Chapter 25 Installation and Troubleshooting of Domestic Refrigerators and Freezers 643 Copyright Goodheart-Willcox Co., Inc. 8 sure the refrigerator runs before moving it into its final position. After a few hours of operation, check the ther- mometer in the fresh food (refrigerator) compartment. Adjust the temperature control setting to the custom- er’s requirements. 25.2 Diagnosing Symptoms Refrigerators, like all machines, eventually wear out or suffer malfunctions. Just as a doctor analyzes a patient’s symptoms to determine what is wrong, an HVACR technician observes the symptoms of the refrigeration system’s malfunction and performs a test to determine what is wrong with the system. It is extremely important to work methodically when trou- bleshooting a system. 25.2.1 Diagnosing a No-Start Condition If a refrigerator does not start, make sure that the electrical supply circuit is in good condition and that the proper voltage is being delivered to the unit. Open and close the doors to make sure that the interior lights are functioning properly. If the interior lights fail to turn on and off as the door opens and closes, look for problems in the electrical supply circuit. Check any cir- cuit breaker or fuse in the circuit. If the lights turn on and off as expected, the refrigerator is being supplied with power, and the problem is likely in the motor control circuits or the compressor’s motor itself. The troubleshooting pro- cess should begin with a visual inspection to check for obvious problems. After the visual inspection, the external electrical circuits should be checked for prob- lems. Look for any loose connections, broken wires, or other problems with the electrical components. Finally, the system should be checked for mechanical trouble that prevents its startup. The troubleshooting process described in the sections that follow can be applied to a refrigerator that will not start or one that is performing poorly. Pro Tip Restarting a Capillary Tube SystemmsteyS If a refrigerator-freezer equipped with capillary tube metering device is stopped and then started imme--e diately, it may fail to operate. This is not necessarily a malfunction. The motor in this type of refrigerator has insufficient starting torque to overcome high head pres--s sure. Disconnect the refrigerator for a few minutes to allow the high-side and low-side pressures to balance. Then, try starting the system.. Restarting a Capillar y Tube If a refrigerator-freezer equipped with capillary tube metering device is stopped and then started imm diatel y, it ma y fail to operate. This is not necessaril y a malfunction. The motor in this type of refrigerator has insufficient starting torque to overcome high head pre sure. Disconnect the refrigerator for a few minutes to all ow t h e high-side an d low-side pressures to balance. Then, try starting the system 25.2.2 Diagnosing Poor Performance The first step in diagnosing a faulty system is to visually inspect the system, looking for any obvi- ous problems. A very helpful device for inspecting a refrigerator is an inspection mirror, which is a small adjustable mirror mounted on a long extension. Most inspection mirrors have a telescoping handle. The mir- ror pivots and can be used to check such things as fan alignment, motor condition, cleanliness of the con- denser, the condition of the evaporator, and any other hard-to-reach places, Figure 25-4. Caution Inspection Mirrors When inserting an inspection mirror into a recessed or obstructed area, be aware that the area may contain moving parts that are hidden from view. Always avoid touching moving parts with an inspection mirror.. If a problem is detected during the visual inspection, determine whether that problem could result in the symp- toms you are investigating. Also, determine whether the problem you detected during the inspection could actu- ally be a symptom of an even larger problem. Inspection Mirrors When insertin g an inspection mirror into a recessed or obstructed area, be aware that the area may contain moving parts that are hidden from view. Always avoid touchin g movin g parts with an inspection mirror Ritchie Engineering Co., Inc. – YELLOW JACKET Products Division Figure 25-4. An inspection mirror is often needed to see into hard-to-reach places.