Electricity plays an essential role in how your home operates. Whether watching TV, powering heating and cooling systems, or charging a cell phone, we rely on our home’s electrical system to provide us with power when and where we need it.
By understanding the basics of how electricity is distributed around your home, you can keep this important system properly maintained and in safe working condition:
Electricity enters your home through a service head from a series of outdoor power lines or an underground connection. A typical service head consists of two 120-volt wires and one neutral wire that deliver power to lights and appliances around the home.
The 120-volt circuits use one phase of the electrical service to power standard home appliances. However, certain larger appliances such as water heaters, electric rangers, or clothes dryers require a 240-volt circuit, which is created using both 120-volt wires and the neutral wire.
The electric meter is mounted outdoors where electricity enters your home. This device is used to measure the amount of electricity that is consumed in your home. The meter is monitored by your electric utility company and is protected by law—tampering with it is both extremely dangerous and illegal.
The electrical service panel is the central distribution point for delivering electricity to switches, outlets, and appliances throughout the house. Located near the electric meter, the service panel is equipped with breakers or fuses that shut off power to the circuits if an electrical system failure occurs.
Grounding is the method used to connect an electrical system to the earth with a wire. Grounding adds critical protection against electric shock and electrocution by using a grounding rod to provide a third path for conducting electricity in the event of a short circuit or an overload. Grounding will help protect the person working on the system, the system itself, and any appliances and equipment that are connected to the system.
Watch the Home Electrical System Safety Video (or Seguridad del sistema eléctrico de la casa) for a visual introduction to your home electrical system. You can also visit the Virtual Home for an interactive tour of a basic electrical system and the electrical devices commonly found in modern homes.