Understanding the Home Electrical System for Realtors, Home Inspectors, and Homeowners – Lesson 1: The Electrical Service

The electrical service for a home is analogous to the motor of a car. It provides the power to drive the home’s electrical usage — from the refrigerator to the lights — just like a car’s motor provides power to the wheels. Both consume energy and provide us with modern comforts or transportation.

The Electrical Service for a home is comprised of four main components. Understanding them is useful when buying, selling, inspecting, or maintaining a house.

1. The Meer Loop and Meter Enclosure: This is the beginning of the home’s electrical system. The house connects to the utility wiring at the Service Point which is the taped connections at the weatherhead, in an overhead service and the underground splices at the hand hole, or vault in an underground service. It is important to observe the age and condition of this equipment when buying or selling a home.  Check that the meter ring has the utility seal and verify that the overhead connections are the permanent type made by the utility company and not the temporary ones made by an electrician.

2. The Service Entrance: This is the conduit and wire that connects the meter to the home’s electrical distribution panel. Check that conduit is installed to protect the entrance wires and the penetration into the building is caulked.

3. The Electrical Panel: “The breaker box” as it is commonly called protects the home and its occupants from the consequences of overloads and shorts. Red Flags are electrical panels that have fuses rather than circuit breakers; and Zinsco; Federal Pacific; Pushmatic; and Split Bus type breaker boxes.

4. The Grounding and Bonding System: 

  •  *Part A* the grounding system can route high fault currents from the utility company or a lighting strike away from the house and may have other benefits.
  • *Part B*  the bonding system in a properly wired home will protect people from electrocution and house fires.  A properly installed bonding system, which includes three-pronged “grounded” receptacles is far more important than the grounding system of a house. The grounding system may divert a surge away from electronics saving some financial loss. The bonding system will shut down the home’s electricity when there is a ground fault or an overload to the wiring.