Which compressor is commonly started first in a two-stage system?

In a two-stage compression system, the low stage compressor is typically started first. This is important because the low stage compressor is responsible for initially increasing the pressure of the refrigerant before it enters the high stage compressor. The sequence ensures that the gas is adequately compressed to a pressure that the high stage compressor can efficiently handle. Starting the high stage compressor without this pre-compression can lead to operational issues, as it may not have the appropriate conditions to effectively compress the refrigerant further.

Starting both compressors at the same time or starting the high stage first can result in system inefficiencies and can potentially cause damage or excess strain to the equipment, as the high stage compressor may not be fed with gas at the correct pressure. Therefore, the correct and most efficient operation of a two-stage system necessitates that the low stage compressor is the first to be activated.