Service Entrance

• The service entrance is the point where electricity enters your home from the power lines. If you look at your service entrance, you will see the "service entrance cap." The wires from the power lines run through your service entrance cap and through a conduit (a pipe) that leads to your panel box. The service entrance wires are high-voltage cables. Service entrance repairs and installations are always best left to a professional.
  
  

The Panel Box

• Your panel box distributes all the electricity in your home. It is divided into two sections. There is the section where your service entrance wires connect, and there is the circuit breaker section. Circuit breakers vary in size depending on the load that the circuit has to carry. A circuit with a washer and dryer on it would need a larger breaker than a circuit for lights and receptacles. Repairs inside the panel box are also best left to a professional.
  
  

Wiring

• There are strict electrical codes that regulate the types of wire used in electrical wiring systems. These codes regulate the necessary size, gauge or type of wire based on the load that the circuit has to carry. There are other factors that determine what type of wire can be used in electrical wiring systems. Different types of wire must be used in industrial or residential applications and indoor or outdoor applications. ROMEX® cable is generally used in indoor residential wiring applications. ROMEX® is an insulated cable containing three or four conductors, depending on the wiring application. ROMEX® cable includes one or two hot wires, a neutral wire and a ground wire. If you plan to take on an electrical wiring task yourself, be sure to check the electrical codes in your state and municipality to ensure that your work and materials meet all safety regulations.
  
  

Fixtures, Appliances and Outlets

• All the electricity coming from your panel box has to end up somewhere. When you switch a breaker on and off it controls lights, receptacles and appliances in your house that are directly connected to the individual circuits. Light fixtures and receptacles are directly hardwired to the circuit. Some large appliances such as water heaters and air conditioners are also directly hardwired to a circuit. Depending on the power needed at a specific location, receptacles can be 120 or 240 volts. Large appliances, such as some dryers, need to be placed on a 240-volt circuit with a circuit breaker that can support the voltage requirements of the dryer.