Can You Add an Electrical Socket for a Dryer In a Laundry Closet With Only One Plug?

Dryer Sockets

• Dryers typically use both 120- and 240-volt electricity; the circuitry and the motor that rotates the drum operate on 120 volts, and the heating elements that make the air in the dryer hot operate on 240 volts. This is accomplished by delivering the electricity to the socket via a special four-core wire. Along with the usual green or bare ground wire and the white neutral wire, there are two hot wires; one is red and one is black. The circuitry and motor draw power from only one of the hot wires, while the heating element draws power from both.

Power Demand

• A dryer socket must be supplied by 10-gauge wire or larger, while most regular plugs -- including those in laundry closets -- use only 12-gauge. This smaller wire will overheat inside the walls and at the screws in the rear of the socket if used to operate a 20-amp appliance such as a dryer. Overheating wires and sockets are extremely dangerous; they can cause fires to start and can arc electricity to people inserting or withdrawing a plug.

Circuit Protection

• Dryers are typically manufactured to use approximately 4,500 watts, meaning they need a 30-amp fuse or circuit breaker. The breaker should be “double-pole,” meaning it conveys power from both the bus bars in the panel. Some dryers need a larger circuit protector; this information is provided in the delivery and installation manual and usually repeated on a sticker somewhere on the rear of the machine.

  The likelihood is remote that the fuse or breaker protecting the pre-existing plug in the laundry closet is 20-amp or greater, and simply to uprate the protector is strongly discouraged. The wire gauge used to make the circuit is probably sized to take safely only the current that can pass through the existing protector. The pre-existing plug is almost certainly supplied by a single-pole breaker also, meaning it does not convey 240 volts.

Code

• Municipal safety codes usually mandate that dryers be supplied by their own dedicated circuit. To effect changes to wiring put in to code by professional installers is foolish at best and both dangerous and illegal at worst.