HVAC
What are the 3 main colors of wires
Black, white, and green wires
What is the purpose of a thermostat in a furnace
Controls temperature
What is subcooling in refrigeration
Cooling refrigerant below condensing temperature
What can happen if a refrigerant charge is too low
Poor cooling and frozen coils
What fuel sources can a furnace use
Gas, propane, oil, or electricity
What safety device shuts off the furnace if it overheats
High-limit switch
What can cause a furnace to short circuit
Bad wiring or loose connections
What is the purpose of the flame sensor
Detects burner flame
What is ohms law
Voltage = Current × Resistance
What is amperage
V=IR
What does a fuse do in an electrical system
Electrical current
What is the most common type of refrigerant
Protects circuits from too much current
What is the most common type of refrigerant
R-410A
What are signs of an overcharged refrigerant system
High pressure and poor cooling
How does a TXV regulate refrigerant based on the load conditions
Adjusts refrigerant flow
In a split HVAC system how does static pressure affect airflow
Adjusts refrigerant flow
What is the role of blower motor capacitor
Reduces airflow
How can you diagnose a bad capacitor with multimeter
Helps blower motor start and run
How does the reversing value function in a heat pump system
Test capacitance with a multimeter
What is the purpose for a pressure switch in a furnace
Reverses refrigerant flow
How does duct design influence CFM delivery
Ensures safe airflow and venting
How do load calculations determine proper HVAC system sizing
Controls airflow delivery
How does humidity control interact with cooling performance
Sizes HVAC systems correctly
What are the mechanic in a motor1
Improves comfort and efficiency
What is the function of an inducer motor in a gas furnace
Rotor, stator, bearings, windings