Electric panel heat alarm with a thermally non-conductive mounting arrangement

#The present invention relates to a heat alarm for an electric panel cabinet. More specifically, the present invention relates to a heat alarm that includes a thermally non-conductive mounting arrangement that thermally isolates the heat alarm from the electric panel cabinet.

#Electric panel cabinets typically house the main electric service panels or subpanels for the electric supply to a residential or commercial building. Electric panel cabinets typically contain many components that may overheat and start fires, such as feeder conductors, branch circuit conductors, circuit breakers, fuses, and bus bars. The overheating of one of these electrical components within an electric panel cabinet can be caused by many types of malfunctions, such as loose or corroded connections, power overloads, or other malfunctions in the components themselves. When one of these electric components malfunctions, the large amount of voltage and current flowing through the components causes heat buildup within the cabinet and ultimately can ignite a fire within the cabinet, which then may spread to nearby building structural components and create a fire hazard.

#Although smoke alarms are required to be in every residential or commercial building by the majority of local building codes, these smoke alarms often do not provide adequate protection against fires started in the electric panel cabinets. Specifically, smoke alarms are often not located near the electric panel cabinet, since the electric panel cabinet is typically located in a remote area of the building away from the normally occupied areas. Even if a smoke alarm is located near the electric panel cabinet, the smoke alarm typically reacts only after a fire has started and a sufficient amount of smoke has been produced. In an electric panel cabinet, an overheat condition may exist for hours or even days before smoke is present to trip a smoke alarm. Thus, an opportunity exists to activate an alarm before a fire starts by sensing an overheat condition occurring within the electric panel cabinet. Additionally, since many smoke alarms in commercial buildings are connected to the building's electrical system, a fire started in the electric panel cabinet can cause a loss of electric power, which then disables the smoke alarm.

#The drawings illustrate the best mode presently contemplated of carrying out the invention.

#In the drawings:

#FIG. 1 is a general isometric view of the heat alarm of the present invention as mounted to an electric panel cabinet;

#FIG. 1 shows a heat alarm 10 of the present invention as mounted to a conventional electric panel cabinet 12. The electric panel cabinet 12 typically encloses a variety of components used in routing electric power through a building, such as circuit breakers, fuses, and bus bars. Although the heat alarm 10 is shown as mounted to the top of the electric panel cabinet 12, the heat alarm 10 can be mounted to other areas of the cabinet 12, such as either one of the sidewalls or the front face.

#The heat alarm 10 generally includes a box-like enclosure 14 having a front face 16. As shown in FIG. 4, the enclosure 14 includes a removable battery cover 18 that provides access to a battery 20 mounted within an upper compartment defined by the interior of the enclosure 14.

#Referring now to FIG. 2, the heat alarm 10 includes a mounting arrangement 21 for attaching the heat alarm 10 to the electric panel cabinet 12. In the preferred embodiment of the invention, the mounting arrangement 21 includes an externally threaded rigid conduit nipple 22 extending through a bottom wall 24 of the enclosure 14. The nipple 22 includes a top flange 26 that prevents the nipple 22 from completely passing through an access opening 27 in the bottom wall 24. The heat alarm 10 is attached to the electric panel cabinet 12 by passing the threaded nipple 22 through a knockout opening 28 in a top wall 30 of the electric panel cabinet 12.