HVAC Excellence Electrical Certification Practice Exam 2026 - Free HVAC Practice Questions and Study Guide

In an HVAC system, the component specifically designed to start the compressor motor is the contactor. The contactor serves as an electrically controlled switch that connects and disconnects the power supply to the compressor motor, allowing it to start and run when needed.

When the thermostat demands cooling, a signal is sent to energize the contactor, closing the circuit and allowing electricity to flow to the compressor motor. This is essential for the operational control of the compressor, enabling it to function correctly and efficiently within the HVAC system.

While capacitors are also important in the context of motors, they are primarily used to provide an initial boost of energy for starting the motor and to improve the power factor during operation, rather than serving as the primary means of connecting or disconnecting power. Transformers are typically used to step voltage up or down and are not responsible for starting the compressor. Timers can be involved in various scheduling functions within the HVAC system but do not directly control the starting of the compressor motor.