Introduction to RAC

Introduction to tread

National council for vocational training (NCVT) and its certification procedure

Refrigeration

Air conditioning

History of refrigeration and air conditioning

Accidents at workplace

Various safety signs

First aid

Safety precautions while using hand tools

Common Hand Tools

Refrigeration tools

Fitting tools

Sheet metal tools

Welding tools

Fitting and Sheet Metal

Drilling machines

Grinding machine

Precision measuring instruments

Sheet metal joints

Rivet and riveting

Sheet metal operations

Basic Electric Concepts

Electrical terms

Safety precautions

Voltmeter

Ammeter

Ohmmeter

Multi meter

Wattmeter

Energy meter

Frequency meter

Earthing

Wiring test

Conductors

Insulators

Semiconductors

Differences among conductor, insulator and semiconductor

Alternating Current Circuit

Inductor

Capacitors

Effects inductor in an ac circuit

Effects of capacitor an ac circuit

Impedance

Power factor

Power factor improvement

Electric supply system

Terminologies related to three phase system

Winding connections

A.C. Motors

Definition of a. c. motor

Advantages of a. c. motor over d. c. motor

Synchronous motor

Asynchronous motor

Single phase induction motor

Phase splitting theory

Terminologies related to single phase induction motor

Types single phase induction motor

Universal motors

Repulsion motor

Electric motors used in refrigeration and air conditioning

Changing the direction of rotation of induction motor

Centrifugal switch

Starter

Capacitor

Comparison of torque of single phase a. c. motors

Faults, causes and remedies in electric motors

Basic Electronics

Semiconductor

N – Types semiconductor

P – Types semiconductor

P – N junction diode

Special types of diodes

Zener diode as a voltage regulator

Rectification

Transistor

Photo transistor

Amplifier

Multi vibrator

Integrated circuit – IC’S

Silicon controlled rectifier, SCR

UNI – junction transistor

RL – circuit

RC – circuit

Welding Techniques

Basic principle of welding

Electric arc welding

Gas welding

Oxy – acetylene gas welding

Filler rod

Joint strength

Oxy – acetylene cutting

Soldering

Brazing

Differences between soldering and brazing

Gases used in soldering and brazing

Uses of welding

Advantages of welding

Disadvantages of welding

Safety precautions for arc welding

Safety precaution for oxy – acetylene welding and cutting

Safety precautions for gas cutting

Basic Refrigeration

Principle of refrigeration

Units of refrigeration

Instruments used in refrigeration

Types of refrigeration

Science related to refrigeration

Work

Power

Energy

Pressure

Heat

Temperature

Differences between temperature and heat

Thermodynamics

Superheating

Sub cooling

Saturation temperature

Refrigeration Systems

Vapour compression refrigeration system

Vapour compression refrigeration cycle

Vapour absorption refrigeration systems

Electrolux refrigerator or three fluids refrigeration system

Refrigerators

Single door refrigerator

Gasket

Refrigerator door

Heat insulation materials

Poly urethane foam insulation

Types of refrigerators

Electric component used in refrigerator

Importance of flushing in evaporator and condenser

Necessity of replacing capillary tube and drier

Charging of refrigeration and extraction of air (evacuation) in refrigeration systems

