Electrical System Repair

A home electrical system includes the wiring in a house, the electrical service panel where electricity enters the house, and every electrical switch, electrical receptacle, and other device that allows use of the electrical power provided. This Fix-It Guide tells how an electrical system works. It then refers you to step-by-step instructions for how to repair the specific component or device, including electrical service panel repair, electrical receptacle repair, electrical switch repair and other electrical repairs.

How Does an Electrical System Work?

electricalsystema 1 Electrical System Repair

Components of a typical residential electrical system.

How does electricity do its job? Electrical current flows to the electrical device through a hot (usually black) wire. The current flows back to its source over the neutral or ground wire. Current is the flow of electrons in a wire, measured in amperes or amps. Volts are the pressure that moves the electrons along the wires. Ohms measure the resistance to the flow of an electric current.
Power for most homes comes from a regional power company. Wires bring the electricity to an electrical meter where household usage is measured, then to the electrical service panel, which distributes the power to individual circuits. Household circuits are either 120-volt or 240-volt. The 120-volt circuits power most of a home from lighting to blenders to refrigerators. A few large appliances, such as electric kitchen stoves, dryers, central air conditioners, and water heaters run on 240-volt circuits.


Turn off power before working on any electrical system.

What Can Go Wrong with an Electrical System?

The power source coming into your home can fail. Wires within your home can short out or fail. Circuit breakers can trip and fuses can burn out. Electrical receptacles and electrical switches can malfunction.

Fix-It Tip

Be sure any light, appliance, switch, receptacle, or other electrical device you use has an approval label by Underwriters Laboratory. The label means the device meets safety standards.

How Can I Identify an Electrical System Problem?

  • If all your home’s lights and electric gadgets suddenly quit working, check the electrical service panel to see if the main breaker or fuse has tripped. Also check to see if your neighbors have power. If in doubt, call the power company.
  • If an individual circuit breaker trips or a fuse burns out, check the electrical service panel.
  • If an electrical appliance or device, such as an oven or a blender, quits working, refer to the specific Fix-It Guide for testing instructions.
  • If an electrical receptacle or electrical switch malfunctions, test and replace if necessary.
  • If you suspect a short or wire failure in your house electrical system, call a licensed electrician.

What Do I Need for Electrical System Repair?

Replacement parts for electrical systems are available from local hardware stores, home centers, and electrical suppliers. The tools you will need to fix electrical system components include these:

  • Multimeter
  • Screwdrivers
  • Wrenches

What Are the Steps to Electrical System Repair?

Refer to the specific Fix-It Guide for instructions on fixing the component or device.

Fix-It Tip

Call an electrician if you have any doubts about working on your electrical system or any doubts about your system’s safety.