Electrical heating device for heating e.g. surface of plant, has control box and cable fixed to ends of heating tube, respectively, where tube includes polymer layer with electrical conductive wires for conduction of electrical current

摘要

The device has a control box (7) i.e. polycarbonate plastic box, and an electrical power supply cable (9) fixed to ends of a rectangular shaped flexible plastic heating tube, respectively. The tube has an electrical isolating polymer layer (2) with electrical conductive wires (3, 4, 6) that are adapted for the conduction of electrical current. One of the wires is used for the supply of electrical heating resistors (5). Each resistor is constituted of a resistive heating element that is coated with an electrically isolating external layer (1) made of ceramic, polymer resin or glass.