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Click Here for School Information & Registration Form RSES Technical Institute-2 Course Details Beginning with tools-of-the-trade this manual covers refrigeration system accessories, desiccants and driers, defrosting methods, refrigeration system controls and piping. It also includes instruction on compressor replacement and system evacuation, electric motors in refrigeration systems, motor capacitors and protectors, thermostats, relays, contactors and starters, test equipment and troubleshooting, pressure and enthalpy diagrams, psychrometrics, heat transfer and estimating heat loads, residential air conditioning, humidification and a review of safety codes.
· Lesson 1 - Trade Tools· Lesson 2 - Refrigeration System Accessories· Lesson 3 - Desiccants and Driers· Lesson 4 - Defrosting Methods· Lesson 5 - Refrigeration System Controls· Lesson 6-7 - Refrigeration System Piping (Parts 1 & 2)· Lesson 8 - Retrofits and Disposal Requirements· Lesson 9 - Compressor Replacement and System Evacuation· Lesson 10 - Motors· Lesson 11 - Electric Motors in Refrigeration Systems· Lesson 12 - Capacitors· Lesson 13 - Motor Capacitors· Lesson 14 - Motor Protectors· Lesson 15 - Low-Voltage Thermostats· Lesson 16 - Relays, Contactors, and Starters· Lesson 17-18 - Test Equipment (Parts 1 &2)· Lesson 19-21 - Troubleshooting (Parts 1, 2 & 3)· Lesson 22-23 - Using Pressure and Enthalpy Diagrams (Parts 1 & 2)· Lesson 24 - Moisture in Air· Lesson 25 - Calculating Cooling Loads· Lesson 26 - Psychrometrics· Lesson 27-28 - Heat Transfer (Parts 1 & 2)· Lesson 29-30 - Estimating the Heat Load (Parts 1 & 2)· Lesson 31 - Room Air Conditioners· Lesson 32 - Types of Air Conditioning Systems· Lesson 33 - Residential Air Conditioning· Lesson 34-35 - Humidification (Parts 1 & 2)· Lesson 36 - Review of Safety and Codes
Objectives: Describe the operation, selection, and application of the following accessories: condensing water regulators, check valves, safety relief devices, discharge oil separators, liquid level indicators and moisture indicators, discharge mufflers, compressor lubrication protection controls, strainers and filters, vibration eliminators, suction-line accumulators, heat exchangers, receivers.
Objectives: State the purpose of a desiccant. Name and explain the ways in which a desiccant works. List three common desiccants used today. Describe the properties required of a desiccant. Define the terms mixed desiccants and solid-core desiccants. Identify the locations in which a drier can be installed, and explain the advantages and disadvantages of each. Describe the differences between a drier and suction-line filter. Explain what is meant by the term hydrophobic behavior of desiccants. State the principle on which all moisture indicators work.
Objectives: Identify various defrosting methods. Describe the basic operation of each method. Explain the advantages and disadvantages of each method.
Objectives: Identify typical operating and safety controls. Explain the difference between instrument differential and operating differential. Describe the operation of a float switch. Explain why pilot-operated TEVs are used on large systems. Describe the operation of a constant-pressure expansion valve. Explain the function of evaporator pressure regulators, suction pressure regulators, and condenser pressure regulators. Explain the need for both high-side and low-side float valves. Describe the operation of the various types of solenoid valves. Explain the function of a refrigerant reversing valve.
Objectives: Determine the maximum pressure drop for commonly used refrigerant piping. Describe various methods of ensuring the successful operation of an evaporative condenser. Explain the necessity of maintaining a minimum velocity in refrigerant piping. Calculate the subcooling necessary to prevent flash gas caused by static head. Describe ways in which liquid-line piping can improve the service of equipment. Explain how TEVs should be installed when evaporators are interconnected. Explain how to install sight glasses in liquid lines.
Objectives: Explain why pressure drop must be minimized in refrigeration piping. Lay out a basic piping plan. Determine the allowable pressure drop in refrigeration piping. Utilize common pipe sizing tables, charts, and graphs.
Objectives: Explain conversion procedures and describe the components that need to be checked. Determine whether a component needs to be replaced or adjusted. Adjust controls to their proper settings. Explain why the filter-drier is so important. Determine when you should contact a component manufacturer for assistance. State what records need to be kept and for how long. Describe the recovery and disposal process. Explain the proper method for disposing of waste oils and refrigerant oil filters. Define a “small appliance.”
