120V vs 240V
US homes receive two 120-volt legs from the utility. Standard outlets use one leg (120V); dryers, ranges, EV chargers and AC equipment use both legs together (240V).
Every breaker in your panel connects to one or both of two energized bus bars. A single-pole breaker grabs one bar and feeds 120-volt circuits: lights, general outlets, small appliances. A double-pole breaker bridges both bars and delivers 240 volts for loads that need real power. Same electricity, twice the pressure, and at a given wattage half the current, which is why heavy equipment is built for 240.
The practical question homeowners hit: "can I plug this in, or do I need a new circuit?" Welders, EV chargers, hot tubs, RV hookups and most shop tools above 1,800 watts want a dedicated 240-volt circuit, which is an everyday job for an electrician but never a DIY adapter situation.
Talking to a contractor about this?
Run the project past a licensed electrical pro first. Calls are answered around the clock and routed to a pro serving your area.
- Amp (Ampere) : The unit of electrical current: how much electricity is flowing through a wire at a given moment.
- Watt & Kilowatt : The unit of electrical power: volts multiplied by amps.
- Kilowatt-Hour (kWh) : The unit your utility bills you for: one kilowatt of power used for one hour.
- Voltage Drop : The loss of voltage along a wire run, caused by the resistance of the wire itself.