes a second ground lug  220 , also shown in  FIG. 7 , which can be any solid electrically conducting material. In use, the first ground lug  220  is electrically connected to some type of ground wire connection (not shown). 
         [0042]    Referring again to  FIG. 5 , there is a first high voltage line  132 , a second high voltage line  134  and a third high voltage line  136 , which are electrically connected to the primary of a standard, unprotected distribution transformer  130 . From the secondary of the standard, unprotected distribution transformer  130  there is a first electrical line  140  that is electrically connected to a first input bushing  182 , a second electrical line  142  that is electrically connected to a second input bushing  184 , and a third electrical line  144  that is electrically connected to a third input bushing  186 . 
         [0043]    On the input side of a first circuit breaker  113 , there is a first electrical conductor  173  that is electrically connected to a first terminal  166  of the first circuit breaker  113 , a second electrical conductor  174  that is electrically connected to a second terminal  167  of the first circuit breaker  113  and a third electrical conductor  175  that is electrically connected to a third terminal  168  of the first circuit breaker  113 . 
         [0044]    On the input side of a second circuit breaker  104 , there is a fourth electrical conductor  176  that is electrically connected to a fourth terminal  169  of the second circuit breaker  104 , a fifth electrical conductor  177  that is electrically connected to a fifth terminal  170  of the second circuit breaker  104  and a sixth electrical conductor  178  that is electrically connected to a sixth terminal  171  of the second circuit breaker  104 . 
         [0045]    On the output side of the first circuit breaker  113 , there is a seventh electrical conductor  156  that is electrically connected to a fourth terminal  161  of the first circuit breaker  113 , an eighth electrical conductor  154  that is electrically connected to a fifth terminal  160  of the first circuit breaker  113  and a ninth electrical conductor  152  that is electrically connected to a sixth terminal  159  of the first circuit breaker  113 . The seventh electrical conductor  156  is electrically connected to a first output bushing  150 , the eighth electrical conductor  154  is electrically connected to a second output bushing  148 , and the ninth electrical conductor  152  is electrically connected to a third output bushing  146 . 
         [0046]    On the output side of the second circuit breaker  104 , there is a tenth electrical conductor  157  that is electrically connected to a fourth terminal  164  of the second circuit breaker  104 , an eleventh electrical conductor  155  that is electrically connected to a fifth terminal  163  of the second circuit breaker  104  and a twelfth electrical conductor  153  that is electrically connected to a sixth terminal  162  of the second circuit breaker  104 . The tenth electrical conductor  157  is electrically connected to a fourth output bushing  151 , the eleventh electrical conductor  155  is electrically connected to a fifth output bushing  149 , and the twelfth electrical conductor  153  is electrically connected to a sixth output bushing  147 . 
         [0047]    As shown in  FIGS. 6 and 8 , the tank case  110  further includes a first lightning arrestor or surge protector  122 . The first lightning arrestor  122  is also electrically connected to a first ground lug  120  via a first ground conductor  121 . The first lightning arrestor  122  protects equipment by diverting to ground any voltage surge above a predetermined value picked up from close lightning hits. For the first lightning arrestor  122 , there is no conductivity below the predetermined voltage and above the predetermined voltage; there is silicon oxide resistance in the lightning arrestor, which breaks down diverting current to ground within nanoseconds. The first lightning arrestor  122  is electrically connected to the first output bushing  150  via a thirteenth electrical conductor  202 , the second output bushing  148  via a fourteenth electrical conductor  204 , and the third output bushing  146  via a fifteenth electrical conductor  206 . Although the preferred wiring occurs outside of the tank case  110 , it is possible to locate the thirteenth electrical conductor  202 , the fourteenth electrical conductor  204 , the fifteenth electrical conductor  206 , and the first ground conductor  121  within the tank case  110 . 
