Electrical Fundamentals for HVAC-R
The electrical side of refrigeration and air conditioning, followed through a first-year apprentice at an HVAC-R contractor in Kitchener: electrical safety, lockout and approach boundaries under CSA Z462 and Ontario's rules; voltage, current, resistance, power and Ohm's law; series, parallel and control circuits and voltage drop; single-phase and three-phase supplies, including 347/600-volt systems; meters, measurement categories and insulation testing; 24-volt control transformers; switches, relays, contactors and overloads; single-phase motors, capacitors and start relays; three-phase motors, ECMs and variable-frequency drives; ladder and wiring diagrams; thermostats and the control sequences of air conditioners, furnaces and heat pumps; and systematic electrical troubleshooting.
RAC-130 12 lessons · 4 h 15 min ▶ Video lessons coming soon
Offered by HSM University · Refrigeration and Air Conditioning
This is the Canadian version of this course. See the American version.
What you'll learn
- Explain how current harms the body and how arc flash occurs, and apply CSA Z462, Ontario's OHS rules, lockout and live-dead-live testing to HVAC-R electrical work
- Define voltage, current, resistance, power and energy, and use Ohm's law and the power formulas to check heaters, connections and equipment ratings
- Analyse series, parallel and combination circuits, explain why controls are wired in series and loads in parallel, and calculate voltage drop in conductors
- Describe AC waveforms, reactance, impedance and power factor, and identify single-phase and three-phase supply systems, including 120/240, 120/208 and 347/600 volts
- Select meters by measurement category and make safe, accurate measurements of voltage, current, resistance, capacitance and insulation resistance
- Explain how transformers work, size and test 24-volt Class 2 control transformers, and trace the low-voltage circuit from thermostat to equipment
- Describe switches, pressure and temperature controls, relays, contactors and overloads, distinguish overload from short-circuit protection, and test each device
- Explain how single-phase motors start and run, identify compressor terminals, and select and test run and start capacitors and start relays
- Describe three-phase motors, ECMs and variable-frequency drives, recognize single-phasing, apply the affinity laws, and work safely with stored energy in drives
- Read pictorial, connection and ladder diagrams, interpret their symbols, and trace a sequence of operation through a ladder
- Explain thermostat types and terminals and the control sequences of air conditioners, furnaces and heat pumps, including reversing valve control, auxiliary heat and defrost
- Apply a systematic method to troubleshoot electrical faults, find root causes and verify repairs on residential and commercial HVAC-R equipment
Course content
12 lessons · 4 h 15 min total · final exam
- 1 Electrical safety for HVAC-R work 26 min · quiz
- 2 Electrical quantities, Ohm's law and power 20 min · quiz
- 3 Series, parallel and control circuits 20 min · quiz
- 4 AC power: single-phase and three-phase supplies 20 min · quiz
- 5 Meters and safe measurement 22 min · quiz
- 6 Transformers and 24-volt control circuits 20 min · quiz
- 7 Switches, relays, contactors and overloads 22 min · quiz
- 8 Single-phase motors and capacitors 22 min · quiz
- 9 Three-phase motors, ECMs and variable-frequency drives 20 min · quiz
- 10 Reading wiring diagrams 20 min · quiz
- 11 Thermostats and basic control sequences 21 min · quiz
- 12 Systematic electrical troubleshooting 22 min · quiz
- E Final exam 20 questions
Requirements
Recommended background. You can start any course at any time.
Description
The electrical side of refrigeration and air conditioning, followed through a first-year apprentice at an HVAC-R contractor in Kitchener: electrical safety, lockout and approach boundaries under CSA Z462 and Ontario's rules; voltage, current, resistance, power and Ohm's law; series, parallel and control circuits and voltage drop; single-phase and three-phase supplies, including 347/600-volt systems; meters, measurement categories and insulation testing; 24-volt control transformers; switches, relays, contactors and overloads; single-phase motors, capacitors and start relays; three-phase motors, ECMs and variable-frequency drives; ladder and wiring diagrams; thermostats and the control sequences of air conditioners, furnaces and heat pumps; and systematic electrical troubleshooting.