Compressors are preferred reliability grounds units primarily designed for the smaller ranges of temperatures required in Air conditioning or cooling. In small equipment, where the cost is the most important factor, and the installation location is desirable to minimize, for example, sealed engine and compressor combination (Fig. 3.3), there are no rotating seals, separating the motor and compressor, and the internal components will not be available for maintenance, the building of the plant of welded.
In these compressors that are available for the low power of the drive and motor are sealed in a compact welded body. The refrigerant and lubricating oils contained in this package. Almost all small motor-compressor of the pairs used in domestic refrigerators, freezers and air conditioners hermetic type. Internal view of hermetic type refrigeration compressor is shown in Fig. 3.3. The capabilities of these compressors are identified with their motor capacities.
For example, the productivity of the compressor is 1/12 HP 30 BG in domestic refrigerators. Their revolutions per minute, or 1450 or 2800 rpm Hermetic compressors can work for a long time in the small capacity of the refrigeration systems without any maintenance requirements and without any gas leaks, but they are sensitive to electric voltage fluctuations, which can make the copper coils ignition engine. The cost of these compressors is very low. In addition, Fig. 3.4 shows two condensing units with hermetic type refrigeration compressor.
Compressors 