GUARD AS 1124600 - Caterpillar

Layout of Heating System
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(1) Control panel (2) Fresh air filter (3) Sunlight sensor (4) Heater unit (5) Recirculation sensor (6) Recirculation filter (7) Fresh air sensorHeater Unit
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(8) Blow out port for vent (9) Suction port for outside air (10) Blow out port for defrost (11) Blow out port for foot (12) Heater assembly (13) Suction port for recirculation airSchematic Diagram of Coolant Lines
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(4) Heater unit (14) Heater core (15) Radiator (16) Heater return line (17) Heater supply lineThe heating system uses coolant from the engine cooling system. Coolant is always circulated through heater core (14) by the water pump. Dampers on either side of the heater core are actuated when the selected temperature requires heating in order to be attained. The selected temperature is relative to the sensed temperature in the cab. When the dampers open, air flows across heater core (14). The dampers adjust accordingly depending on the amount of warm air that is required to achieve the set point. When the air flows across the heater core, the air is heated very quickly. The heated air is blended with the other air in order to warm the discharged air. The warmed air is then discharged into the cab through the air outlets.The amount of increase in air temperature is controlled by the amount of air that flows across heater core (14). As the amount of air flow increases, the temperature of the air that is discharged increases. The blend of cool air and warm air contains a greater amount of warm air. The coolant continues to flow from the heater core to the engine cooling system.