Abstract: A duct heater has a unique and symmetric arrangement of an auto limit and a pair of back up limits to permit the duct heater to be mounted in a duct in a number of different orientations. The duct heater can include a diffuser screen and have a particular size with respect to an upstream piece of equipment such as a single duct variable air volume damper box so that it can be used in these types of applications as well as stand alone applications in a duct.

Abstract: A silicone band heater assembly includes a silicone heater cable, lead wires, and a zip tie connection. The heater cable consists of a resistance heater wire that is optionally surrounded by a fiberglass braid, which in turn is encased in a silicone insulator. Each end of the heater cable includes an overmolded zip tie segment, which includes the splice connection between the lead wire and resistance wire, and the ability to link the ends of the heater cable assembly together when being clamped to a desired structure.

Abstract: An electrical resistance heating assembly comprises a heater ribbon woven through a first mica board. The heater ribbon extends upwardly from a top surface of the first mica board to provide heat to a fluid passing over the upwardly extending heater ribbon. The heat ribbon on an underside of the first mica board is electrically isolated by a second mica board positioned adjacent the first mica board. The first and second mica boards are held together with by a clamp-containing metal place positioned adjacent the second mica board with the clamps bent over the first mica board to keep the mica boards together.

Abstract: An open coil electrical resistance heater subassembly for use in a heater has a support plate dividing the heater into at least two portions. At least two resistance wire coils are supported on the support plate using a plurality of insulators. Each insulator is configured to provide support to a portion of the resistance wire coil. The at least two resistance wire coils are arranged with respect to the support plate so that the coil power for each coil is distributed generally evenly between the top and bottom of the support plate and across the width of the support plate.

Abstract: An electrical resistance heater assembly includes a heater housing forming a channel having a longitudinal axis for a fluid such as air to pass through and a heater support plate forming first and second levels in the heater housing. A first mica board assembly supporting a ribbon heater is mounted to the heater support plate at the first level and a second mica board assembly supporting a ribbon heater is mounted to the heater support plate at the second level. The first level is positioned adjacent an inlet of the heater housing and the second level is positioned adjacent an outlet of the heater housing. The first level and a side of the heater housing form a passageway for air to enter the heater housing and be directed to the ribbons of the second level, thereby allowing air to bypass the heater ribbons of the first level.

Abstract: An open coil electrical resistance heater employs an insulator having a coil convolution engaging portion that is adapted to engage heater coils with small diameters, small wire diameters, and/or small pitches without distorting the coil and compromising heater performance.

Abstract: A silicone band heater assembly includes a silicone heater cable, lead wires, and a zip tie connection. The heater cable consists of a resistance heater wire that is optionally surrounded by a fiberglass braid, which in turn is encased in a silicone insulator. Each end of the heater cable includes an overmolded zip tie segment, which includes the splice connection between the lead wire and resistance wire, and the ability to link the ends of the heater cable assembly together when being clamped to a desired structure.

Abstract: A close quarter electric resistance heater comprises a ribbon heater element that is woven between ribbon support segments and within a heater shell. The ribbon support segments form an annulus on each end of the heater and are linked to each other using connectors. The connectors space the ribbon support segments apart from each other to facilitate the weaving of the ribbon element along the inside of the heater shell for heating purposes. The connectors also link the ribbon support segments to the shell. The ribbon heater element has faces that are wider than its edges and the ribbon heater element is woven on the support segments such that the edges face the heater shell. This configuration minimizes the migration of the ribbon heater element towards the shell and possible short circuiting of the heater.

Abstract: A duct heater has a unique and symmetric arrangement of an auto limit and a pair of back up limits to permit the duct heater to be mounted in a duct in a number of different orientations. The duct heater can include a diffuser screen and have a particular size with respect to an upstream piece of equipment such as a single duct variable air volume damper box so that it can be used in these types of applications as well as stand alone applications in a duct.

Abstract: An open coil electrical resistance heater employs an insulator having a coil convolution engaging portion that is adapted to engage heater coils with small diameters, small wire diameters, and/or small pitches without distorting the coil and compromising heater performance.

