Exercises
Exercise involving 12 errors
The oil used for lubrication of refrigeration compressors is highly miscible with commonly used refrigerants.This strong affinity of the refrigeration oil for refrigerants causes many problems. It can cause mechanical faults (e.g. broken compressor valve reeds or compressor seizures), and electrical faults (e.g. motor "burnout"), as well as thermodynamic problems (e.g. lack of refrigeration capacity, excessive safety trip-outs etc.).
The aim of this chapter is to provide a response to the questions that most engineers will ask themselves about oil return...
EXERCISE : Try to find at least 12 of the fabrication or design errors that have been introduced into the schematic diagram of the system below. The installation is a direct expansion system with air-cooled condenser and a 3 capacity stage compressor (33, 66 and 100%).
(Solution : Refrepair Manual pages 261 to 268)
