The recommendation for outlet usage for refrigerators is based on manufacturer guidelines, as well as electrical codes. To avoid problems, it's advisable to follow any rules set by codes or as specified in the owner's manual. Otherwise, the refrigerators may not operate correctly; incorrect use may pose a fire or other safety hazard.
Refrigerator manufacturers recommend plugging the power cord into a separate, dedicated-circuit outlet. The manufacturer also usually specifies a certain voltage the appliance requires. Not using the proper amount of electrical power can affect the refrigerator's operation adversely.
City electrical codes may have a regulation governing appliance use; check with your city's zoning office. The code may state refrigerators require a separate outlet, equipped with ground-fault-circuit-interrupter protection. Because refrigerator outlets are within 6 feet of a water source, such as a faucet, GFCI protection is necessary to prevent electrical shock in the event the outlet comes in contact with water.
The refrigerators, when plugged into one outlet, must compete for their share of the electrical current. If the refrigerators, either separately or jointly, require more current than the circuit can provide, the wiring may overheat. The circuit breaker, when working properly, should shut off the outlet to prevent the wiring from operating in its heated state. But over time, when the wire is repeatedly overheated, the wire may become damaged or cause a fire.
Never use an extension cord with a refrigerator; it prevents the refrigerator from receiving the proper amount of power. Always follow the refrigerator manufacturer's guidelines for power use. If the electrical outlet connected to a refrigerator repeatedly shuts down and requires resetting through the circuit breaker, consult with a qualified electrician. The electrician can check the wiring and ensure the outlet has enough current to properly support the refrigerator's electrical needs.