Residential | FPL | Checking Electric Wiring Connections

Checking Electric Wiring Connections

Need for inspection indicators | Results of neglect | Troubleshooting arcing | Proper wiring of electrical outlets | Polarity | Checking polarity

Periodic inspection of the electrical system is recommended to help keep

  • your home safe and
  • its equipment operating properly.

Need for inspection indicators

Your wiring and connections need a thorough inspection, and possibly repair work, if you are experiencing power quality problems such as

  • television and radio interference
  • tripping breakers
  • blown fuses and
  • dimming or flickering lights.

Prevent problems by watching for symptoms of poor electrical connections.

Results of neglect

To provide safe, reliable service, electrical connections should be tight and dry. When they are not, the connection can degrade over time resulting in

  • overheating
  • arcing and
  • possible fire.

Troubleshooting arcing

When connections arc, you may notice the symptoms of electrical noise arcing, such as

  • radio or
  • television interference.

The table below describes what to do if you detect arcing in your home.




Isolate the faulty circuit by turning off the breakers at your main panel one at a time until the interference disappears.


Call a qualified electrician to inspect the entire electrical system.


Inform the contractor about the circuit you have identified.

Proper wiring of electrical outlets

A standard outlet has three holes for each plug:

  •  Two vertical rectangular slots and
  •  One rounded slot centered
    • between and
    • slightly below the other two.

The table below describes the characteristics of a properly wired electrical outlet.



Rounded Slot

The ground connection, which is for safety.

Larger Vertical Slot

The neutral connection, which returns the electrical current used in your appliances back to the source.

Smaller Vertical Slot

The energized conductor, which sends the electrical current to the appliance (also called the hot leg).


Some home appliances have polarized plugs, where one of the two prongs is larger than the other. This ensures the proper polarity when they're plugged into a standard outlet. If any of the wires in the outlet are connected to the wrong slot, the equipment can malfunction, creating a potential health hazard.

Checking polarity

It is easy to check polarity at an outlet. Most home supply stores sell a device for less than $10 that will tell you if the outlet is properly wired.

Warning: If you check an outlet with a polarity tester and the unit shows an improper condition, have a qualified electrician inspect the electrical system.