Certified Car AC Mechanic

TABLE OF CONTENT

Safety

• Safety Precautions
• Introduction
• Air Bags (Supplementary Restraint system SRS)
• Electrical
• Refrigerant circuit

Various factors in Refrigeration Cycle

• All matter can be in any 3 states
• Methods of Refrigeration
• Basic Refrigeration Cycle
• Description of each phase as follows
• Condensation
• Expansion
• Vaporization
• Ton of Refrigeration
• Example
• Solution
• Ambient temperature
• Example
• Heat of Compression

Refrigerant & Oils

• Refrigerants
• Refrigerants over the years
• Identifing Refrigerants by number
• Refrigerant-12(R-12)
• Refrigerant-R-22
• Refrigerant-R-134A
• Other numbering codes
• Refrigerant are also classified according to three levels of Toxicity & Flammability
• Flammability
• Other Classifications
• Primary Refrigeratants
• Desirable Properties of refrigerants
• Environmental Impact of CFC & Other Refrigerants
• Ozone Depleting Potential ( ODP)
• R12 and R134A
• Warning- Do not mix R12 With R134a. Make Sure you use the proper Oil
• Purpose of A/C Refrigerant
• Safety Rules for refrigerant
• Importance of oil
• Double End Capped (DEC) PAG and mineral Oils

Identification of compressor

• Compressor
• The function of reciprocating compressor
• The function of swah plate compressor
• Purpose

Identification of mechanical devices used in car air conditioning unit

• Compressor
• Condenser
• Type of Condensers
• Receiver-Drier
• Evaporator
• Accumulator
• Refrigernatlines
• A/C Blower motor
• DUCT System

Identification of control devices of car air- conditioning cost.

• Compressor Clutch control
• Function of clutch coil
• Function of dual pressure switch
• Function of Thermo stable expression valve and orifice tube
• Purpose- HP
• Working
• Orifice tubes
• Function of thermostat
• Thermostat control

Identification of safety devices at car air conditioning unit

• Compressor operating controls
• Ambient Temperature Switch
• Thermostatic Switch
• Low pressure cut off switch
• High pressure relief vaive
• Pressure Sensing (Cycling) Switch
• Thermal limiter and superheat switch
• Evaporator controls
• Pilot Operated Absolute Valve (POA)
• Valves in Receiver (VIR)
• Evaporator Temperature Regulator Valve (ETR)
• Cooling Fan Temperature Switch
• High pressure fan switch
• A/C ‘ON’ fan Switch
• A/C fan control switch
• Driveability Compressor Controls
• Wide open throttle cutoff switch
• Wide open throttle cutoff switch
• Low vacuum switch
• Power Brake time relay
• Power Steering pressure cutoff switch
• High Coolant Temperature Switch (HCTS)
• Anti Dieseling Relay
• Anti Dieseling relay

Function of Car Air conditioning system

• Compressor
• Condenser
• Discharge line
• Receiver driver
• Evaporator Expansion value
• Liquid line
• Blower fan A
• Suction line
• Radiator line
• Here’s now an air conditioning system and its component work
• Features : Displacement (cc) 161 161 Displacement*
• Details Product Description Specification:

Types of current

• Types of electrical supply ( Voltage )
• Type of current
• AC supply
• Alternative voltage

Identification of instruction from the data given on the dial

• Data contained on the measuring instrument dial
• Measuring range and measuring units
• Types of current

Multimeter

• Types of Multimeter
• Multimeter as a DC voltmeter
• Multimeter as a DC ammeter
• Multimeter as an ohmmeter
• Multimeter as a AC voltmeter
• Method of measuring DC voltages
• Method of measuring AC voltage
• Method of measuring resistance
• Method of use
• Application of a multimeter
• Types of multimeter

Measuring voltage and current using multimeter

• Multi – range meter
• Meter scale of multi – range meter
• Multi – meter
• Identify the scale to take reading
• Multimeter as DC VOLMETER
• Multimeter as DC AMMETER
• Multi – meter as AC VOLMETER
• Multi – meter as AC AMMETER
• Multi – meter as OHMMETER
• Resistance zero setting

Electrical Part of an air conditioning in car

• The main electrical parts where as follows
• Parts used in the system
• Various parts are connected into the circuit
• Electrical circuits

Inspection of the car Air conditioning system

• VISUAL INSPECTION OF SYSTEM
• OPERATING INSPECTION OF SYSTEM
• CHECKING SYSTEM FOR FULL CHARGE
• CHECKING RELATIVE TEMPERATURES HIGH AND LOW SIDES OF SYSTEM

Recovery

• Reason for Recovering Refrigerant
• Definitions
• Method of Recovery
• Passive method
• Charge migration
• Use of System’s Compression Compressor
• Active Method of Recovery
• Vapor Recovery
• Liquid Recovery

Retrofit CFC Filled car A/C with HFC

• Retrofitting of CFC filled car a/c equipment with the HFC 134a refrigerant
• Need to Retrofit CFC filled car a/c with HFC 134a and its advantages
• Precaution to be taken when retrofitting CFC filled refrigerator with HFC – 134a

Evacuation of the Refrigeration System

• Evacuation
• Why Evacuate
• How do we evacuate the system
• Boiling point of water at various pressures
• Need for a vacuum pump
• What type of vacuum pump?
• Construction of two stage Rotary Vacuum Pumps
• Rotary Pumps
• Rotary vane Pumps

Charging Refrigerant in a system

• Refrigerant charge quantity
• Charging by liquid or vapor
• Vapor charging
• Liquid charging
• Charging Accurately
• Refrigerant Charging
• Charging with a charging cylinder
• Charging by weight
• Charging by sight glass
• Charging refrigerant using frost line method

Performance of Auto A/C system

• Check performance
• How to read the graph
• Example

Maintenance

• Periodic maintenance
• Review of Safety

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