AFCI and GFCI Circuit Interrupters

AFCI Arc Fault Circuit Interrupters

AFCI’s or Arc Fault Circuit Interrupters are a relatively new innovation.  They are available both as breakers and receptacles or as Dual protection when combined with GFCIs.  They shut off power if arcing occurs.   Conventional overcurrent protective devices do not detect low level hazardous arcing currents that have the potential to initiate electrical fires so an arc can well happen without even tripping your breaker.  An electrical arc is the result of a charge passing between two wires and is a major cause of electrical fires as the spark can be quite hot and occurs inside the walls where it might not be noticed until the fire has grown.  An arc fault is an unintended arc created by current flowing through an unplanned path. Arcing creates high intensity heating at the point of the arc resulting in burning particles that may easily ignite surrounding material, such as wood framing or insulation. The temperatures of these arcs can exceed 5500 degrees Celsius, paper for instance, burns at 230 degrees Celsius, wood on average burns at around 500 degrees Celsius  and copper melts at 1085 degrees Celsius so it is obvious that an arc could set fire to just about anything that can burn and can totally and easily disable the wiring in a circuit, melting the insulation and creating an even larger area where an arc can occur. This is not only a risk in older houses where insulation on old wiring has begun to get frayed but can occur anywhere the insulation has been damaged for instance if a nail is driven into the wall at the wrong spot and nicks the wires inside the wall.  They are now required by the electrical code in new or remodeled bedrooms.  They are neither expensive nor difficult to install so it is a very good idea to make this particular circuit upgrade.  

How does an AFCI Work?

Regular circuit breakers and GFCI’s can detect overloads and short circuits but the AFCI has advanced sensors to detect arcs formed under a variety of conditions.  There is different technologies employed by different AFCI manufacturers but they all perform by  detecting parallel arcs (line to line, line to neutral and line to ground) and/or series arcs (arcing in series with one of the conductors).

How does arc fault detection work? AFCI’s are the product of advanced electronic technology and can detect arcing conditions of any kind including safe and unsafe arcs.  Safe arcing occurs when you run an electric motor like your vacuum cleaner or sometimes when you turn on a light switch.  Anywhere you might see a spark occurring is where you find an arc.

A dangerous arc, as mentioned earlier, occurs for many reasons including damage of the electrical conductor insulation. When arcing occurs, the AFCI analyzes the characteristics of the event and determines if it is a hazardous event. AFCI manufacturers test for the hundreds of possible operating conditions and then program their devices to monitor constantly for the normal and dangerous arcing conditions.  Your circuit breakers and GFCI outlets are electrical in nature rather than being the product of electronics and so are correspondingly much less sensitive to what is happening in your power lines.

If your AFCI has been tripped it is best to call in HouseDepot right away to inspect the faulted circuit unless the arc has occurred in  a power cord or electrical device which can be unplugged instead of your internal wiring.

GFCI Ground Fault Circuit Interrupters

GFCIs, or ground fault circuit interrupters, protect against the risk of electrical shock. They are inexpensive and easy to install.  They are required by code wherever there is increased risk of electric shock such as kitchen, bathroom or outdoor outlets.  

What is a GFCI outlet?

GFCI outlets can be easily identified as they are equipped with both a “TEST” and “RESET” button.  They should be used wherever there is increased risk of electric shock and are used around pools and spas, in kitchens, bathrooms and garages.  They are necessary to protect you from electric shock by checking the amount of electrical current flowing in the circuit and tripping the circuit to shut off the flow of power to the receptacle before the electricity can cause any harm to people or property.  

How To Test and Operate a GFCI Outlet

If a GFCI outlet trips for one reason or another and there is no further danger of electric shock then the “RESET” button will restore power.  Note that there is no warning when a GFCI circuit trips so that appliances like refrigerators, freezers or other appliances which require power at all times should not be plugged into GFCI outlets.  GFCI’S are much more sensitive to changes in current and can even shut off the flow of power before the electricity can affect your heartbeat.  Because of this it is a good idea to check your GFCI outlets every month to make sure they have not tripped and are in need of resetting and make sure they properly shut off the flow of power.  Plug in a small light or some other easily observable thing that uses only a little power and press the “TEST” button to make sure the power gets shut off correctly.  Then press the “RESET” button to turn it back on.

Where should you have GFCI outlets?

GFCIs are necessary anywhere that the risk of getting electrocuted is greater, usually around areas where there is or could be water.  They are required by code in the following areas:

  • Bathrooms and Kitchens
  • Around Laundry and Utility sinks
  • Wetbars
  • Garages
  • Crawlspaces and unfinished basements
  • The exterior of your house
  • Spa and pool areas

Many older homes still lack GFCI’s and to be safe you should contact HouseDepot to have them put in as quickly as possible.  It is not expensive and it could save your life.