I'm an expert in electrical engineering with a focus on residential electrical systems. When it comes to the voltage in a house, it's important to understand that there are several factors that can affect this, including the local electrical code, the age of the house, and the specific requirements of the household appliances.

In the United States, the standard voltage for residential homes is typically 120 volts for outlets and lighting circuits, and 240 volts for certain high-power appliances such as electric dryers, ovens, and air conditioners. This is part of the National Electrical Code (NEC), which sets the standards for safe electrical installations.

The reference to "two 110 volt wires" in the provided information is likely a bit of a misunderstanding. What is actually meant is that there are two hot wires, each carrying 120 volts, and one neutral wire. The two hot wires are typically referred to as the "phase" wires, and they are used to provide power to different circuits within the house. When appliances are connected between one of the hot wires and the neutral wire, they operate at 120 volts.

However, when appliances are connected between the two hot wires, they operate at 240 volts. This is how the 220 volt service mentioned in the reference is achieved. The slight discrepancy between 220 volts and 240 volts is due to the voltage drop that occurs over the distance from the power source to the appliance, which is a standard consideration in electrical engineering.

It's also important to note that the voltage can vary slightly from house to house due to factors such as the distance from the power source, the type of wiring used, and the load on the electrical system. Additionally, some older homes may still have 110 volts for certain circuits, but this is becoming increasingly rare as the NEC has been updated to standardize on 120 volts for safety and efficiency reasons.

In summary, while the standard voltage for outlets and lighting circuits in a house is 120 volts, certain high-power appliances require 240 volts, which is achieved by connecting them between the two hot wires. It's crucial to adhere to the NEC and local electrical codes when installing and using electrical systems to ensure safety and compliance.

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Most houses today have two 110 volt wires and one neutral wire running into the house from the local distribution system. These wires can run underground or above ground. If there are two 110 volt wires running to the house, then the house has 220 volt service and appliances, such as dryers and air conditioners.read more >>