Lighting arrangement with a control box including controller and power supplies

A lighting arrangement includes a control box which defines a line voltage wiring channel and a low voltage area and has at least one low voltage power supply mounted in the line voltage wiring channel and a controller mounted in the low voltage area and communicating with the low voltage power supply.

BACKGROUND

In a typical prior art lighting arrangement for a classroom or a commercial building, there are several separate light fixtures, each with its own fluorescent ballast or LED power supply. The installation of these lighting arrangements is expensive in terms of labor and materials, as it requires running conduit with line voltage (110V or greater) to each light fixture.

In the prior art, the lighting components are located on hard-wired junction boxes in multiple locations above the dropped ceilings. Running conduit, mounting electrical boxes, installing flexible conduits, and making wiring connections are the major part of installing the lighting system. Ductwork for heating and air conditioning, and plumbing pipes and sprinkler systems are then mounted above the dropped ceilings. The dropped ceilings, ductwork, and pipes then obscure and make it difficult to find the devices and get access to them to maintain or replace components, making maintenance and repair difficult and time consuming. Installation and field wiring also are time consuming and expensive.

SUMMARY

The present invention provides a lighting arrangement that is much less expensive to install and to maintain, because the low voltage power supplies for several light fixtures are located in a single electrical box, and low voltage cables are run from the low voltage power supplies to the various light fixtures. A controller is located in a low voltage area of the box, which is separate and isolated from the line voltage area in which the power supplies are located, and the controller controls the power supplies. The controller may communicate with various sensors and controllers through low voltage cables. The electrical box may be designed to fit within the confines of a 2′×2′ suspension grid typical of dropped ceiling tiles (such as acoustic ceiling tiles). The electrical box may be sized to replace one of the 2′×2′ ceiling tiles and may include a hinged and cam-latched door to access the interior of the electrical box. When the hinged door is swung open, it reveals the interior of the electrical box, which is physically segregated into a line voltage wiring conduit (110V or greater) and a low voltage area (58 V or less), with access to the factory wired line voltage conduit being isolated by a channel cover to make it safe for a non-electrician (such as a maintenance man or handyman) to handle low voltage interconnections as well as common troubleshooting and maintenance tasks.

A photo sensor may be mounted on the outside of the hinged door and may communicate with the controller in the low voltage area in order to maintain the desired environmental light level regardless of the external light conditions (such as sunny, overcast, or nighttime). In addition to or instead of the photo sensor, a motion sensor may allow the controller to automatically turn off any lights as long as no motion has been detected in the room, and turn them back on when motion is detected. By mounting the photo- and/or motion-detect sensor, controller and power supplies all in the same box, with the low voltage control area segregated from the line voltage wiring channel, and by using modular, plug-in type connections, the installation and troubleshooting are much easier than in prior art installations. For example, an installation that normally would take two months can be performed in two days, and most of the installation can be performed by people who are not licensed electricians.

DESCRIPTION

FIGS. 1-4are schematic views of a lighting system10made in accordance with the present invention. The lighting system10includes a plurality of control boxes12, with each control box12mounted in a room and connected to a plurality of remotely mounted light fixtures14in that room. In this particular embodiment, the light fixtures14are low voltage, LED light fixtures without power supplies. Instead of having a power supply located at each light fixture14, the power supplies16for the light fixtures14in a room are mounted within the control box12for that room, as shown inFIGS. 2-4.

Referring back toFIG. 1, the building11may be a commercial office building, a school, or even a hospital, for instance. The building has a plurality of rooms13(labeled Room101,102,103, etc.), and each room has a control box12. A computer17may be hooked up to a master controller15in order to program the master controller15to communicate with the control boxes12to control the lighting system10. The master controller15is daisy-chain connected to the control boxes12through low voltage cables18. The light fixtures14are also connected to their respective control box12through low voltage cables18.

Each control box12is a PTP rated (Point-to-Point) electrical box enclosure which, in this embodiment, is 2′ wide×2′ long×4.75″ tall so as to fit within one 2′×2′ square in the suspension grid of a dropped ceiling. The control box12transmits less than 10.5 milliamps of leakage current when high-potential tested with 600 volts for 60 seconds of operation. The control box12has side walls36A, a top wall36, and a hinged door40, which forms a bottom wall. The top four corners of the control box12include upwardly projecting, external tabs21defining openings which permit the control box12to be suspended by cables23from the structure above the dropped ceiling. The control box12is designed to replace one of the tiles in the dropped ceiling.

Inside the control box12and extending along its entire periphery is a line voltage wiring channel19(SeeFIG. 3). This channel19is formed and defined by four substantially “L” shaped channel covers22(only one of which is shown inFIG. 2), cooperating with the top36and side walls36A, as best appreciated inFIGS. 2-4. Line voltage (110V or greater) exists in the control box12only within the confines of this line voltage wiring channel19. Fewer or more covers22may be used to define the line voltage wiring channel19, as desired. In this embodiment, the covers22are mounted to the top36of the box12by fasteners42.

The low voltage power supplies16are mounted inside the line voltage wiring channel19in the factory. Each line voltage wiring channel19is capable of supplying power to twelve LED lighting fixtures. Also in the factory, these low voltage power supplies16are connected to an electrical bus28via quick-connect stab-in connectors. The bus28will receive line voltage when the box12is installed in the field. The low voltage power supplies16have low voltage output plug-in connectors, designed to receive a plug from a low voltage cable.

