WorkCentre 3210/3220 Multifunction Printer Service Manual 2-15Theory of OperationHalogen Lamp■ Voltage■ 120V: 115 V ± 5%■ 220V: 230 V ± 5%■ Capacity: 750 Watt ± 25 W■ Temperature Distribution: 120%ThermistorThe Thermistor detects the temperature of the heating unit and feeds the datainto the main processor.ThermostatWhen the Heat Lamp becomes too hot, the Thermostat cuts off power to thelamp to prevent from overheating.Heat RollerThe Heat Roller transfers heat from the lamp to the paper. As the paperpasses between the Heat Roller and Pressure Rollers, toner is melted andpermanently fixed to the paper. The surface of the Heat Roller is coated withTeflon, so that toner does not stick to the surface.Pressure RollersThe Large and Small Pressure Rollers are made of a silicon resin and thesurface is coated with Teflon. When media passes between the Heat Rollerand the pressure rollers, toner is melted and permanently fixed to the surfaceof the paper.Safety FeaturesSeveral protection devices are used to prevent Fuser overheating:■ Hardware cuts off Fuser power when overheating is detected.■ Software cuts off Fuser power when overheating is detected.■ Thermostat cuts off main power to the lamp.Interlocks disable the Fuser, motors and Laser Unit.■ Fuser power is cut off when the front cover is opened.■ Fuser cover temperature is maintained at less than 80° F.
