Abstract:
A load bank that is used to test electrical connections. The connections are attached to the load bank, so that the switches are loaded during the testing. The overheating or underheating, of either switches or loads can be tested, evaluated, and used to determine faults and errors.

Description:
This application claims priority from provisional application No. 60/864,133, filed Nov. 2, 2007, the disclosure of which is herewith incorporated by reference. 
    
    
     BACKGROUND 
     In a commercial stage environment, power must be distributed to loads. The power distribution usually occurs using a power distribution box which may include commercial electronic devices such as circuit breakers, dimmers, and other analogous parts. 
     In large venues, when it is necessary to produce many different power outputs to many different devices, reliability of that power distribution device may become an issue. The reliability issue is even more important in rental parts, where items are rented and returned, then rented to others. 
     SUMMARY 
     The present application describes a load bank and connection system which allows evaluation and testing of power distribution parts. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     The general structure and techniques, and more specific embodiments which can be used to effect different ways of carrying out the more general goals, are described herein. 
       FIG. 1  shows an embodiment. A commercial source of power  100 , for example, a generator or a connection to a high current power source, is connected via a cable  105  to an electronic control box  110 . The electronic control box  110  may include a number of electronic devices including breakers such as  111 , and dimmers such as  112 . The device may also include other electrical control devices. The main function of the control box  110  is intended to be distribution of power to remote loads. In operation, the output cable  120  includes a plurality of seperate output cables that are intended for distribution to a number of different locations. Each output cable may have a specified connector such as  121 . A number of different standard format connectors are known, including single circuit type connectors, such as “stage pin” connectors, twist lock connectors, “Edison” connectors, 14           50 connectors, or multi-connectors, such as Socapex connectors, or others.
     A distribution box  130  is located to receive the connectors for testing in this embodiment. The distribution box  130  includes a connector panel  131  which may include a number of different connectors, such as  132 , of various types. The connectors may be standard connectors, for example, they may include locations for one hundred different connectors. The distribution box  130  also includes an output portion  135 . Each of the input connectors can be connected via a splice connector such as  136  to an output connector  137  or  138 . Each of those connectors  137 ,  138  may have one connection pin, or may have multiple such connection pins. The distribution box  130  may also indicator lights, e.g., load status lights that are connected in series with the load or to otherwise detect the load, and which may have individual lights such as  153 ,  154 , that light when loads are connected. The box  130  may also have status indicator lights to show other features. 
     Each output connector is connected to a specified resistance within a load box. In the embodiment, there are two different load boxes shown as  140  and  150 . The load box  140  includes a plurality of resistors such as  141 . Each resistor such as  141  is connected individually to a different power output. For example, connection to the connector  137  may connect a plurality of different power sources to the different resistors such as  141 ,  142 , that each one power source output is connected to an individual resistor. The resistors, for example, may be sized with comparable size resistances to form a proper amount of power load, and hence stress, on the breakers or dimmers (e.g. 75% of maximum rated load). For example, the resistors may dissipate 3000 W per resistor for a 30 amp circuit 
     In another embodiment, the resistors may be configurable, so that for example, a connection such as  143  between resistors  141  and  142  can be made to allow two resistors to be connected in series, or two resistors to be connected in parallel. 
     A separate load box  150  may be configured separately for different voltages, such as 208 volts, or for multiple phase output power. 
     In the embodiment, the load box may be vented on top and sides. It may be fan cooled or convection cooled. It may be sized to be placed on a roof, or the like. 
     A top-mounted rain shield  156  is spaced from the top of the load box, and allows the box to dissipate power, but prevents rain from reaching the loads such as  141 , which may otherwise be damaged by cool liquid. 
     The testing of the electrical loads looks for different circuits which are either failing, or not working quite as well. For example, breakers sometimes soften over time, and become resistive. By testing under load, a determination can be made of whether the breaker will withstand the proper electrical loading. If the breaker is defective, it is likely to fail during the test. If the breaker is becoming resistive, it will heat up during the test. 
     Another aspect uses an infrared camera and/or some other kind of sensor  160 , which can be either manually observed, or can be monitored by a computer  170 . The infrared camera  160  may view either the power distribution box  110 , or at either of the loading boxes. When viewing the power distribution box  110 , the infrared camera  160  can look for hotspots, for example. In one embodiment, the breaker box can be operated under load, and a snapshot of the breaker box under load can be taken by the infrared camera. Either the computer  170 , or an operator can later look at the breaker box to determine whether any of the breakers are overheating. For example, the computer may automatically look for indications of hot areas within the image. If one breaker is hotter than the others, this can indicate an already-occurring failure, or an imminent failure. Other sensors may include pyrometers, and laser based temperature sensors, which can alternatively be used for this function. As an alternative, the sensing can sense current within the resistor(s)  141 , e.g., using an ammeter attached to the loads, or using a remote current sensing such as Hall effect. 
     An infrared camera or sensor  160  is one example of a fault detection system that automatically detects a fault by term in detecting a heat amount thereof. For example, the dimmer may be flagged as faulty when it overheats, and in essence gets too hot. The load bank may also signal a fault, however, when it underheats, meaning that not enough power or no power at all is being delivered to one of the specified loads By detecting which loads are getting hot, the system can automatically make a determination of the errors in the connection panel  110 . 
     The general structure and techniques, and more specific embodiments which can be used to effect different ways of carrying out the more general goals are described herein. [0014] Although only a few embodiments have been disclosed in detail above, other embodiments are possible and the inventors intend these to be encompassed within this specification. The specification describes specific examples to accomplish a more general goal that may be accomplished in another way. This disclosure is intended to be exemplary, and the claims are intended to cover any modification or alternative which might be predictable to a person having ordinary skill in the art. For example, other resistance sizes can be used, and other devices can be tested in this way. 
     Also, the inventors intend that only those claims which use the words “means for” are intended to be interpreted under 35 USC 112, sixth paragraph. Moreover, no limitations from the specification are intended to be read into any claims, unless those limitations are expressly included in the claims. The computers described herein may be any kind of computer, either general purpose, or some specific purpose computer such as a workstation. The computer may be a Pentium class computer, running Windows XP or Linux, or may be a Macintosh computer. The computer may also be a handheld computer, such as a PDA, cellphone, or laptop. 
     The programs may be written in C, or Java, Brew or any other programming language. The programs may be resident on a storage medium, e.g., magnetic or optical, e.g. the computer hard drive, a removable disk or media such as a memory stick or 3D media, or other removable medium. The programs may also be run over a network, for example, with a server or other machine sending signals to the local machine, which allows the local machine to carry out the operations described herein.