Certified Refrigeration and Air-conditioning Technician Level-II

TABLE OF CONTENT

​Study of frost free refrigerator

• Define conventional refrigerator
• Define frost free refrigerator
• Features of the household refrigerator

Refrigerator system of frost free refrigerator

• Construction of the free refrigerator
• Compressor
• Parts of a conventional refrigerator
• EVAPARATOR

Electrical components and their function in a frost free refrigerator

• Deforst Timer
• Defrost Heater

Study of wiring, Automatic defrost, heater, Timer fan motor and air duct system

• Electrical de-frost system
• Defrost Controls
• Damper control adjustment

Methodology of Retrofitting

• Retrofitting of CFC filled refrigerator with the HFC 134a refrigerator
• HFC’s advantage
• HFC’s disadvantage
• Precaution to be taken when retrofitting CFC filled refrigerator with HFC-134a
• Comparative study of components used for R-12 and R134a.

Details of CFC filled refrigerator with Hydro Carbon blend

• Retrofit CFC filled refrigerator with the HC refrigerant
• Refrigerator electrical devices using HC Refrigerants 
• Properties of HC refrigerant
• Precaution to be taken when retrofit CFC filled refrigerator with HC blend refrigerants
• Care of handling with hydro carbon cylinders

Refrigerators using different refrigerants

• The service, components and replacement in HC refrigerator
• Comparative study on performance of refrigerator

Introduction of Air-conditioning

• Past Air-conditioning equipments
• Present Air-conditioning equipments
• Future Air-conditioning equipments

Air-conditioning fundamentals

• Air conditioner

Constructional details of window Air-conditioner

• Main components of window A/C
• Front grill
• Outer cover

Air -conditioning system

• Air movement in air conditioned area

Air – conditioning system

Electrical components of window air-conditioner

• Selector switch
• Thermostat
• Relay
• O.P.L
• Capacitors

Split Air-conditioning

• Types of split air-conditioner
• Condenser
• Expansion devices
• Liquid line drier filter
• Evaporator
• Liquid suction heat exchanger
• Suction line accumulator
• Fan, Fan motor, blower
• Refrigerant tubing
• Ventilation of room
• Drainage of condensate water
• Functions

Comparison, advantage and disadvantage of split a/c and windows a/c

• Importance points of spilt a/c
• Specification of spilt a/c
• Windows ac unit consist of following components
• Windows ac system

Air cooled condensers

• Use of condenser
• Fin type air cooled condenser

Constructional details and specification of air condenser

• Detail of air cooled condenser
• Selection of air condenser
• Fin is part of tubing
• Coiled wire uses as fin
• Circular fin
• Large multiple fin

Air Filters Their Types and Specification

• Know How To Clean The Air Filters
• Describe Types of Air And Their Specifications
• How to clean The Air Filters
• Types of Air Filters And Their Specifications
• Prefilters Fine Filters
• Filters And Maintenance of Filters
• Electronic Air Cleaners

Air Flow Measurements

• Explain Room Air Flows
• Room Units Air Flows

Velocity Meters

• Explain Air Flow Measurements
• Explain The Types of Anemometers
• Velocity And CFM
• Anemometer
• Rotating Vane Anemometer
• Deflecting Vane Anemometer
• Hot wire Anemometer
• Air Velocity at Various temperature
• Air Velocities Corresponding to Velocity Pressure

Principles of Pipe Sizing

• Explain Refrigerant Lines And Piping
• Describe Piping Materials
• Know General Design Consideration
• Understand Suction Line Size, Discharge Line Size
• Piping Materials
• Pipe Joints
• General Design Consideration
• Sunction Line Size, Discharge Line Size For Air –Condi- Tioners Are Given In Table

Study of Service Valves

• Describe The Service
• Understand The Service Valve Operation
• Use of Service Valve For Gas Charging
• Describe The Features of Split A/C System
• Explain About Selector Switch
• List The Different Models of Working In Split A/C
• The Working Principle of Split A/C

Defective Window Model Room Air –Conditioner – “Compressor Does not Start’’

• Analyse The Causes For The Complaint Compressor Does Not Start With The Help of Problem Tree
• Analyse The Causses For The Defect Leading  to The Complaint With The help of The Trouble Shooting Chart
• Analyse The Sequence For Repair Using The Service Flow Sequence
• Symptom : “ Compressor Does Not Start”

Defects in Window Model Air – Conditioner –  “Compressor Trips Frequently"

• Analyse The For The Complaint/Defect –Compressor Trips Frequently With The Help of Problem Tree (PT)
• Anlyse The Causes For The Defect Leading To The Complaint With help of Trouble Shooting Chart (TSC)
• Analyse The Sequence For Repair Using The Flow Sequence

Defects In Window Air –Conditioner -  “poor Cooling” – “Evaporator Coil

• Analyse The Causes (s) For The Cmplaint “Poor Cooling”- With The help of Problem Tree (PT)
• Anlyse The Cause (s) For  The  Defect Leading To The Complaint With The Help of Trouble Shooting Chart (TSC)
• Analyse The Sequence For Repair Using The Service Flow Seqence (SfS)

Defects in Window Air –Conditioner “Poor Cooling”- Unit Running Continuosly

• Analyse The Cause (s) For Complaint “Poor Cooling” –Unit Running Continuously With The Help Of “Problem Tree”(PT)
• Analyse The Sequence For Repairs Using The Servicing Flow Sequence (SFS)
• Symptom; “Poor Cooling

Defects in Split Type –Conditioner “Water Leakge In Indoor Unit” 

• Anlyse The Causes For The Defects “Water Leakage In Indoor Unit” With The Help of Problem Tree (PT)
• Analyse The Causes For The Defect Leading To The Complaint With Help of Troubleshoot Chart (TSC)
• Analyse The Sequence For Repairs Using The Service Flow Sequence (SFS)

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