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.
COURSE LESSONS - SUMMARY
Lesson 1 -
· 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 &
· Lesson 8 - Retrofits and Disposal Requirements
Lesson 9 -
Compressor Replacement and System Evacuation
· Lesson 11 - Electric Motors in Refrigeration Systems
· Lesson 13 - Motor Capacitors
- Motor Protectors
· Lesson 15 - Low-Voltage Thermostats
- Relays, Contactors, and Starters
· Lesson 17-18 - Test Equipment (Parts 1 &2)
- Troubleshooting (Parts 1, 2 & 3)
· Lesson 22-23 - Using Pressure and Enthalpy Diagrams (Parts
1 & 2)
· Lesson 24 - Moisture in Air
- Calculating Cooling Loads
· Lesson 26 - Psychrometrics
- Heat Transfer (Parts 1 & 2)
· Lesson 29-30 - Estimating the Heat Load (Parts 1 &
· Lesson 31 - Room Air Conditioners
- Types of Air Conditioning Systems
· Lesson 33 - Residential Air Conditioning
- Humidification (Parts 1 & 2)
· Lesson 36 - Review of Safety and Codes
Lesson 1 - Trade Tools
Explain the importance of using proper tools and test instruments. List the various types of wrenches and describe their use.
Describe the proper procedures for bending, flaring, and swaging tubing. Describe the correct
use of pinch-off tools. Describe the proper techniques for soldering and brazing. Identify various types of diagnostic tools
and testing instruments. Identify various refrigerant charge tools and explain how they are used. Explain the reasons for
using safety goggles.
Lesson 2 - Refrigeration System Accessories
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
Lesson 3 - Desiccants and Driers
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.
Lesson 4 - Defrosting Methods
Objectives: Identify various defrosting
methods. Describe the basic operation of each method. Explain the advantages and disadvantages of each method.
Lesson 5 - Refrigeration System Controls
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.
Lesson 6 - Refrigeration System
Piping (Part 1)
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.
Lesson 7 - Refrigeration System Piping (Part 2)
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.
Lesson 8 - Retrofits and Disposal Requirements
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.”
Lesson 9 -
Compressor Replacement and System Evacuation
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.
Lesson 10 – Motors
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.
Lesson 11 - Electric Motors in Refrigeration Systems
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.
Lesson 12 – Capacitors
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.
Lesson 13 - Motor 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.
Lesson 14 - Motor Protectors
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.
Lesson 15 - Low-Voltage Thermostats
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.
Lesson 16 - Relays, Contactors,
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.
Lesson 17 - Test Equipment (Part 1)
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.
Lesson 18 - Test Equipment (Part 2)
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.
Lesson 19 - Troubleshooting (Part 1)
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.
Lesson 20 - Troubleshooting (Part 2)
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.
Lesson 21 - Troubleshooting (Part 3)
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.
Lesson 22 - Using Pressure and Enthalpy Diagrams (Part 1)
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
Lesson 23 - Using Pressure and Enthalpy
Diagrams (Part 2)
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.
Lesson 24 - Moisture in Air
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.
Lesson 25 - Calculating Cooling Loads
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.
Lesson 26 – Psychrometrics
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.
Lesson 27 - Heat Transfer (Part 1)
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.
Lesson 28 - Heat Transfer (Part 2)
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.
Lesson 29 - Estimating the Heat Load (Part 1)
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
Lesson 30 - Estimating the Heat Load
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.
Lesson 31 - Room Air Conditioners
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.
Lesson 32 - Types of Air Conditioning Systems
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.
Lesson 33 - Residential Air Conditioning
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.
Lesson 34 - Humidification (Part 1)
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.
Lesson 35 - Humidification (Part 2)
Objectives: Add moisture to air by various methods. Install
a humidifier properly. Control the humidity level properly.
Lesson 36 - Review of Safety and Codes
Objectives: Adhere to personal safety practices and
proper equipment safety practices. Comply with federal, state, and local safety codes and regulations.