Why is abnormally low suction pressure undesirable?

Abnormally low suction pressure is primarily undesirable because it can lead to overheating of the motor in a hermetic compressor. When the suction pressure is too low, the compressor has to work harder to compress the refrigerant, which increases the load on the motor. This extra workload can cause the motor to operate outside of its optimal conditions, resulting in an increase in temperature. If the motor overheats, it can lead to premature failure, reduced efficiency, and in some cases, complete breakdown of the compressor system.

Additionally, it's important to understand the context around the other potential issues linked to low suction pressure. Low suction pressure can indeed impact cooling efficiency, result in freezing of the evaporator coil, and even contribute to refrigerant leaks but the direct and immediate risk to the compressor motor is a critical concern. The operational reliability of hermetic compressors is crucial, and maintaining appropriate suction pressure helps to ensure a balance between effective cooling and motor longevity.