Electrical Service is the connection between the external wires coming from the street and your homes internal wiring system. This is where the power comes from and the voltage is controlled. It is very important to understand that getting a proper Electrical Service can keep you safe from any potential risks that electricity may present.
Most homes in the United States have a 100-amp single phase electrical service. This type of service usually has two ungrounded conductors that are known as Line 1 and Line 2 and one grounded, neutral conductor that is bonded to the ground. The voltage from Lines 1 and 2 is 240V and this is used to power larger loads in a home like electric hot water heaters and air conditioners.
A home’s electrical service panel is located near the electric meter and contains breakers that distribute the electricity to switches, outlets, and appliances throughout the house. The breaker boxes also contain fuses that protect the wiring. The fuses and breakers are located behind a metal door that must be opened to shut off the power.
The breaker box also has individual circuit breaker slots that have small toggle levers that are numbered and control the different branch circuits running through the house. The branch circuits are powered by larger feeder circuits which connect to the breaker box. During the electrical design process, engineers calculate the amount of power required for each circuit and then determine the proper conduit and wiring sizes.
When determining how much power is needed for a new build or renovation, several factors are considered including the square footage, number of occupants, and electrical appliances. The size and amount of electricity use will change throughout the year depending on the seasons. A home that uses electric heat during the winter will require more electricity than a home that does not. The electric meter is read monthly and the total usage is recorded and reported to the utility company.
The electrical service panel can be found inside a gray metal box mounted in a utility area or it can be contained within a finished cabinet on the wall. It must be easily accessible for a home inspection to be performed. In some cases, the main service panel is located outdoors on an exterior wall of the house.
A home owner may be responsible for changes to the overhead service drop, but this will depend on the responsibilities of the local utility company. There must be a minimum of 10-feet of clearance between the ground and the lowest part of the weather head, mast, and meter socket. There must also be an 18-foot clearance over public streets, alleys, roads, parking areas that may have truck traffic and driveways on commercial properties. This allows firefighting and emergency rescue personnel to safely access these services in the event of an incident. The utility company is responsible for maintaining the meter socket, disconnect, and service drop.