What Is Your Electrical Service?
The electrical service is the group of wires that connect your homes power usage meter and distribution panel to the power lines coming from your electricity provider. The size or capacity of your electrical service is measured in amps. Newer homes may have 200 amp service while older homes might have 100 or even 60 amps. The demand on your electrical system can increase from time to time depending on the season and the activities that are being performed in your home. Having adequate power in your home is crucial for safe operation of appliances and electrical outlets.
In the US most residential houses have a single-phase electric service of 120/240 volts. This is usually the result of a standard sized electrical panel being connected to two ungrounded conductors (line 1 and line 2) and one bonded, or neutral, conductor at the utility pole. This type of service costs the utility company less to supply as only two transformers need to be installed on the pole.
This same type of service can also be found on some commercial properties as well. This is typically referred to as a 208Y120 electric service and can be identified by looking at the lateral service wires as well as the breaker panel descriptions. The 208Y120 service consists of three wires going to the meter socket with the first two being hot and the third is the neutral. The voltage between the two hot legs is 240V and this can power larger loads in the house such as electric water heaters and air conditioners. The neutral carries 120V and powers smaller loads such as lights and outlets.
When you look at your homes electrical panel you will see a number of individual circuit breakers with small toggle levers. Each one of these circuit breakers has a label that tells what amperage it controls. The panel also has a main breaker that is labeled as such and can be used to shut off the entire service to your home.
A meter is installed on your homes electrical service and it records each month the amount of electricity that is being consumed in the house. The meter is a valuable piece of equipment for the electric utility company as it can be viewed and monitored by the utilities crews to monitor any unusual activity that might indicate a problem.
It is important to understand that the homeowner is responsible for furnishing and maintaining the weatherhead, mast, meter box, meter disconnect, and grounding. The utility company is responsible for the service drop, meter socket and the meter itself.
When the meter is disconnected from the service it must be done with an approved safety switch that can only be operated by the homeowner. If you are planning a new or major upgrade of your electrical service we require that you submit to the City’s Electrical Inspection Department, a full set of construction plans with existing/proposed location of the electrical service panel and meter, a complete panel schedule that indicates any new receptacles, switches, fixtures or wiring (only required if new work is being performed), a service sizing calculation completed by a licensed Illinois design professional and an updated meter connection diagram.