Tag: fire prevention

Dear Mr. Electrician: What is the reason for Arc Fault Circuit Interrupters or AFCI? Answer: Arc Fault Circuit Interrupters provide an additional level of protection against fires.  Electrical arcs create heat and sparks.  If combustible materials are nearby, a fire could erupt.  Arc Fault Circuit Interrupter circuit breakers protect us from potential fire starters we cannot see. Table of Contents: Types of Arc Faults Causes of Arc Faults Other Issues That Cause Arc Faults AFCI Trip Indicator Guide NOTE: Some text links below go to applicable products on Amazon.  As an Amazon Associate, I earn from qualifying purchases.  Using my links helps to keep this website FREE. Many residential homes have wood frame construction.  The walls' electrical switch and receptacle boxes are attached to wood framing members.  The electrical wiring runs through the wood framing.  Wood is a combustible material.  If heat and sparks develop inside the wall, you will not know it until it becomes obvious. An early warning indicator for possible loose connections is blinking or flickering lights.  If you see lights flickering fairly regularly, you may have a loose connection somewhere or something else is going wrong.  Have a professional electrician look into it for you. Top Of Page TYPES OF ARC FAULTS DETECTED BY ARC FAULT CIRCUIT INTERRUPTERS A Series Arc or low current arc can be as a result of frayed power cords, old appliances, or loose electrical connections. A Parallel Arc or high current arc can occur from a screw or nail being partially driven into a live wire, causing a poor connection to be made between two current-carrying conductors.  Also known as a line-to-neutral arc. Line-To Ground Arc or ground fault indicates electrical current leaking to earth ground. A combination Arc Fault Circuit Interrupter will protect against the three types of arcs.  However, a combination AFCI will not have GFCI protection.  You need a dual-function circuit breaker for both AFCI AND GFCI protection. Top Of Page CAUSES OF ELECTRICAL ARC FAULTS An electrical arc can be caused by lightning, of course, and your grounding electrode system should handle that if it is in good condition. However, other arcing causes are usually not as obvious until some damage or a fire occurs.  For instance, an electrical receptacle with a loose connection may be fine until one winter, you decide to plug a high-wattage portable electric heater into it. The heater uses a lot of current to keep you warm.  With the extra LOAD on the electrical circuit, the loose connection that was working fine for a few years now arcs each time the heater is on. I found the above electrical outlet inside a kitchen cabinet for the over-the-range microwave oven.  It was not installed by someone qualified.  In addition to the loose connection that caused the arcing and subsequent burning, there was no connector in the back of the box to protect the cable from the edges of the metal electrical box.  The knockout was punched out but is still attached to the box. The electrical box was also not grounded properly.  A ground wire connection should have been...