Question 59Refrigeration & AC - 1st Asst/Chief

The correct answer is D) all of the above. Unusual noise from a refrigeration compressor can be caused by a variety of conditions, including worn bearings and piston pins, too much oil in circulation, and slugging due to flooding back. These issues can each create abnormal noises that indicate potential problems with the compressor's operation. Diagnosing and addressing the root cause of the unusual noise is important to maintain the proper function and efficiency of the refrigeration system.