Copyright Goodheart-Willcox Co., Inc. 666 Chapter Review Summary • To check a refrigerator-freezer for proper installation, begin by inspecting the unit for damage resulting from shipping or improper handling. Ensure that the unit is level and has adequate ventilation for its type of condenser. • Ice makers should be attached to a cold-water supply line and the water supply tubing should be long enough to allow the refrigerator to be moved for cleaning and servicing without disconnecting or damaging the tubing. • The refrigerator should be on a separate electrical circuit and properly grounded. • If a refrigerator fails to start, check the supplied power and then check for electrical problems. Finally, check for mechanical problems. • The troubleshooting process should begin with a visual inspection of the system. The next step after performing a visual inspection is determining possible causes of the symptoms. • Troubleshooting charts are useful tools for determining possible causes of common symptoms. Some common symptoms include ice on the evaporator, moisture in the cabinet insulation, unusual noises, unusual cycling times, and failure to cool. • Eliminate possible external causes for symptoms before assuming the problem is in an internal component. Use proper electrical troubleshooting techniques to make sure there are no problems with the power-in connections, thermostats, overload protection, relays, or capacitors. • A sweating or frosted suction line indicates that liquid refrigerant is getting into the suction line. Excessive frosting on the capillary tube or filter- drier and a warm evaporator indicate that not enough refrigerant is reaching the evaporator. • Service valves are usually not built into hermetic systems. However, valve adapters or piercing valves can be installed in the system to provide a technician with a means to connect gauges and service equipment to the system. • Excessively low low-side pressure can be caused by a restriction in the system or a lack of refrigerant. • Ice formation in the refrigerant circuit can cause a restriction and is an indication of excess moisture in the refrigerant. To correct this problem, thaw the ice blockage, recover and filter the refrigerant charge, and install a new filter-drier to remove the excess moisture. Pull a vacuum on the system and recharge it with the proper amount of refrigerant. • Wax buildup can clog a metering device. If a shortage of refrigerant in the evaporator is found to be caused by wax buildup instead of ice, replace the metering device and filter-drier and also replace the refrigerant oil with a high- quality low-wax oil. • Once you have diagnosed a system based on visual inspection and analysis of system performance, perform pinpoint tests to make sure the suspected component is faulty before replacing it. Internal system components that typically cause problems are compressors, filter- driers, metering devices, hot-gas defrost bypass valves, and electric defrost resistance heaters. Review Questions Answer the following questions using the information in this chapter. 1. Which of the following statements regarding shipping bolts is not true? A. If the compressor is spring mounted, the shipping bolts are usually removed after the unit is installed. B. If the compressor is mounted on synthetic grommets, the shipping bolts must be tightened after the unit is installed. C. The purpose of shipping bolts is to secure the compressor during shipping. D. All of the above. 2. Which of the following statements about installing refrigerators is not true? A. A refrigerator-freezer should only be placed in a room that is large enough to provide sufficient air to cool the condenser. B. A refrigerator-freezer should be positioned away from potential heat sources, such as ovens, radiators, and warm air registers. C. A refrigerator-freezer should be positioned in direct sunlight. D. Technicians can use a spirit level, wood shims, and levelers to install a refrigerator that is level. 3. Why should there be several large loops in the tubing connecting the water line to a refrigerator’s water line fitting? A. To prevent condensation from forming on the water line. B. To ensure an adequate pressure drop in the water supply. C. To allow the refrigerator to be moved without disconnecting the water connection. D. None of the above.