What Is Electrical Service?

Electrical Service is the point where the main wires from the utility enter your home. Depending on the type of power your house uses, the electrical service panel may be located in your garage, basement or utility area.

It may also be contained in a finished cabinet mounted on an exterior wall.
Electrical Panels

The electrical panel is a vital component in the operation of your entire home’s electrical system. It receives the incoming power from the utility company, then distributes it to all of the outlets, switches and appliances in your house. It’s important to know exactly how it works so that you can understand what’s happening when your breaker trips or you need to make an electrical repair.

Electrical panels are usually located in out-of-the-way places such as basements, garages, or laundry rooms. They often have a metal enclosure that prevents water from getting on the wiring, contains electrical discharges and keeps dust and pollutants at bay.

The main electrical panel is usually arranged in two columns with individual circuit breakers. There is a main disconnect switch at the top that shuts off the current to the whole breaker box. Hot source wires connect to this, and then to the hot busbars running down the center of the breaker box.
Wiring

Electrical wires are the lifeline that connects switches, outlets, appliances, and other devices to your main service panel. Wires are a critical component to any electrical system and their integrity needs to be carefully maintained.

Wires and cables have a circuit voltage rating, conductor surface temperature rating and an environment (moisture, oil, chemicals) rating that dictates what they can safely carry. They must be sized correctly for your installation.

The main electrical service reaches your home through overhead wires that enter a service mast and pass through an electricity meter or underground lines that enter your home. The homeowner is responsible for furnishing and maintaining the weatherhead, mast, meter socket, disconnect, and grounding. Green/yellow striped wires are safety earthing (grounding) connections that must be identified by color-coding to reduce the likelihood of dangerous confusion with ungrounded “hot” wires, especially by persons suffering from red-green color blindness.
Breakers

The main breaker in your electrical panel controls the flow of electricity from the two wires coming into the panel to your branch circuit breakers. The main breaker is rated to handle a certain amount of current, usually between 100 and 200 amps.

When a breaker is overloaded, it will trip and interrupt the flow of power to prevent excess current from flowing through it and damaging your wiring or appliances. If the breaker in your home trips frequently, it may be time to add more breakers or upgrade your service panel.

Always shut off power to the breaker before working on any electrical work at home. Unless you are experienced with opening and closing the dead front cover of a breaker panel, it’s best to leave any electrical work requiring removal of the panel’s dead-front cover to a professional electrician. Attempting to remove the dead-front cover of a breaker panel can cause dangerous levels of voltage to be released, which could result in electrocution or injury.
Switches

A switch interrupts an electric circuit by opening and closing the contacts. When the switch is open, electricity cannot flow through a device like a light. When the switch closes, the current flows through the device and turns it on.

There are many different types of switches, but they all operate similarly. They consist of an operator, low-resistance metal contacts, and a mechanism that opens and closes the contactors to create and break the circuit.

Switches have a maximum current rating that they can safely carry. This is the amount of electric current that can flow through the switch before it starts to suffer physical damage such as overheating and deformation.

If a breaker trips repeatedly, it may be overloaded. You can check this by opening the service panel and looking at all of the switches. If one is still on, then it is likely that you need to turn off appliances in that circuit until the breaker can be fixed.