         [0048]    As shown in  FIGS. 5-8 , the tank case  110  further includes a second lightning arrestor or surge protector  222 . The second arrestor  222  is also electrically connected to a second ground lug  220  via a second ground conductor  221 . The second lightning arrestor  222  protects equipment by diverting to ground any voltage surge above a predetermined value picked up from close lightning hits. For the second lightning arrestor  222 , there is no conductivity below the predetermined voltage and above the predetermined voltage; there is silicon oxide resistance in the lightning arrestor, which breaks down diverting current to ground within nanoseconds. The second lightning arrestor  222  is electrically connected to the fourth output bushing  151  via an sixteenth electrical conductor  212 , the fifth output bushing  149  via a seventeenth electrical conductor  210 , and the sixth output bushing  147  via a eighteenth electrical conductor  208 . Although the preferred wiring occurs outside of the tank case  110 , it is possible to locate the sixteenth electrical conductor  212 , the seventeenth electrical conductor  210 , and the eighteenth electrical conductor  208 . and the second ground conductor  221  within the tank case  110 . 
         [0049]    Referring again to  FIG. 5 , a heater  111  can be optionally utilized in conjunction with a temperature controller  271 , e.g., thermostat, can be used to maintain oil temperature so the response time of the breaker is not influenced by fluctuations in ambient temperature. The temperature controller  271 , e.g., thermostat, can be powered by a first temperature controller power conduit  227  that is electrically connected to the first output bushing  182 ; a second temperature controller power conduit  228  that is electrically connected to the second output bushing  184 ; and a third temperature controller power conduit  229  that is electrically connected to the third output bushing  186 . 
         [0050]    Optionally, a heater  111 , utilized in conjunction with a temperature controller  271 , e.g., thermostat, can be used to maintain oil temperature so the response time of the breaker is not influenced by fluctuations in ambient temperature. An illustrative, but nonlimiting, example of an oil-filled transformer having a heater and thermostat for regulating temperature is found in U.S. Pat. No. 4,192,174, issued on Mar. 11, 1980 to Lobermann et al., which is incorporated herein by reference in its entirety. 
         [0051]    As shown in  FIG. 5 , attached to the side of the tank case  110  is a first signal light  207  that is secured by first signal light nut  209 . The first signal light nut  209  is internally threaded to receive the externally threaded cylindrical end of the first signal light  207  that is electrically connected via a first signal conductor  232  to the first terminal  228  of the first circuit breaker  113 . There is a second terminal  226  of the first circuit breaker  113  that is electrically connected to the third terminal  168  of the first circuit breaker  113  via a second signal conductor  231 . The first signal light  207  is also connected to the second terminal  167  of the first circuit breaker  113  via a third signal conductor  230 . The first terminal  228  and the second terminal  226  are electrically connected to the first circuit breaker  113  and operate as a switch when the first circuit breaker  113  is within a predetermined value of current over time. This electrical signal occurs when an overload situation is imminent. 
         [0052]    Also shown in  FIG. 5 , attached to the side of the tank case  110  is a second signal light  211  that is secured by second signal light nut  213 . The second signal light nut  211  is internally threaded to receive the externally threaded cylindrical end of the second signal light  211  that is electrically connected via a fourth signal conductor  240  to the first terminal  236  of the second circuit breaker  104 . There is a second terminal  234  of the second circuit breaker  104  that is electrically connected to the sixth terminal  171  of the second circuit breaker  104  via a fifth signal conductor  239 . The second signal light  211  is also connected to the fifth terminal  170  of the second circuit breaker  104  via a sixth signal conductor  238 . The first terminal  236  and the second terminal  234  are electrically connected to the second circuit breaker  104  and operate as a switch when the second circuit breaker  104  is within a predetermined value of current over time. This electrical signal occurs when an overload situation is imminent. 
         [0053]      FIGS. 6 ,  7  and  8  illustrate the tank case  110  with a tank lid  123  attached. The tank lid  123  can be any solid material, e.g., steel or hard plastic. The tank gasket  119  fits between tank case  110  and the tank lid  123  providing a tight seal. 
         [0054]    Thus, there has been shown and described several embodiments of a novel invention. As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. The terms “have,” “having,” “includes,” and “including” and similar terms as used in the foregoing specification are used in the sense of “optional” or “may include” and not as “required.” Many changes, modifications, variations and other uses and applications of the present construction will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims that follow.