This International Standard applies to arc fault detection devices (AFDDs) for household and similar uses, intended to be used in a.c. circuits, for rated voltages not exceeding 440V a.c, with rated frequencies of 50Hz, 60Hz or 50/60Hz and rated currents not exceeding 63A. NOTE1 In the USA, Arc Fault Circuit Interrupters (AFCI) are considered similar to AFDDs. An AFDD is designed by the manufacturer: either as a single device having opening means able to open the protected circuit in specified conditions; or as a single device integrating a protective device; or as a separate unit, according to AnnexD assembled on site with a declared protective device. The integrated protection device is either a circuit-breaker in accordance with IEC60898-1 or an RCD in accordance with IEC61008-1, IEC61009-1 or IEC62423. These devices are intended to mitigate the risk of fire in a final circuit of a fixed installation due to the effect of arc fault currents that pose a risk of fire ignition under certain conditions if the arcing persists. Protection against fire ignition due to overvoltage due to a broken neutral within a three phase installation to be included in this type of equipment as an additional option is under consideration in 9.22. NOTE2 Tracking current leads to arcing and therefore may ignite fire. This International Standard applies to devices performing simultaneously the detection and discrimination of arcing current with regards to fire hazards and defines operating criteria under specified conditions for the opening of the circuit when the arcing current exceeds the limit values given in this standard. AFDDs complying with this standard, with the exception of those with an uninterrupted neutral, are suitable for use in IT systems. Text deleted AFDDs energised from batteries or a circuit other than the protected circuit are not covered by this standard. AFDDs provide isolation, they are intended to be operated by uninstructed persons and do not require maintenance. Particular requirements may be necessary for: AFDDs incorporated in or intended only for association with plugs and socket-outlets or with appliance couplers for household or similar general purposes; AFDDs intended to be used at frequencies other than 50Hz or 60Hz. NOTE3 For AFDDs incorporated in, or intended only for socket-outlets the requirements of this standard can be used, as far as applicable, in conjunction with the requirements of IEC60884-1 or the national requirements of the country where the product is placed on the market. NOTE4 In the UK, the plug part and the socket-outlet part(s) need not comply with any IEC60884-1 requirements. In the UK, the plug part shall comply with BS1363-1 and the socket-outlet part(s) shall comply with BS1363-2. Special precautions (e.g. surge protective devices) may be necessary when excessive overvoltages are likely to occur on the supply side. The requirements of this standard apply for standard conditions of temperature and environment. They are applicable to AFDDs intended for use in an environment with pollution degree 2. Additional requirements may be necessary for devices used in locations having more severe environmental conditions. NOTE5 AFDD for d.c. applications are under consideration.