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Arc Fault Detection Devices - AFDD

Fires caused by electrical equipment continue to be a significant issue in many Electrical Installations. These Electrical fires can cause injuries, deaths, and damage or destroy significant amounts of property.

The use of circuit breakers, fuses and RCDs greatly reduces the risk of fire, but they can't detect electrical arcing in cables and connections, that silently can cause fires.

Arc Fault Detection Devices (AFDDs) are designed to detect low level hazardous arcing that circuit breakers, fuses and RCDs are not designed to detect.

The image below shows the enhanced protection scheme recommended in the 18th Edition compared to the existing levels of protection offered by protective devices.

The new 18th Edition Regulation, coming in effect on the 1st of January 2019, is addressing these issues by recommending the use of AFDDs, in accordance with BS EN 62606 as an enhanced level of protection against fire caused by arc faults in AC final circuits (Reg. BS7671:2018 - 421.1.7).

In accordance with BS7671:2018, the installation of AFDDs is recommended for AC final circuits in:

  • premises with sleeping accommodation,
  • locations with a risk of fire due to the nature of processed or stored materials, i.e. BE2 locations (e.g. barns, woodworking shops, stores of combustible materials)
  • locations with combustible constructional materials, i.e. CA2 locations (e.g. wooden buildings)
  • fire propagating structures, i.e. CB2 locations
  • locations with endangering of irreplaceable goods

The Requlation also states: "If used, an AFDD shall be placed at the origin of the circuit to be protected".


Using an AFDD in ElectricalOM is straightforward with just a simple click:

First, navigate to the final circuit you would like to use the AFDD and at the Protective Devices tab check the option "Combined Arc Fault Detection Unit".

Note: AFDD can be installed only in final circuits when using MCB or RCBO up to 63A.

Using the AFDD will refresh the schematic to reflect the selection and also will be indicated in the schedule reports.

 



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