Objectives: Describe the proper procedures for diagnosing compressor problems. Distinguish between mechanical failures and compressor burnout. Describe the proper procedures for replacing compressors. List and observe the necessary safety precautions. Explain what “dehydrating the system” means. Identify and describe the various methods of evacuation. Describe how a high-vacuum pump can be used to evaluate a system adequately. Define a micron. List the instruments used in the field to indicate high-vacuum conditions. Explain why the size of the connecting line between the vacuum pump and the system is so important.
Objectives: List the basic types of motors used in the HVACR industry. Describe some of the visual indications that identify defective motors. Explain the difference between fractional-horsepower motors and integral-horsepower motors. Determine the speed and rotation of a motor. Use appropriate test instruments to troubleshoot various types of motors and their associated starting circuits. Describe some of the causes of overheating in electric motors. Explain what causes single phasing in a three-phase motor. Calculate voltage and current imbalances in three-phase motors. Describe basic motor replacement procedures. Read a motor nameplate. Use NEMA data to determine motor frame sizes and dimensions.
Objectives: Explain the basic principles of operation of electric motors. Calculate motor speed and slip. Describe the characteristics of various types of single-phase ac motors including split-phase motors, capacitor-start motors, capacitor-start, capacitor-run motors, repulsion-induction motors, and shaded-pole motors. Explain the difference between single-phase and three-phase motors. List the three main types of three-phase squirrel-cage motors and describe the distinguishing characteristics of each. Identify the three main types of dc motors. Explain how current-type and voltage-type starting switches operate.
Objectives: Observe the proper safety precautions when taking capacitance readings. Explain the differences between start and run capacitors. Discharge a capacitor safely. Describe the four main problems or conditions that identify a faulty capacitor. Describe the operation of various types of instruments used for testing capacitors.
Objectives: Identify the two types of capacitors used with electric motors. Explain the difference between electrolytic and oil-paper capacitors. Explain how capacitors are rated. Calculate the capacitance for capacitors connected in series or parallel. Describe the operation of starting relays. List the main causes of start capacitor failure.
Objectives: Explain the function of a motor protector. Describe how an overload relay operates. Explain the function of a circuit breaker. Describe how external and internal protectors operate. Explain how protectors are used with motors.
Objectives: Describe the functions performed by low-voltage thermostats. Identify the various types of low-voltage thermostats. Define the terms setpoint, make point, break point, and differential as they apply to low-voltage thermostats. Explain how anticipation works. List the proper guidelines for installing and troubleshooting various types of low-voltage thermostats.
Objectives: List common causes of relay failure. Describe the physical indications that identify defective relays and contactors. Explain how to test pilot-duty relays and line-duty relays. Explain how to test contactors and starters. Explain how to test potential relays and current relays. Explain how to test time-delay relays.
Objectives: Describe the basic operation of the d’Arsonval meter movement. Explain the difference between analog and digital measuring instruments. Distinguish between voltmeters, ammeters, ohmmeters, and multimeters, and describe the operational principles of each. Explain how the sensitivity of a voltmeter is calculated. Describe how various electrical meters are used to measure resistance, voltage, and current, and to check for continuity. Demonstrate how clamp-on ammeters are used. Describe the basic operation of a Wheatstone bridge, and explain how it can be configured to act as a resistance bridge or a capacitance bridge.
Objectives: Explain the operation of a wattmeter. Demonstrate how to read a watt-hour meter. Describe how to determine the power factor of a circuit by using a power factor meter. Describe how a varmeter can be used in correcting power factor problems. Explain the purpose and use of various instrument transformers. Explain the operation of megohmmeter. Explain the purpose and use of various recording instruments. Describe how a compressor analyzer can be used in troubleshooting.
Objectives: Conduct a customer interview. Identify the instruments required for performing specific troubleshooting tasks. Follow step-by-step procedures in analyzing a problem. Describe the most common causes of system malfunctions.
Objectives: Explain the need for following safe procedures when troubleshooting electrical problems. Plan and carry out an orderly course of action for diagnosing and correcting electrical problems. Describe some of the most common electrical problems encountered in HVACR systems.
Objectives: Diagnose compressor malfunctions. Evaluate compressor performance by using external testing devices. Identify possible causes of compressor failure by learning about inspection of internal components.
