The Acti9 AFDD can be used in DIN rail distribution boards for:

The European installation standard IEC 60364-4-42, recommends the use of AFDD to protect against arc fault in final circuit:

in locations with sleeping accommodations (e.g., hotels, nursing homes, bedrooms in homes)
in locations with risks of fire due to high quantities of flammable materials (e.g., barns, wood-working shops, stores of combustible materials)
in locations with combustible constructional materials (e.g., wooden buildings)
in fire propagating structures (e.g. high-rise buildings)
in locations where, irreplaceable goods are housed (e.g., museums).
The Acti9 AFDD must not be installed on circuits requiring a high level of continuity of service.
The Acti9 AFDD is not compatible with ATEX regulations.