What voltage is most commonly used to power the outdoor unit in a residential system?

The voltage most commonly used to power the outdoor unit in a residential heat pump system is indeed 240V Single Phase. This voltage level is favored in residential applications due to its efficiency in powering the motors and compressors typically found in heat pumps.

In many residential settings, electrical systems are designed around 120V for standard outlets and lighting; however, many major appliances, including heat pumps, require more power to operate effectively. The 240V supply allows for lower current draw, which can reduce wire size and improve energy efficiency.

Additionally, using 240V ensures that the system can handle the starting current required by the compressor without overwhelming the circuit, which is especially important during peak load conditions. This voltage is also widely available in homes, making it the most practical choice for residential heat pump installations.

In contrast, the other voltage options, such as 120V Single Phase or higher voltages like 480V Single Phase and 240V Three Phase, are less common in typical residential installations. The lower voltage might not provide sufficient power for the operation of larger units, while higher voltages are typically reserved for commercial applications or specialized industrial equipment.