Table of Content
 

 

Constructional details and application of pumps

  • Construction of centrifugal pump
  • Purpose of each part is as follows
  • Types of pumps and usage
  • Centrifugal pumps
  • Reciprocating pumps

Details of centrifugal pump

  • Working of centrifugal pump
  • Calculation of head
  • Frictional losses 
  • Selection of pump

Functions and applications of water valves

  • Purpose of water regulating valve
  • Types and functions of regulating valves
  • Electrically operated
  • Actuated by pressure
  • Thermostatic
  • Adjusting pressure regulating valve
  • Capacity and efficiency of the condenser
  • The ratio of heat rejection factor is
  • Heat absorbed by the refrigerant in the evaporator
  • Water line vales and their function s
  • Globe valve
  • Gate valve
  • Ball valve
  • Butterfly valve
  • Check valve
  • Lift check valve
  • Swing check valve
  • Iron flanged check valve
  • Function of the check valve

Fault diagnosis in water circulating pumps

  • Air in the suction line
  • What is NPSH ?
  • Vibration in pump

Package Air – conditioners

  • Safety controls
  • The function of components
  • Compressor
  • Condenser
  • Expansion
  • Evaporator
  • Blower
  • High pressure cut out
  • Low pressure cut out
  • Overload relay
  • Thermostat
  • Water flow switch
  • Air filter

Construction details of package A/C

  • Construction of package A/C
  • Air distribution systems
  • Heat load calculation
  • Dry bulb temperature
  • Wet bulb temperature
  • Relative humidity
  • Dew point
  • Grains of moisture
  • Heat load calculation
  • Heat conversion

Safety switches and controls used in package A/C

  • Water pressure cutout switch
  • Electrical overload (over current protector)
  • Refrigerant flaw control(thermostatic expansion valve)
  • Installation
  • Working
  • Adjustment

Duct system of package A/C

  • Duct work details
  • Proper care for duct for duct system
  • Air distribution

Package A/C faults and diagnosis

  • Problem tree (LP cutout)

Automobile air – conditioning

  • Automobile airconditioning
  • Basic components
  • Compressor
  • Purpose
  • details
  • condenser
  • purpose
  • details
  • receivers/dryers and accumulators
  • purpose
  • receiver/dryer
  • accumulator
  • thermostatic expansion valve/orifice tube
  • purpose
  • evaporators
  • purpose
  • details
  • basic control
  • control
  • compressor operating controls
  • ambient temperature switch
  • thermostatic switch
  • Low pressure cut off switch
  • High pressure cut off switch
  • High pressure relief valve
  • Pressure sensing (cycling) switch
  • Thermal limiter and superheat switch
  • Service tip
  • Evaporator controls
  • Pilot operated absolute valve(POA)
  • Valves in receiver
  • Evaporator pressure regulator (EPR)Valve
  • Evaporator temperature regulator valve(ETR)
  • Fan controls
  • Cooling fan temperature switch
  • High pressure fan switch
  • A/C ‘on’ fan switch
  • A/c fan control switch
  • Driveability compressor controls
  • Constant run relay
  • Time delay relay
  • Wide open throttle cut off switch
  • Low vacuum switch
  • Power brake time relay
  • Power steering pressure cut off switch
  • High coolant temperature switch(HCTS)
  • Anti dieseling relay
  • Safety precautions
  • AIR BAGS (supplementary restraints system SRS)
  • Electrical
  • Refrigerant circuit
  • Safe handling of refrigerant containers
  • Caution
  • Swash plate axial type compressor

Different controls of CAR A/C

  • Installation of car A/C
  • Belts used in A/C
  • Condenser
  • Evaporator
  • Expansion valve
  • Ducts
  • Fans
  • Electrical
  • Thermostatic switch
  • Battery
  • Blower motor
  • Blower switch
  • Thermostat
  • Electromagnetic clutch
  • HP switch
  • LP-switch
  • Writing circuit
  • Pressure operated hot gas BPv

Performance of auto a/c system and troubleshooting

  • Performance test

Vapor absorptions system

  • Vacuum
  • Principle
  • Introduction of refrigerator
  • Two step

Domestic absorption system

  • Function of continuous absorption type of refrigerators
  • Automatic defrosting

Air refrigeration

  • Air refrigeration for  Aircrafts
  • Simple Cooling system
  • Ice Manufacturing

Ejector refrigeration

Non conventional refrigeration

  • Thermoelectric refrigeration process

Introduction to central Air- conditioning system

  • Calculate heat load
  • Wall gain load
  • Air change load
  • Product load
  • Occupancy load
  • Equipment load
  • Definition of Air-conditioning
  • Refrigerating Piping

Central air-conditioning plant wiring circuit

  • Motor control equipment
  • Protective devices
  • Fuses
  • Thermal overloads
  • Control sequence
  • Interlocking circuit
  • Control Relay

