What is the main purpose of the "Y" terminal in HVAC systems?

The "Y" terminal in HVAC systems is primarily responsible for energizing the cooling circuit. When the thermostat calls for cooling, it sends a signal to the "Y" terminal, which in turn activates the compressor and the outdoor condenser unit. This process enables the system to start cooling the home by circulating refrigerant and facilitating heat exchange. The "Y" terminal is integral in the control sequence for cooling operation, ensuring that when cooling is needed, the necessary components are engaged to provide comfort to the space.

Understanding this function helps highlight the importance of the "Y" terminal in maintaining efficient cooling performance in residential air conditioning systems.