1. When transporting a refrigerator, never lay it on its side or back because the compressor oil leaves the compressor. Then when in place and turned on, the compressor operates without lubrication, and it ends up having to be replaced. If for any reason it must be laid down for five minutes or longer, be sure it is in an upright position for a minimum of twelve hours before being turned on. This will allow sufficient time for the oil to return to the compressor crankcase.
2. Electrical power supply should provide enough voltage to start the compressor motor. For residential units, 115 volts ± 10% is the allowable fluctuation limit to start the motor. In other words, the voltage at the wall receptacle must be at least 108 volts. Otherwise, it will not be able to start the compressor motor. A voltmeter is needed to check the voltage. (Refer to “Testing the Supply Voltage” and see fig. 34.)
3. Sufficient ventilation is important where the refrigeration unit is installed. In the case of units that have a fan-cooled condenser, be sure nothing is blocking air circulation at the bottom and in the front of the unit. For units with their condenser in the back, a wall clearance of at least two and a half inches is required for proper air circulation. Make certain that adequate clearance is provided on top and bottom as well as all sides (see fig. 75).
4. Refrigeration units should be carefully leveled at the time of installation. This is probably the only time the level is checked. Most units now have built-in leveling “feet” that screw in or out of the base to level each corner. Also, rollers (or small dollies) are available if the unit is to be moved around. Small shims of wood or other material may be placed under the “feet” of the unit to be leveled. It is important to do this adjustment with a spirit level such as the ones carpenters use. Small metal ones (three or four inches long) are available and can be carried easily in a toolbox.
5. Since hermetic compressors used in residential refrigerators and freezers do not produce sufficient starting torque to overcome a high head pressure, if the unit is stopped and immediately restarted, it will not resume running until the head pressure in the system drops (by equalization of gas pressure through the capillary tube). This delay in starting does not mean there is something wrong. Wait for a few minutes until the head pressure drops low enough for the compressor to overcome it, then the unit will resume running.
6. Most refrigeration unit noises are caused by vibration, tubes touching one another or some object, loose ducts or air baffles, and fan motors. Vibration is caused mainly by a unit that is not level, uneven flooring or an out-of-balance fan blade. These noises can be eliminated by (a) locating the source of the noise, (b) placing rubber blocks between tubing, or carefully bending the tubing out of the way, (c) tightening the screws on loose ducts or air baffles and/or, (d) replacing the fan blade if it is out of balance.