Refrigerators, like other household appliances, contain a single electrical cord that supplies power to the appliance from your home's electrical system. Cord specifications may vary by manufacturer and model, but most refrigerators use similar appliance cords and plugs. The wall receptacle your fridge cord plugs into also is standard but has some specific requirements for optimal safety and operating performance.
Electrical Cord and Plug
Refrigerators run on standard 110/120-V (volt) electrical circuits and are fitted with cords with standard 3-prong grounded plugs. A grounded plug includes a third blade, or prong, that is round and serves as the electrical ground for the appliance. Never remove the ground prong because it is a safety feature that protects the appliance and your home in the event of an electrical short. Also, never use a plug adapter that allows you to plug a 3-prong plug into a non-grounded receptacle. These adapters do not provide a reliable ground path even when the electrical box is grounded.
Kitchens with up-to-date wiring include a receptacle (wall outlet) for the refrigerator that's on it own circuit, known as a dedicated circuit. This is to prevent other appliances or devices from drawing power from the same circuit, ensuring that the fridge has sufficient power to work properly and to protect against overloading the circuit. The outlet on this dedicated circuit is likely to be a standard duplex receptacle, so it's possible to plug something into the unused half of the receptacle; however, this is not recommended, as it defeats the purpose of a dedicated circuit. Many refrigerators can be powered by 15-A (amp) circuits, but current best practices favor a 20-A circuit for these constantly running appliances, and some models must be powered by 20-A circuits.
The receptacle on a dedicated fridge circuit must be the same amperage as the circuit wiring -- either 15-A or 20-A. A standard grounded receptacle is recommended for this appliance due to the frequent spikes in power draw caused by the fridge compressor starting up. For this reason, GFCI receptacles typically are not used for refrigerators, as power spikes can lead to nuisance tripping of these receptacles.
Extension Cord Warning
Your refrigerator's owners manual almost certainly includes a warning not to power the appliance with an extension cord, and this is good advice in any case. Plug-in appliances are designed (and warranted) for use only with the manufacturer-supplied power cord. Undersized extension cords may fail to provide sufficient power to the refrigerator and can overheat, posing a significant fire hazard. Long extension cords also can provide insufficient power and are susceptible to damage if exposed or coiled up under or around the refrigerator.