As you walk through your home, you’ll see many electrical outlets. But not all of them are the same; in fact, some may be better suited for some purposes than others. Outlets come in many forms with different specifications. A 250-volt outlet has a higher capacity than both the 120-volt and 15-amp outlet used to power lights and electronics that need only 110 volts.
A 250-volt, 20-amp outlet is used for high-power appliances. It can have three or four prongs and requires a double-pole circuit breaker to be installed in the main electrical panel. A double-pole breaker takes up two slots on the panel and is fed by both bus bars. There are 250-volt outlets to accommodate even higher power needs, such as 30-amp and 50-amp outlets.
How a 250-Volt Outlet Works
An appliance connected to a 250-volt outlet essentially has its own dedicated circuit (it’s said to be “hard-wired” if connected directly to the circuit wires). No other devices are connected, as the large appliance connected to it has likely met the circuit’s capacity. Plugging additional items in would be a building code violation.
Smaller appliances need only one hot wire to operate. But in addition to the white neutral and bare copper ground wire, larger devices need two hot wires. The cable used must be appropriate for the amperage and be run from the breaker panel to the specific outlet box. Once the outlet is installed and wired to the panel, the appliance can be used.
Why It Is Needed
A 250-volt circuit is often used for air conditioners. The larger the unit, the more amps it will need; for example, 50 amps are sometimes required for large central AC units. A window unit may only need 20 amps. An air conditioner circuit is usually wired with nonmetallic cable, with a wire gauge appropriate for the amperage (20-amp circuits typically need 12-gauge wire, while 30-amp ones need a 10-gauge wire). Generally, circuit breakers can handle surges from AC startup, so are unlikely to trip.
Other applications in which a 250 v outlet may be used include:
- Power tools
- Air compressors
- Water heaters
- Electric stoves
- Large ovens
- Welding equipment
How to Wire a 250-Volt Outlet
Wiring a heavy-duty outlet can be tricky. The decision to do so often comes when you purchase an appliance. To determine how many amps you need, check the product’s instructions. Then you’ll need to purchase a breaker and cable with the appropriate amp rating; a 3-wire cable is needed for this type of application.
Then you need to:
- Run the cable from the panel to the outlet box where the plug will be installed.
- Remove about 6 inches of wiring jacket to separate the wires.
- Strip about ½ inch of insulation, so the copper wire is exposed.
- Connect the red and black wires to the terminal blocks labeled “hot” at the back of the outlet.
- Connect the white wire to the neutral black and copper ground wire to the ground block.
- Tighten the terminal screws on each to secure the wires.
- Screw the outlet to the outlet box.
Verify the power is off at the breaker panel and then slide the new breaker into an empty slot. Slide the black and red wires into the terminal blocks on the breaker and tighten the screws. Next, slip the white wire into the neutral bus bar, tighten the screw, and do the same with the bare copper wire, which attaches to the ground bus bar. Now you can turn the power on and start using the outlet for high-power appliances.
Schedule Help from Black Hills Home Services
When you need electrical panel work, it’s important to hire an electrician who has the experience, training, and tools needed to provide repairs/updates safely. Our wiring experts can help increase electrical capacity and ensure your home is up to code. Committed to your safety, we’re available 24/7 and offer maintenance plans plus flat-rate pricing. We also offer financing options. If you need a 250 v outlet installed, just call Black Hills at 888-579-5905.