Let’s start with a definition of terms so we’re all on the same page. A range, sometimes called a stove, is a single appliance containing an oven and a cooktop. There are freestanding ranges, which typically plug into a receptacle, and there are drop-in ranges, which typically are hard-wired (not plugged in). Plug-in electric ranges are supplied by 120/240-volt receptacles.They need 120-volt service for timers, sensors, buzzers, and 240-volt service for the heating elements and burners.
Most range circuits are 50-amp, but this can vary depending on the range requirements. What can’t vary is the receptacle type: since 1996, the National Electrical Code (NEC) has required 4-conductor circuits for electric ranges, ovens, and cooktops. This means the receptacle has four slots to accept a 4-prong cord plug. It’s a violation of code to install a new receptacle that is made for the old-style 3-prong cords.
3-Prong vs. 4-Prong
Ranges and clothes dryers have a similar story. Prior to 1996 (it was actually closer to 2000 when the new rules were widely adopted), electric ranges and dryers were wired with three conductors: two “hots” and one neutral. The appliance body, or case, was grounded through the neutral so that the dryer cord and receptacle did not have a separate ground. After the change, appliances began to be sold with the case ground separated from the neutral. This configuration calls for a 4-conductor power cord that has a separate ground wire that connects to the ground screw on the appliance. The old system worked just fine, but the new system is safer.
While we’re on the subject of 3-prong and 4-prong cords, you should know that the NEC allows the use of existing 3-slot receptacles that work with the old-style 3-prong cords. The 4-conductor rule applies only to installation of new receptacles. If you’re reading this because you have an old 3-slot receptacle but have bought a new range that is configured for a 4-prong cord, you can install a 3-prong cord instead of replacing your old receptacle. However, you must configure the range wiring so the case ground is tied to the neutral terminal. Many ranges are sold with a metal bonding strip or wire for doing just that. Consult the owner’s manual or the range manufacturer for instructions.
Amperage Requirements and Recommendations
The NEC has different rules for different types of ranges. Drop-in ranges are usually hard-wired, and the circuit conductors must be sized for the wattage of the nameplate rating of the appliance. Circuits for plug-in freestanding ranges can actually be lower than the nameplate rating. If the rating is 12,000 watts or less, the circuit can be designed for 8,000 watts. This means you could supply your new receptacle with 8 AWG cable and a 40-amp breaker, rather than 6 AWG and a 50-amp breaker. The NEC makes this allowance because the nameplate rating is based on the oven and burners all being on HIGH at the same time, which doesn’t happen very often. But if you’ve ever hosted a big dinner, you know that firing everything at once, and for long periods, isn’t unrealistic. Therefore, it’s a common best practice to design a range circuit with a 50-amp breaker and 6 AWG conductors.
Range Receptacle Installation
An electric range receptacle can be a surface-mount box or a flush-mount receptacle installed in a recessed box. Either type of box must be sized for the conductors you’re using. The standard 50-amp circuit calls for 6-3 NM-B (w/ground) copper cable and a 50-amp, 4-slot range receptacle.
The location of the receptacle usually is determined by the appliance. Receptacles for freestanding ranges typically are accessible through an opening in the back of the range. When it’s time to plug in the range, you pull out and completely remove the drawer below the oven, then reach through the cavity from the front to get to the receptacle. Therefore, it’s best to mount the receptacle based on the range manufacturer’s specifications. Typically this is on the back wall (or sometimes the floor) behind the range, several inches above the floor and somewhat off-center in the cabinet space for the range.