It’s easy to get confused when we talk about the voltage range that a home electrical system supplies to our devices. For a long time, most people called the power from your home outlet “110 volts.” Similarly, “220 volts” was used for larger household appliances like electric ranges and clothes dryers. These designations for home AC power are actually out-of-date. They don’t accurately describe the voltage range that comes into your home from the electric utility. So, why the confusion?

These days, almost every residential customer can get 120 volts from their wall outlet. However, power is typically delivered into your home at a nominal voltage of 240 volts. Inside the transformer on the utility pole, the power is divided into a split phase system, with each line having a nominal voltage of 120 volts. Nominal voltage is the voltage that the line is designed for; however, in the real-world, the tolerance for voltage fluctuations is −5% to +5%. This leads to an actual voltage range of anywhere from 114V to 126V from your outlet and a voltage range of 228V to 252V for your full-phase appliances. Now, you might look at these voltage ranges and think that a difference that large could potentially pose a hazard to you or your electric devices. However, I can assure you that this is completely normal and is taken into consideration when the circuits are designed.

We talked briefly about the 240 volts that is supplied to your home from the power company. At the transformer, the single phase power from the utility company is split into 3 wires: 2 line wires and a ground. This is known as a single-phase three-wire or split-phase system. Normally, your lamps and other 120V devices are connected between one line wire and the grounded center, while electric stoves, dryers, and other appliances are connected to both line wires and the ground. This way, each half can balance the other when electrical loads increase. Our Quick 220® voltage converter combines these halves and produces a convenient outlet with a voltage range of 228V to 252V without the need to call an expensive electrical contractor.

I hope you’ve learned a bit today about the North American electrical grid and how the Quick 220® voltage converters work. It is always our mission to not only make electric power more convenient, but also to educate.