Compressor preheating is a protection mechanism used during first power-on (and after long power-off periods) to improve compressor reliability before allowing refrigeration startup. The preheating function warms the compressor oil and reduces refrigerant migration and oil dilution, which otherwise can lead to liquid refrigerant in the compressor crankcase. If the compressor starts when oil is diluted or when liquid refrigerant is present, it increases the risk of abnormal noise, poor lubrication, high mechanical stress, and even liquid strike, which can damage the compressor and shorten service life. For data center cooling equipment, where continuous reliability is essential, the commissioning logic treats preheating as a required prerequisite for safe compressor operation. Therefore, O&M practice does not recommend bypassing or manually shutting down compressor preheating just to accelerate commissioning. The correct approach is to keep the unit energized and allow the preheating period to complete, then proceed with commissioning steps (fans, cooling system tests, alarms, and control verification) under proper protection conditions.