Why is abnormally low suction pressure undesirable?

Abnormally low suction pressure is undesirable primarily because it can lead to the motor of a hermetic compressor overheating. When the suction pressure is low, the compressor struggles to draw in enough refrigerant vapor. This insufficient flow can result in the compressor operating in a less efficient state, causing it to work harder to compress the limited amount of refrigerant it is able to intake. As a result, the motor can become overheated due to the increased workload and insufficient cooling, potentially leading to compressor failure.

This phenomenon also contributes to other negative impacts on system performance, but the specific concern of motor overheating is critical, particularly for hermetic compressors, which are sealed units and more susceptible to damage if they run under adverse conditions.