SYSTEM COMPONENTS

CHAPTER 5 page 91C & 93 L

OBJECTIVES IDENTIFY AND COMPARE THE STATE

OF REFRIGERANT IN EACH SECTION OF A/C SYSTEM.

EXPLAIN PURPOSE OF SYSTEM COMPONENTS.

COMPARE THERMOSTATIC EXPANSION VALVE TO FIXED ORIFICE VALVE.

93C & 91L

ORIFICE TUBE SYSTEM

EXPANSION VALVE SYSTEM

OPERATION OF COMPONENTS

Compressor

Refrigerant Pump Increases Pressure

and Temperature Several Types Separates High and

Low sides of system Oil is stored in

crankcase (sump)

Compressor Malfunctions

Malfunctions evident following ways;– Noise– Seizure– Leaks– High inlet and low discharge pressure

Discharge Hose

CONTAINS HIGH PRESSURE. SYNTHETIC RUBBER WITH NYLON

BARRIER LINING. 13/32 ID. PREFORMED METAL ENDS WITH FITTINGS.

Condenser Liquefies heat laden vapor. Receives Maximum Air flow. Hot vapor enters top of condenser. Hot Liquid leaves bottom of condenser. Refrigerant flows through condenser

coils and transfers heat to coils and fins. Fins transfer heat to air passing over

them.

96C & 97C109L

Conventional Tube and Fin

Parallel Two Path. Mechanically expanded tube to fin joints. Circular Tubes.

Multi-Louver Fin Design

Manifolded Multi-path refrigerant flow.

Serpentine Tube and Center Condenser

Brazed tube to fin joints. Flat Tubes. Parallel two path flow.

Evaporator

Dehumidifies the airstream. Under ideal conditions, refrigerant boils to

complete saturation 3/4 of the way through Evaporator.

Flooded evaporator means is full of liquid refrigerant with no room for expansion.

Starved evaporator means all refrigerant is boiled in the first quarter of the evaporator.

100C & 110L

Receiver Drier

Located between condenser and metering device

Assures only liquid reached expansion valve

Contains a chemical drying agent (Desiccant)

96C & 110L

Hoses and Lines

NOTICE: Do not use wormgear style clamps for repairing leaks in Nylon barrier hose fittings. Always repair Nylon barrier hose with the appropriate bubble style crimp fitting.

103C98L -102L

Liquid Lines

Condenser to the metering device 5/16 or 1/4 inch ID. Made of rubber, nylon, copper, steel or

aluminum. Contains high pressure liquid! Has sight glass

Thermostatic Expansion Valve Located on inlet side

of evaporator. Used to control

evaporator temp. Variable orifice can

vary on pressure, temperature or both.

Can malfunction in open or closed position.98C

102L

H-Valve Is a Expansion

Valve: Chrysler 1979 and later.

Has internal sensing bulb for low side temperature.

Low Pressure Cut Out Switch for low R-12 Charge.

Thermostatic Switch Senses Evap temp to control clutch operation. 99C & 104L

Valves In Receiver (VIR)

Three different components– TXV– Receiver/Drier– Pilot-operated-

absolute suction throttling valve

Compressor runs all the time.

Page 95C

Orifice Tube

Calibrated Restrictor Different color = different Orifice size. Mesh Filter Screen. Meters refrigerant into evaporator as low

pressure liquid.100C & 105L - 107L

Accumulator

Located between evaporator and compressor.

Primary function is to separate the vapor from the liquid and oil.

Location for desiccant.

102C & 107L

That’s All Folks!!!