Compressors lub oil circulation

  • Piston and connecting rod assembly
  • Shaft seal
  • Bellow type shaft seal
  • Diaphragm type seal
  • Servicing lubrication oil pump
  • Splash Method
  • Forced feed
  • Oil Separator
  • Suction valve lifting arrangements in compressor
  • Hot gas bypass method- Capacity control
  • Cylinder bypass method- capacity control
  • Whirl vein capacity for centrifugal compressor

Efficiency testing of compressor

  • Efficiency of a compressor
  • Mechanical efficiency
  • Compression ratio
  • Volumetric efficiency
  • Performance factor
  • Break horse power
  • Reciprocating Compressor as Vacuum pump
  • Checking of external drive compressor
  • Compressor testing methods
  • Types of Reciprocating compressor
  • According to the cylinder
  • According to the working
  • According to the method of compression of the gas
  • According to the number of times of compression of gas
  • According to the cooling the head of the compressor
  • Safety precautions

Water flow differential pressure in shell and tube condenser

  • Quantity of water required per ton of refrigeration in shell and tube water cooled condenser.
  • Condenser capacity
  • Calculation
  • Parts of a shell and tube water cooled condenser
  • Function of a shell and tube condenser

De-scaling in shell and tube condenser

  • Necessity of descaling
  • Method of descaling
  • De-scale the condenser tube side(inner)

Chilled water storage tank, pipes and insulation

  • Chilled water tank and lines
  • Purpose of insulation for chilled water
  • The types and methods of insulations

Fans and Blowers of AHU, FCU and Air washer

  • Use of Fans and Blowers
  • Types of Fans-Blowers in Air conditioning plant
  • Forward curved fans
  • Backward curved fans
  • Backward inclined fans
  • Radial blade fans
  • Belt tensions of the belt driven
  • Drive methods employed  in fan operation
  • Selection of Blower fan

Safety devices of compressor

  • High pressure safety cut-out
  • High pressure cut-out and functions
  • Types of pressure controller
  • Bellow type
  • Diaphragm type
  • Bourdon tube type
  • Range and differential of a pressure switch
  • Differential pressure controller
  • Use of safety valve of relied valve
  • Fusable plug
  • Oil pressure safety switch use

Seasonal shut-down, maintenance of central Air-conditioning plant

  • Important checks and starting procedures
  • Post start- up checks
  • Log sheets
  • Starting procedures
  • Daily
  • Weekly
  • Monthly
  • Quarterly
  • Yearly
  • Operating plant at design efficiency

Vacuumising and gas charging in central air-conditioning plant

  • Objectives
  • Describe the vacuum sing of the plant
  • Explain about charging to the system
  • Describe the final testing of efficiency and other maintenance
  • Vacuumising of the plant
  • Charging gas to the system
  • Testing efficiency and other maintenance

Cooling towers

  • Name the parts of a cooling tower fan gear box drive shaft and motor and explain the function
  • Describe the use of cooling tower fan and its arrangement
  • Name of the part
  • Function
  • Servicing of motor and electrical connections
  • Assembly process of cooling tower fan
  • Cooling water process
  • Cooling pond
  • Cooling towers
  • Open tower
  • Close tower
  • Spray cooling ponds
  • Natural draft cooling towers
  • Mechanical draft cooling towers
  • Forced draft cooling tower
  • Induced draft cooling tower
  • Algae
  • Limitations
  • Range
  • Approach
  • Drift loss
  • Evaporation loss
  • Blow down
  • Make up water
  • Efficiency
  • Fan guard
  • Pine wood-hand rail
  • Fan cylinder
  • Inlet tee
  • Air inlet
  • Ladder
  • Asbestos casing
  • Inspection door
  • Series grid fills
  • Asbestos cement louvers
  • Nozzles
  • Distribution box

Central A/C Duct systems

  • Objectives
  • Duct materials standards;symbols,joints
  • Duct drawing symbols
  • Duct joints/symbols
  • Two seam lock methods
  • Ducts grilles and diffusers
  • Ducts
  • Diffusers and grilles
  • Return air
  • Duct joints
  • Electrode humidifiers
  • Water atomising humidifiers
  • Necessity of de-scaling in chilled water coils
  • De-scaling inAHU & Air-Washers
  • The Arrangement of AHU in Air-conditioning plant
  • Fan Coil Units
  • Air-washer’s applications in Air-conditioning plant

Air-Distribution Balancing in Ducts at Air-conditioning plants

  • Statics pressure and air velocity
  • Air distribution – balancing in ducts
  • Duck works
  • Duck insulations
  • Diffusers & Grilles
  • Reading the Mechanical drawings
  • Common faults and remedies
  • Safety requirement of duct system

Apply for Certification

https://www.vskills.in/certification/Vskills-Certified-Refrigeration-and-Air-conditioning-Technician-Level-IV