Every year, disasters involving our electrical wiring result in significant numbers of injuries and fatalities. When our home’s electrical line failures remain neglected, they may result in extensive home damage and injury to anybody who comes into contact with them.

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An arcing problem is one of the biggest reasons for causing an electrical fire inside a house. To stop fire hazards brought on by arc failures, The NEMA (National Electrical Manufacturers Association) mandates the installation of AFCI or AFDDs in your houses and buildings.

So, in this article, I will guide you on everything you need to know about arc fault detection devices and how it works to help you with any possible dangers.

What is arc fault detection?

AFDDs (Arc Fault Detection Devices) are safety equipment in household units that can prevent every arc failure from occurring. These devices examine the electricity’s waveforms using some microprocessor technology to look for every unique sign that might indicate an arc within your circuit. Doing so will turn off the electricity to the damaged circuits to avoid causing a fire. Compared to traditional circuit protection systems, these are much more reactive to circuit arcs.

Similar to both an RCCB or the Residual Current Circuit Breakers and the RCBO or the Residual Current Breakers and Overcurrent Protection, The AFDDs often include a testing button that the consumer may press to confirm the device’s mechanical functionality.

Presently, AFDDs are often double the total size of circuit breakers, necessitating a bigger customer unit to handle them. Every AFDD cannot be put in current customer units because of the lack of physical space and the current busbars connecting layout; AFDDs need busbars with active and null connections.

AFDDs are offered to be used in household installations in a range of designs, such as:

  • AFDDs may be fitted in line with an appropriate protective system, such as your circuits breaker or RCBO, as a separate unit following the necessary specifications.
  • They may be fitted as a single unit consisting of AFDDs and a safety feature like circuit breakers or the RCBO.
  • Several suppliers also provide AFDDs modules as add-ons over their other protection systems, but they are only functional with this same supplier’s protective equipment.

AFCI Types

The NEC corporation mandates AFDD protection of the branch circuit wires within the rooms of housing units in order to prevent disasters. Additionally, UL 1699 specifies that the usage of AFCI or ADDD devices must be listed. Various components of the branch circuits and extension wire are meant to be protected by every kind of Arc Fault Detection Devices.

The Branch/Feeder AFCI

To offer AFCI parallels arcing security within the branching or feeders circuit wire. This equipment is positioned at the source of branching circuits or the feeders, like at a distribution board. This technology effectively guards against parallel arcs within the power supply or cable setups. The NEC specifies that this equipment is mandated to be used.

The Outlet Circuit AFCI Type

Next, this equipment, which it will mount at branching circuit outlets, offers AFCI parallel arcing security of the chord connections and electric distribution wires inserted within the main outlet. For the feed-thru branching circuit wires it doesn’t offer any AFCI security.

The Combination AFCI Type

For branching circuits wiring, cable sets, and power supply cables downstream of the gadget, this type of device offers AFCI parallel arcing protection. This thing is usually defined as a receptacle.

According to the UL 1699, Every AFCI must pass a stringent battery of tests and exams that assess its capacity to sense every arc, prevent adverse procedures, and perform electrical inhibit tests. The AFCI will recognize arcing faults even if they are electrically connected in both a series arc or parallel arc that contain loads that might dissipate, cover up, or somehow overlook the arcing notification.

What are the Causes?

The two main frequent places for an arcing defect to happen would be at cable dismissals, wherein connections are really not tightly fastened and were weak, and inside the line component, in which the insulator inside has been affected.

Although there are many other causal factors of wire damage, several of the most frequent ones include rat biting, cables that have been squeezed, jammed, knotted, or poorly managed, along with damage within the insulator from hooks, bolts, or perhaps damaged because of drilling.

Shafted terminations are where faulty couplings most often happen. There are two primary causes for this event; the first would be improper installation-stage connections tightness. The second method uses wires and an electromagnet. The effect of the current stream may definitely result in connections weakening under this strain throughout time.

How does an arc fault detector work?

AFDDs are electrical devices that constantly monitor and detect every waveform of the current passage from one or more circuitry. AFDDs work by cutting off the connection or lines once the device notices a strange signal, like the one produced from an arcing fault inside the waveforms.

All AFDDs were built and evaluated carefully to detect a “regular” arcing, such as the one inside the electric engine powering a hoover but not reacting. Like what I’ve discussed above, some arcs still happen even during the regular running of an electricity supply. Therefore having this device inside your electric system is hugely beneficial.

What are the two types of arc faults?

The Parallel arcs

Parallel arc faults arise whenever an arc forms between the circuit and the ground conductor or neutral conductors. When an arcing fault involves lines and the earth conductors, there will be a strong probability that it will activate the residual-current device (RCD).

The Series arcs

Another kind of arc fault is the series arc fault. This is caused by an arc that develops across two pieces with similar conductors, like a damaged circuit or perhaps an accessory connector that has been improperly stopped.


Overlooked arcing faults may ignite into a house fire within a split second. Damaged conductors commonly cause several arcing faults, weak links, compressed cables, and even deteriorated insulators. It’s not always easy to spot these arc flaws. Most of the time, they may be found in obscure locations, such as broken cables, behind walls, or perhaps sloppy connections inside your fuse box or even electrical sockets. Arcing faults often cause electricity accidents. In older houses, those types of accidents occur at an alarmingly high rate.

Nelson James
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