TM-9-2320-280-20 HMMWV Technical Manual Unit Maintenance Volume 1 Download
Page 87 of 890
TM 9-2320-280-20-1 1-32. M997, M997A1, AND M997A2 AMBULANCE AIR-CONDITIONING SYSTEM OPERATION The air-conditioning system covered in this manual applies only to the M997, M997A1, and M997A2 vehicles and consists of the following major components: COMPRESSOR - Inside the compressor, low pressure gas refrigerant is compressed into a high pressure gas that is pushed into the condenser by the compressor. DISCHARGE LINE - High pressure gas is carried through the discharge line from the compressor to the condenser. CONDENSER - Refrigerant enters the condenser as a high pressure gas. When condensed, it gives up its heat to the outside air and becomes a high pressure liquid. LIQUID LINE - High pressure liquid refrigerant is carried back to the evaporator by the liquid line to repeat the evaporation/condensation cycle. EXPANSION VALVE - High pressure liquid refrigerant enters a non-adjustable expansion valve where the refrigerant is formed into a liquid spray. EVAPORATOR - Refrigerant enters evaporator as a liquid spray. It absorbs heat from the air in the patient compartment and vaporizes into a low pressure gas. SUCTION LINE - Refrigerant in low pressure gas form is drawn from the evaporator by the suction action of the compressor. 1-54