In order to provide an external connection to each low voltage output on the low voltage power supplies, a plurality of short, low voltage cables18A with connectors at both ends, are installed at the factory. Each of the short cables18A is plugged into a low voltage output of a low voltage power supply16and projects out of the line voltage wiring channel19of the control box12through one of the openings24in the top wall36of the control box12located above the low voltage power supplies16. The control box12is manufactured with these short connectors18A projecting out of the box, so an installer can make all the connections from the low voltage light fixtures14to the control box12without having to access the line voltage channel19.

A plurality of longer, low voltage cables18with plugs at both ends are used to connect from each low voltage, LED light fixture14to one of the short cables18A, plugging into a female receptacle26in the light fixture14at one end and into one of the short cables18A at the other end, in order to connect each LED light fixture to the low voltage output of one of the low voltage power supplies16housed within the line voltage wiring channel19.

In the field, an electrician removes the cover22covering the pre-wired bus28, brings a single line voltage cable20(SeeFIG. 2) to the inside of the line voltage wiring channel19, and connects the line side power to the electrical bus28inside the channel19via a three-wire, insulated 600 volt conductor (positive, neutral, and ground). The electrician then reinstalls the channel cover22over the area of the bus28, to finish enclosing the entire line voltage channel19, leaving a low voltage area34in the central area of the control box12, with the outer perimeter of the low voltage area34isolated from the line voltage wiring channel19by the channel covers22.

A controller30, which in this embodiment is a low voltage control dimming switching transformer relay (SeeFIGS. 2 and 3), is mounted in the factory on the low voltage side of the channel cover22which covers the bus28.

The controller30has a small appendage32that projects through an opening in the channel cover22and into the line voltage wiring channel19, where it is connected to the bus28for receiving line voltage power and for communicating with the low voltage power supplies16. The controller30has a plurality of female plug-in connections located in the low voltage area34of the control box12, which receive male CAT6connectors on the CAT6low voltage cabling18.

To summarize, all line voltage components and line voltage electrical connections reside within the confines of the line voltage wiring channel19found along the periphery of the control box12. The line voltage wiring channel19is defined by the side walls36A and top wall or ceiling36of the control box12and by the “L” shaped channel covers22. The covers22isolate the low voltage area34in the central area of the control box12from the line voltage wiring channel19. The low voltage controller30resides within the confines of the low voltage area34(SeeFIG. 3).

Since the connections from the low voltage power supplies16to their respective low voltage, LED light fixtures14are low voltage cables18,18A (SeeFIG. 2), there is no need to install conduit to each light fixture14. Instead, a simple low voltage power cable18,18A (such as a CAT6cable) extends from the low voltage side of each power supply16to its respective light fixture14, and the installer can make the plug-in connections on the cable18without entering the line voltage wiring channel19. This substantially reduces the cost of installing the lighting arrangement by reducing the cost of materials and labor.

The low voltage power supply16will supply, and the low voltage power cable18,18A will carry, a low voltage current, from 12 volts to 58 volts, to the low voltage light fixture14, depending upon the requirements of the light fixture14.

As shown inFIGS. 3 and 4, the top wall36of the control box12has several openings38for allowing access of low voltage lines into the low voltage area34of the control box12. So, for example, the daisy chain control lines18shown inFIG. 1, which extend from the central controller15, to one control box12, and then from that control box12to another control box12enter the low voltage area34of their respective control box through one of the openings38. Other low voltage lines, such as a low voltage line carrying a low voltage signal from a remote motion sensor or a remote, wall-mounted light switch25or remote light sensor, may enter the low voltage area34through one of the openings38, and then plug into one of the low voltage receptacles in the controller30.

FIG. 2shows that the control box12has a hinged door40which forms the bottom wall of the control box12. The door40has hinges40A on one side edge and cam latches40B on the opposite side edge, which are received by the side walls of the control box12to allow the door40to swing open and closed and to be secured in the closed position. The door40may be swung open from below by an installer or repair person to give access to the controller30and to the power supplies16for all the light fixtures14in the room13. It also gives access to any other controls that may be mounted in the box12. This facilitates installation, troubleshooting, and repair of the lighting system. It should be noted that the channel covers22impede access to the power supplies16(and indeed impede access to the line voltage side of the box12) until and unless the channel covers22are first removed (the channel covers22may be removed by removing the fasteners42securing the channel covers22to the box12).

FIG. 2shows that the door40has a knock-out opening, which is used to mount a motion detector and/or photo sensor44on the room side of the door40. The motion detector/photo sensor44has a receptacle which receives a plug end of a low voltage cable18, the other end of which plugs into the controller30. This low voltage cable18is long enough to permit the door40to swing open while both ends of the cable18are plugged in. The motion detector/photo sensor44tells the controller30when a person is in the room by detecting motion in the room and tells the controller30the level of light in the room so the control system can control the level of light provided by the light fixtures14depending upon whether the room is occupied and depending upon the level of natural light in the room.

The control box12and light fixtures14are intended to be installed in the ceiling of a classroom or commercial building. They may be recessed in a lay-in, drop ceiling, flush mounted on a drywall ceiling, or mounted in other known ways. The control box12could be mounted in the wall or elsewhere instead of the ceiling, if other locations are more convenient, but it is contemplated that the ceiling will be the most convenient location in most cases.

It will be obvious to those skilled in the art that modifications may be made to the embodiment described above without departing from the scope of the invention as claimed. For instance, other types of low voltage cabling may be used and various types of sensors and control arrangements may be used. While this embodiment shows the use of low voltage LED lights, other types of low voltage lights could be used. The control box may be mounted in various orientations, so that the bottom becomes the front, and so forth.