AFDD vs MCB: Which Prevents Electrical Fires? | Ultimate Guide
MCBs protect against circuits being overloaded with electricity by tripping off and stopping the flow of electric current to the circuit. What if there were some type of circuit breaker that would never know how to 'trip' since it could not see what is the number one electrical fire hazard? Thousands of houses every year are burned to the ground as the result of an electrical arc. None of the MCBs currently in use in residential homes has the capacity to detect or 'see' the 'invisible' sparks that can burn down the houses through wood, drywall, and plywood. This is not a small problem; it is a major life safety hazard present in both residential homes and commercial facilities. As you read this document, you will learn that the arc fault detection device (AFDD) and the Miniature Circuit Breaker (MCB) can save your life as a homeowner, renter, or business owner. Which do you believe offers more protection, the AFDD or the MCB, and how do they provide that protection? The AFDD is a "Smart" guardian for your electrical system.
The arc fault detection device (AFDD) is a new, innovative system designed to provide protection to your home's wiring via ongoing, continuous monitoring of the current flow through all of the electrical systems connected to your home (24/7). The AFDD uses advanced, sophisticated technology and microprocessor-based systems to identify and "read" the characteristics of different current types. The arc fault detection device (AFDD) will also identify the "two signatures" of an arc fault as one of the following: either (1) the damaged wire, loose connection, or worn insulation, and/or (2) when an arc fault occurs (meaning when there is a fault). If the AFDD detects a fault in less than 1/100th of a second, it will immediately disconnect the electrical current to the affected circuit and to the entire system, stopping further damage and potential fires.
What is an MCB? The backbone of electrical safety and protection.
MCBs are the first line of defense against electric shock and fire caused by electrical faults. MCBs provide a safe means to isolate an electrical circuit from its power supply by interrupting the current flow to that electrical circuit if, for any reason, that current becomes too high (for example, a blown fuse). This allows you to eliminate the cause of a circuit's sudden rise in current and restore the circuit without any risk of personal injury or damage to property. An MCB (Miniature Circuit Breaker) safeguards against dangerous faults caused by overloads (too many devices drawing power), and short circuits (wires touching). MCBs are an important first step to protect your home's wiring system, but they cannot find lower-level, episodic electrical issues like atmospheric arcs, which have caused thousands of home fires and commercial property fires.
Comparing MCB to AFDD
Where to install
AFDD devices can only be used in new installations. Most will support retrofitting with current wall switches, so you have the option to upgrade to contemporary standards without rewiring your home or building.
Finally, AFDDs must be considered as a necessity of crisis management within the home or workplace to maintain safety.
mcbs provide the first line of defense, but due to arc faults and different electrical failures, they now represent one of many newly created methods by which the occurrence of a fire can happen in homes or facilities where mcbs were first widely available. The installation of an AFDD provides much-needed additional levels of protection against these newly created electrical failure issues.
How To Acquire An AFDD:
- Conduct a five-minute risk assessment of your home to identify the areas of greatest risk: e.g., homes built before 1990, rooms using heaters and/or air conditioners, rooms containing rewired or modified electrical infrastructure.
- Choose an AFDD that is compatible with your mcb's brand and has been tested to the IEC 62606 certification specific to your electrical service panel type.
- Get installation cost (average $200-$600) & requirements (1-3 circuit replacements, including labor) confirmed.
- Engage a licensed electrician to ensure compliance with local ordinances and confirm proper installation and functioning of the AFDD installed.
Frequently Asked Questions About AFDDs and MCBs
Q. Does an AFDD replace an mcb?
A. An mcb will be an integral part of your complete electrical safety protection system, along with your AFDDs—the two devices work together.
Q. Are AFDDs required for all circuits in my home?
A. Not necessarily: You should identify circuits located in higher-risk areas.
Q. How will I know if my AFDD is working properly?
A. Press the test button every month and create a verification as part of your annual inspection.
Q. How much do an AFDD and MCB cost?
A. When an AFDD costs $80-$150 and an MCB costs between $15 and $30.
Q. Are AFDDs required by the current electrical code?
A. Yes—they are strongly encouraged to be installed in defined high-risk areas.
Next Steps to Improve Your Electrical Safety
- Schedule a Free Electrical Safety Assessment.
- Review Our Assessed AFDD Products.