WD Catalog 2018

Figure Index

Fig. No. AC/Heater Combo System Components

Page

1 2

AC/Heater Combo System Components .............................................. Intro-1 Typical Off-Road Installation .............................................................. Intro-2 Cab Temperature Range ............................................................................. 1-1 Heat Energy Movement - Summer/Winter ................................................ 1-2 Cab Temperature Parked - Summer/Winter .............................................. 1-3 Coolant & Refrigerant Flow Inside the Systems ....................................... 1-3 Heat Energy Radiation ............................................................................... 1-4 Thermometer - Dial Type with Probe ......................................................... 1-4 Fahrenheit/Celsius Conversion Chart ....................................................... 1-5 Change of State - Illustrated with Water ................................................... 1-5 Change of State - Effect on Refrigerant ..................................................... 1-6 Change of State - Inside AC System........................................................... 1-7 AC/Heater Mounting Locations .................................................................. 2-2 AC System Operation - Diagram ................................................................ 2-3 Compressor Operation ................................................................................ 2-4 Clutch Assembly (to Compressor) ............................................................... 2-4 Condenser Function .................................................................................... 2-5 Receiver Drier Cutaway View ..................................................................... 2-5 Expansion Valve - Block Type Cutaway View ............................................ 2-6 Evaporator Coil with Thermostat .............................................................. 2-7 Heater System Components ....................................................................... 2-8 Pressure Radiator Cap - Thermostat Positions ......................................... 3-2 Pressure Radiator Cap - Sealing Cooling System ..................................... 3-2 Cooling System Water Pump Cutaway View ............................................. 3-3 Heater Core .................................................................................................. 3-3 Heater System Ducts - Typical ................................................................... 3-4 Blowers and Motors - Various Types .......................................................... 3-5 Heater Control Panel - Typical ................................................................... 3-5 Heater System Water Valves - Air & Cable Control .................................. 3-6 AC System Pressures & Change of State ................................................... 4-2 AC System Pressure & Temperature Relationship ................................... 4-3 Compressor Function - Low & High Side ................................................... 4-4 Compressor Designs Illustrated ................................................................. 4-5 Compressor Output (Performance) ............................................................ 4-8 Clutch Function - Thermostat Control ....................................................... 4-9 Condenser Designs - Illustrated ............................................................... 4-10 Receiver-Dryer Function ........................................................................... 4-11 Accumulator Function ............................................................................... 4-13 Internally Equalized Valve Function ....................................................... 4-14 Expansion Tube Design ............................................................................. 4-14 Evaporator Coil Function .......................................................................... 4-15 Roof Top AC System Blower & Fan Assembly ......................................... 4-16 HVAC Blend Air Duct System Cutaway View ......................................... 4-17 HVAC Stacked Core Arrangement Cutaway View .................................. 4-17 HVAC System In-Cab Control Function .................................................... 5-2 Thermostat Controls Illustrated ................................................................ 5-3 Pressure Switch/Clutch Control -Accumulator System ............................ 5-4 Refrigerant Flow Controls Illustrated ....................................................... 5-5 Heater System In-Cab Controls ................................................................. 5-7 Coolant Flow Using “H” Type Water Valve ................................................ 5-8 Air Operated Controls Cutaway View ........................................................ 5-9 Thermal Limiter/Superheat Switch Function ......................................... 5-10 Control Switch Variations Illustrated ...................................................... 5-10 Electrical Relay & Resistors Illustrated .................................................. 5-11 Electrical Schematic for Roof Mount AC System .................................... 5-11 Combination Controls - Binary™ & Trinary™ Switch Function............ 5-12

1-1 1-2 1-3 1-4 1-5 1-6 1-7 1-8 1-9 2-1 2-2 2-3 2-4 2-5 2-6 2-7 2-8 2-9 3-1 3-2 3-3 3-4 3-5 3-6 3-7 3-8 4-1 4-2 4-3 4-4 4-5 4-6 4-7 4-8 4-9

1-10

4-10 4-11 4-12 4-13 4-14 4-15

5-1 5-2 5-3 5-4 5-5 5-6 5-7 5-8 5-9

5-10 5-11 5-12

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