Learn/NECO SSCE/Syllabus/WeldingStudy this course in LearnPractice opens in your NECO SSCE workspace after you sign in. Questions and lecture notes stay there.Practice this courseOpen lecture notesOfficial rules, eligibility, and dates stay on the NECO SSCE guide.course outlineSafety and first aid in the workshop.Workshop rules and regulationsSafety devices/equipment – helmet, goggles, safety boots, hand gloves, overall, apron sand bag, fire extinguishers, etc.Accident: causes and prevention techniques.First Aid - materials for First Aid, charts, posters and first aid box, etc.Application of first aid materials.Energy, matter and power.EnergyThe process of energy conversion electrical to mechanical, gas to vapour, mechanical to heat.Meaning of internal energy.Enthalpy of a fluid substance, its pressure, volume and temperature of internal energy.Nature of matter.The ph diagram of refrigerant.State of matter – solid, liquid, gas or vapour.Change of state of matter.power.The meaning of power.Calculation of power used by a compressor.Unit of power: watts and kilowatts unit of heat: joules and kilojoules.Temperature and pressure.Temperature and its measurementConcept of temperature.Different types of thermometer e.g. gas, resistance, liquid and thermocouple.Temperature scale conversionInternational practical temperaturePressure and its measurementConcept of pressureDifferent types of pressure measuring devices e.g. barometer, manometer, bourdon tube gauge.Pressure measurementUses of suction and high pressure gauges.Effects of temperature, pressure and volume in refrigeration and air conditioning systems.Gas law, Boyles law, Charles law and Dalton's law.Calculations involving general gas law. Formulae:-Plotting various temperature scalesRefrigeration and air conditioning systems.Introduction to refrigeration.Refrigeration cycle – Evaporation, compression, condensation and expansion.Layout diagram of refrigeration systems.Types and applications of the various forms of refrigeration.Principles of operation of forms of refrigeration system.Functions of the component and accessories e.g. relay, solenoid valves, capacitors and thermostat.RefrigerantsDefinition and types of refrigerantsChemical names and formulae.Properties and uses of refrigerants.Refrigerants flow controls e.g. TEV, AEV, capillary tube.Operations of refrigerant flow controls.Air-Conditioning processesPsychometric properties of air.The processes of air conditioning: heating and cooling.Latent and sensible heat, saturated and super-saturated vapour.Compressors, Condenses and EvaporatorsCompressorsTypes of compressorsConstruction of compressors.Working principles of compressors.Condensers.Construction of condensers.Calculation of heat load on condensers.Types and functions of liquid receiver and service valves.Principle of operation of liquid receiver and service valves.Types of evaporators.Construction and services of evaporators.Working principles of evaporators.Heat load estimates on evaporators.Workshop practices.Basic tools used in refrigeration and air-conditioning workshopsBasic tools – hacksaw, coil spring benders, reamers, tube cutters, etc.Fault diagnosis and trouble shooting.Tools and procedures for servicing window unit air-conditioner.Different methods of diagnosing faults systematic and observation.Common faults in refrigeration systems and their symptoms – leakage, faulty units, faulty compressor, poor cooling and current leakage.Maintenance and TestingTechniques of effective repairs in refrigeration and air-conditioning systems.Techniques of trouble shooting in a given system.Testing for leakages, polarity, insulation continuity, pressure and efficiency.Maintenance of compressors, evaporators, motors, condensers, valves, accumulators and contactors.Installation processesPiping, Ducting and TrunkingConcept of piping, ducting and trunking.Piping a condenser and an evaporator.Ducting, trunking and installation of air-conditioners.Piping, ducting and trunking tools – mallet hammer, flaring tools, silver tape, dot-punch, bending spring, amaflex, hacksaw, PVC pipes.Motors and generatorsTypes, functions, operations and application of motors and generators.Installation procedures for motors and generators.Maintenance of motors and generators in a refrigeration system.Cold roomWorking principles of cold room.Cold room installation procedures.Factors affecting cold room operations.Insulation processesInsulation of refrigeration and air-conditioning system.Importance of insulation of refrigeration and air-conditioning systems.Types of insulating materials – glasswool, fibre glass, polysterene foam, wood, bitumen, ceramic, etc.Functions and properties of insulation materials.Procedure for insulating refrigeration and air-conditioning systems.Entrepreneurship.Business concept.Concept of business enterprise and types of businesses – sole proprietorship, partnership, limited liability, etc.MarketingSources of finance – loan, mortgage, shares, overdrafts, savings, etc.Types, functions of marketing styles.Meaningful marketing at the least cost.Marketing protocol and cost.AccountingPrinciples of Accounting.The concept of business as a separate entity.Ledger, trial balance and balance sheet.