Methods of leakage testing

Refrigerants used in refrigeration

Care and maintenance of single door refrigerator

Common faults in refrigerator and their causes and remedies

Frost Free Refrigerator

Construction and working of 2- door refrigerator

Differences between conventional refrigerator and frost free refrigerator

3-Door refrigerator

Electrical accessories

Air duct circuit

Automatic defrosting system

Voltage calculation of refrigerator cabinet

Forced draft cooling tower

Installation method of refrigerator

Care and maintenance of frost free refrigerator

Compressors

Classification of compressors

Reciprocating compressor

Rotary compressor

Centrifugal compressor

Differences between reciprocating and centrifugal compressor

Single stage and multi stage compressor

Hermetically sealed and semi – hermetically sealed compressor

Scroll compressor

Swash plate compressor

Wobble plate compressor

Methods of fabrication

Compressor efficiency factor

Wet compressor

Oil or lubricants

Condensers

Working

Types of condenser

Effect of choked condenser

Descaling of condensers

Liquid receiver

Pump down System

Condenser capacity

Evaporators

Working of evaporator

Types of evaporator

Water cooler

Bottle cooler

Superheating in evaporator

Accumulator

Methods of defrosting

Heat exchanger

Expansion Devices and Driers

Expansion valve

Function of expansion valve

Types of expansion valve

Capillary tube

Drier

Refrigerants

Desirable properties of an ideal refrigerant

Classification of refrigerants

Ozone layer (protection) rule, 1996

Ozone rule, 2000

Montreal protocol

Phase out schedules of CFC and HCFC in India

Methods of leak testing

Substitution of CFC

Comparison of Refrigerants

Nomenclature of refrigerants

Retrofitting and Thermal Insulation

Need of retrofitting

Changing in components during retrofitting

Retrofitting process

Properties of hydrocarbon refrigerants

Thermal insulation

Types of thermal insulation

Specialties of ideal thermal insulation

Functions of thermal insulation

Properties of thermal insulating materials used in RAC

Motors Used in RAC

Motors used in RAC

Production of rotating magnetic field with three phase supply

Working principle of three phase induction motor

Types of induction motor

Comparison between squirrel cage and slipring induction motor

Starting of induction motor

Importance of phase sequence

Slip and rotor frequency

Torque

Faults caused in three phase ac motors

Window Air Conditioner

Construction

Working

Types of window A.C.

Care and Maintenance

Installation of window A.C. unit

Split A. C.

Types of split A.C.

Electrical components used in split A. C.

Leak testing, gas charging and evacuation

Testing components

Installation of split A.C.

Faults and three troubleshooting in split A.C.

Differences between window A.C. and split A.C.

Car Air Conditioning

Construction

Electrical circuit

Testing equipment's

Leak testing, gas charging and evacuation

Installation of car A.C.

Free wheeling

Care and maintenance

Faults occurred in car A.C. and three troubleshooting

Commercial Compressors

Types of commercial compressors

Volumetric efficiency

Capacity control of compressors

Compressors oil

Applications of commercial compressor

Cooling Tower

Types of cooling tower

Capacity of cooling tower

Cooling tower range

Cooling tower approach

Cooling tower efficiency

Water Treatment

Necessity of water treatment

Causes of water contamination

Formation of scale and sludge

Corrosion

Formation of algae and slime

Hardness of water

Pump

Fans

Expansion valves and evaporators

Functions of expansion valve

Types of expansion valve

Selection of expansion valve

Advantages of expansion valve

Disadvantages of expansion valve

Capillary tube

Evaporator

Defrost systems

Water or brine chiller

Brine used in the form of secondary refrigerant

Accumulator

Suction – liquid heat exchanger

Water Cooler, Bottle Cooler and Deep Freezer

Water cooler

Bottle cooler

Visible cooler

Electrical, mechanical and testing components

Application of water cooler

Deep freezer

Ice Machines and Plants

Ice cube machine

Ice candy plant

Ice cream plant

Walk – In Cooler and Reach –In Cable

Walk – in cooler

Reach – in cable

Cold Storage

Construction

Working

Electric circuit and control

Spoiling agent

Prevention of food items from spoiling

Temperature control of different places in cold storage

Types of cold storage

Specification of cold storage

Efficiency of cold storage

Capacity

Use of vibration eliminator and shock absorber

Mobile refrigeration in transport vehicles

Faults and their remedies in cold storage

Extraction of air (evacuation) pressure measurement and charging of refrigerant from cold storage

Deep freezing in cold storage

Freezing tunnel

Blast freezer

Applications of cold storage

Psychometric

Psychometric terms

Enthalpy of moist air

Psychometric chart

Requirements for human comfort

Central Air Conditioners

Fundamental principle of central A. C.

Construction

Working

Types of central A. C.

Faults in central A. C.

Care and maintenance

Fans

Air filter

Duct

Function

Types of duct

Duct materials

Duct designing

Duct insulation

Air distribution

Air handling unit

Duct A. C.

Electric circuit

Components unit in ducting

Fault detection

Package A. C. and Split Package

Construction of package A.C.

Working of package A.C.

Types of package A.C.

Package A.C. duct

Installation method

Capacity calculation

Care and maintenance

Application of package A.C.

Faults and their troubleshooting

Split package

Centralized or Industrial A.C.

Direct expansion system

Indirect chiller system

Humidification

Dehumidifier

Controls used in A.C. plant

Safety devices

Maintenance of centralized A.C.

Commercial A.C. Plant and chillers

Construction of commercial A.C. plant

Chiller

Modulating valves used for temperature control

Chilled pipe line

Variable refrigerant flow

Cooling tower

Heat load calculation in A.C. building

HVAC System

Automobile A.C.

Construction

Refrigeration cycle

Working

Magnetic clutch operation

Free wheeling

Effects of speed of engine

Faults in car A.C. and their troubleshooting

Differences between room A.C. and car A.C.