xix 16.4 Motor Protection Devices ....................376 16.5 Direct Digital Controls (DDC) ..............380 CHAPTER 17 Servicing Electric Motors and Controls .............................................390 17.1 Electrical Test Equipment ....................392 17.2 Troubleshooting Electric Motors ..........400 17.3 Servicing Hermetic Compressor Motors ................................................404 17.4 Servicing Fan Motors ..........................407 17.5 Servicing External Motors ...................409 17.6 Servicing Motor Control Systems ........414 Section 7 Refrigeration System Components CHAPTER 18 Compressors .....................................422 18.1 Compressor Drive Configurations ......424 18.2 Types of Compressors ........................427 18.3 General Compressor Components and Systems ......................................446 CHAPTER 19 Compressor Safety Components ....456 19.1 Compressor Operating Conditions .....458 19.2 Compressor Protection Devices .........458 19.3 Oil Control Systems ............................462 19.4 Vibration Absorbers ............................466 19.5 Crankcase Heaters .............................467 CHAPTER 20 Metering Devices ............................470 20.1 Metering Device Basics ......................472 20.2 Capillary Tubes ...................................472 20.3 Metering Orifices ................................476 20.4 Thermostatic Expansion Valves (TXVs) ................................................477 20.5 Automatic Expansion Valves (AXVs) ................................................493 20.6 Electronic Expansion Valves (EEVs) ................................................496 20.7 Float-Operated Refrigerant Controls ... 501 CHAPTER 21 Heat Exchangers ..............................510 21.1 Evaporators .........................................512 21.2 Condensers ........................................535 21.3 Head Pressure Control ........................544 21.4 Other Heat Exchangers ......................547 CHAPTER 22 Refrigerant Flow Components .....558 22.1 Refrigerant Loop Components ...........560 22.2 Storage and Filtration Components .......................................560 22.3 Refrigerant Flow Valves ......................565 22.4 Pressure-Regulating Valves ................575 22.5 Head Pressure Controls Valves ..........584 Section 8 Domestic Refrigerators and Freezers CHAPTER 23 Overview of Domestic Refrigerators and Freezers ............596 23.1 Domestic Refrigeration .......................598 23.2 Refrigerators and Freezers .................599 23.3 Innovative Technologies .....................605 CHAPTER 24 Systems and Components of Domestic Refrigerators and Freezers .....................................................610 24.1 Basic Components of Refrigerators and Freezers ......................................612 24.2 Specialized Systems ..........................620 CHAPTER 25 Installation and Troubleshooting of Domestic Refrigerators and Freezers .............................................638 25.1 Checking for Proper Installation..........640 25.2 Diagnosing Symptoms .......................643 25.3 Checking External Circuits .................650 25.4 Diagnosing Internal Troubles ..............654