Objectives: List five properties of a refrigerant that must be understood in order to interpret a pressure-enthalpy diagram. Explain superheated gases and vapor pressure. Define the terms enthalpy and entropy. Determine evaporator pressure and condensing pressure using the pressure-enthalpy diagram. Calculate compression ratio, net refrigeration effect, and other values, using the pressure-enthalpy diagram.
Objectives: Describe how to use pressure-enthalpy diagrams for estimating energy requirements. Explain compressor power. Describe the effects of lower condensing temperature, liquid subcooling, and suction vapor superheating.
Objectives: Describe the chemical makeup of dry air and explain what is meant by “wet” air. State Dalton’s Law and Boyle’s Law. Define the terms density and specific volume. Explain the difference between relative humidity and absolute humidity. Define the terms dew point and specific humidity. Explain the difference between sensible heat and latent heat. Explain the meaning of “dry-bulb” and “wet-bulb” temperatures. Use the appropriate tables to make calculations and solve practical problems relating to the condition and behavior of air.
Objectives: Define many of the key technical terms used in air conditioning. Explain the various factors that determine air conditioning cooling loads. Obtain information from a variety of tables and other reference sources and use such data to estimate air conditioning requirements.
Objectives: Define the following terms as they apply to the study of Psychrometrics: sensible heat, latent heat, barometric pressure, density, dew point, relative humidity, specific humidity, specific volume, and enthalpy. Explain how to use psychrometric tables and charts to find various properties of air.
Objectives: Explain the basic principles of heat transfer. Name the three methods of heat transfer and give examples of each. Describe the factors that affect the rate at which heat is conducted. Define the four heat transfer values (the K-value, the C-value, the R-value, and the U-value), and explain how they are used. Explain the relationship between temperature and density.
Objectives: State the purpose of insulation, and explain the role that insulation plays in conserving energy in refrigeration and air conditioning applications. Describe some of the ways in which moisture can infiltrate insulation. Describe the effects that moisture has on insulation. Explain how partial pressure differences affect the placement of vapor barriers. Explain what causes “sweating.” List some of the characteristics of a good insulation, and describe each. Explain how the amount of insulation required for a given application is determined.
Objectives: List the four sources that contribute to the total heat load in any application. Explain how to calculate the heat leakage load. Use tables to determine the product load. Calculate the miscellaneous heat load produced by lights, motors, human occupants, etc., in a refrigerated space.
Objectives: Explain the relationships among the various heat transfer factors. Explain how surface film conductance affects the transmission of heat. Interpret outdoor design data for various locations as provided in published tables. Describe the effect of the sun’s rays on heat loads. Identify sources of air infiltration, and compute the rate of infiltration. Use published data to determine product loads. Define the latent heat of fusion. Identify supplementary loads and sources. Evaluate the selection of a compressor based on hourly load calculations. Calculate the total refrigeration load for a refrigerated space.
Objectives: Size a room air conditioner properly. Estimate cooling loads. Select a suitable room air conditioner based on the estimated cooling load. Make a thorough pre-installation survey to ensure the compatibility of the selected unit with the customer’s electrical system. Choose the proper location for the installation of a room air conditioner. Diagnose a malfunctioning room air conditioner correctly. Test the refrigerant charge of a room air conditioner.
Objectives: Identify the major types of air conditioning systems. Explain how single-zone systems differ from multizone systems. Describe the basic operation of variable air volume (VAV) systems. Explain how induction systems work. Describe the various configurations of air-water systems. List five kinds of multiple-unit systems.
Objectives: Evaluate residential forced-air heating systems for compatibility with add-on cooling. Make the necessary calculations to determine whether the blower capacity is sufficient to handle both heating and cooling. Check temperature rise and duct static and use the proper graph to determine the flow rate of air through a duct system. Describe the factors that must be considered when planning the addition of an air conditioning evaporator coil to a forced-air furnace. Locate outdoor condensing units properly.
Objectives: Use the proper terminology in discussing humidification. Identify the proper humidity levels for comfort and health. Measure humidity levels correctly with instruments. Size and select a humidifier.
Objectives: Add moisture to air by various methods. Install a humidifier properly. Control the humidity level properly.
Objectives: Adhere to personal safety practices and proper equipment safety practices. Comply with federal, state, and local safety codes and regulations. |
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