Heating, Ventilation, and Air Conditioning (HVAC ) Electrical Practice Test

What is the typical service voltage supplied to residential homes by utility companies?

1. 120V, single phase

2. 240V, single phase, three wire

3. 480V, three phase

4. 220V, three wire

The correct answer is: 240V, single phase, three wire

The typical service voltage supplied to residential homes by utility companies in many regions is 240V, single phase, three wire. This setup allows for both 120V and 240V circuits within the home. Most household appliances, like dryers and ovens, require the 240V connections, while general lighting and smaller appliances operate on the 120V supply. In this configuration, the three wires consist of two hot wires and one neutral wire. The two hot wires each provide 120V with respect to the neutral, so when used together, they can provide the 240V needed for larger appliances. This versatility in voltage levels makes it ideal for a wide array of household devices, ensuring that homes can effectively meet various electrical demands. In contrast, other options either refer to voltages not typically found in residential settings (like the three-phase system or voltages higher than standard residential supply) or to configurations that do not provide the necessary flexibility for both high and low voltage usage within homes.