Abstract: A mica board heater has a mica board support plate assembly that isolates the mica boards from the frame of the heater. The mica board support plate assembly includes a mica board with openings sized to receive ends of the mica boards that support the resistance wires. The mica board with the specially sized openings is supported by a frame that is attached to the heater frame. By using the mica board support plate assembly, the mica boards are electrically isolated from the frame and without compromising the structural soundness of the frame.

Abstract: An electrical resistance heating assembly comprises a heater ribbon woven through a first mica board. The heater ribbon extends upwardly from a top surface of the first mica board to provide heat to a fluid passing over the upwardly extending heater ribbon. The heat ribbon on an underside of the first mica board is electrically isolated by a second mica board positioned adjacent the first mica board. The first and second mica boards are held together with by a clamp-containing metal place positioned adjacent the second mica board with the clamps bent over the first mica board to keep the mica boards together.

Abstract: A multiple stage open coil electrical resistance heater uses a unique coil configuration on either side of a dividing support plate so that the air passing through the heater is heated uniformly when one or more stages of the heater are energized. The coil configuration also creates a termination zone on one side of the heater so that the terminations of the coils can be situated on the cool side of the heater. The heater coils also includes specially configured terminals to facilitate connection to power using an elongated member such as a stud or bolt.

Abstract: An electrical resistance heater assembly includes a heater housing forming a channel having a longitudinal axis for a fluid such as air to pass through and a heater support plate forming first and second levels in the heater housing. A first mica board assembly supporting a ribbon heater is mounted to the heater support plate at the first level and a second mica board assembly supporting a ribbon heater is mounted to the heater support plate at the second level. The first level is positioned adjacent an inlet of the heater housing and the second level is positioned adjacent an outlet of the heater housing. The first level and a side of the heater housing form a passageway for air to enter the heater housing and be directed to the ribbons of the second level, thereby allowing air to bypass the heater ribbons of the first level.

Abstract: A foldable electric resistance heater comprises at least a pair of insulator plates with a resistance wire threaded through openings in the insulator plates. In one mode, the insulator plates are folded with respect to each other and fastened together using one or more fasteners. In another mode, the plates can have other angled configurations with respect to each other. One or more insulators is positioned between the folded plates or adjacent the plates to isolate the resistance wire. The folded plate configuration and resistance wire provide significant advantages in manufacturing costs while forming a more robust heater configuration.

Abstract: An open coil electrical resistance heater uses a number of offset insulators to support the coil of the heater. The offset insulators configure the run of coil in a sinusoidal shape to hold the insulators in a more secure manner and reduce vibration and noise generation during heat operation. The sinusoidal configuration of the coil also reduces the problem of shadowing of portions of the resistance wire coil.

Abstract: A metal sheathed heater includes a solid state control device that allows the metal sheathed heater to be more efficiently operated. The control device supplies or terminates power to the heater according to certain conditions. Further, the control device uses predetermined time periods to control power to the heater. Thus, the heater is not kept on unnecessarily.

Abstract: A metal sheathed heater includes a thermostat, a means for mounting the thermostat in a secure location, and a joint interconnecting the thermostat with a source of power and a lead wire of the metal sheathed heater. The joint is a type that is moisture and abrasion resistant, mechanically strong, and electrically insulating.

Abstract: A metal sheathed heater utilizes splice connections that connects ends of a heater cable with ends of a lead wire. Each splice connection has a connector that connects core wires of the lead wires and heater cable together. Heat shrinkable tubing surrounds the connector and ends of the heater cable and lead wires. An adhesive is interposed between the heat shrinkable tubing and heater cable and lead wire ends to bond with the heat shrinkable tubing and complete the splice connection. The metal sheath of the heater can be formed with an enlarged diameter portion to account for the heat shrinkable tubing surrounding the lead wire and heater cable ends.

Abstract: An open coil resistance heater assembly is made for universal mounting between left and right hand installations in an appliance or other equipment. The heater assembly has its coils arranged symmetrically about a bisecting plane of the heater assembly and/or a center line of its terminal assembly aligned with the bisecting plane. The symmetrical coil arrangement and/or bisected terminal assembly allow the heater to be used in right hand or left hand installations.