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