IEC 60947-9-1 :2019 pdf download – Low-voltage switchgear and controlgear – Part 9-1: Active arc-fault mitigation systems – Arc quenching devices.
4.1.2 Resettable AQD AQD that is designed and intended to operate a number of times, as specified by the manufacturer. 4.2 According to the mounting characteristics 4.2.1 Fixed AQD AQD directly mounted and connected in the assembly, so that it is necessary for the operator to come into contact with the main circuit conductors to replace it. 4.2.2 Withdrawable or plug-in AQD AQD mounted in a draw-out cradle, or plugged on a fixed base, so that it can be easily replaced after operation, or maintained, without the operator coming into contact with the main circuit conductors. 5 Characteristics 5.1 Rated operational voltage (U e ) Subclause 4.3.1 .1 of IEC 60947-1 :2007 applies. 5.2 Rated insulation voltage (U i ) Subclause 4.3.1 .2 of IEC 60947-1 :2007 applies. 5.3 Rated impulse withstand voltage (U imp ) Subclause 4.3.1 .3 of IEC 60947-1 :2007 applies. 5.4 Rated short-time withstand current (I cw ) The rated short-time withstand current of an AQD is the RMS value of current that the device is able to make and carry without damage for a given duration, under the test conditions specified in Clause 9. There may be different values of current associated with different durations. The duration associated with the rated short-time withstand current shall be at least 0,05 s, preferred values being as follows: 0,05 s – 0,1 s – 0,2 s – 0,3 s – 0,5 s – 1 s 5.5 Maximum voltage drop in low-impedance state Maximum peak value of voltage between the main circuit terminals of the AQD, in the low- impedance state, when carrying the current corresponding to its rated short-time withstand current. This value shall be not greater than 34 V (peak). NOTE The value of 34 V (peak) has been defined to ensure proper arc quenching (see Annex A).
5.6 Maximum operating time Maximum time between receiving the triggering signal and the AQD steadily reaching the low- impedance state. NOTE “Steadily” means that the voltage drop stays below the maximum value stated by the manufacturer (see 5.5). 5.7 Number of operating cycles (of a resettable AQD) Number of trip-reset cycles assigned by the manufacturer to a resettable AQD and minimum interval between two operations. 5.8 Maximum permissible temperature of the AQD main circuit terminals Maximum value of permissible temperature of the AQD main circuit terminals based on the material properties (see 8.1 ). 6 Product information 6.1 Nature of information Subclause 5.1 of IEC 60947-1 :2007, IEC 60947-1 :2007/AMD1 :201 0 and IEC 60947-1 :2007/AMD2:201 4 applies, as far as appropriate for a particular design. 6.2 Marking An AQD shall be marked in a durable manner; data to be provided and corresponding locations are given in Table 1 .
Parts of insulating materials necessary to retain current-carrying parts in position shall be compatible with the maximum permissible main circuit terminal temperature declared by the manufacturer (see item 1 7 of Table 1 ). Where, in 7.1 .2.2 of IEC 60947-1 :2007, IEC 60947-1 :2007/AMD1 :201 0 and IEC 60947-1 :2007/AMD2:201 4, the test temperature is to be specified, the value required by this standard is 850 °C. AQDs shall be provided with a local indicator showing the state (open or closed) of the device. This indicator shall be visible when installed and with the AQD compartment door open. This information shall also be available remotely, through an auxiliary contact or equivalent, to provide electrical interlocking with the upstream SCPD. NOTE 1 This interlocking is to ensure that the circuit protected by the AQD cannot be re-energized until the device has been replaced, re-opened or reset. NOTE 2 One or more additional auxiliary contacts can also be provided for optional interlocking with other devices, such as the external detection device. Single shot AQDs able to be re-opened after operating shall be provided with an additional indicator showing, after re-opening, that the device is “open”, but not ready to operate anymore. This indicator shall be visible when installed and with the AQD compartment door open. Resettable AQDs shall be provided with means to count the number of operations. A means to indicate that the maximum number of operations has been reached shall be provided in that case. AQDs that have provisions for disabling the quenching function shall have provisions for local and remote indication that the device has been disabled. If AQDs contain items that have stored charges after disconnection from the power supply (capacitors, etc.), means shall be provided either to prevent access to these items during normal service, or to discharge them before access is possible.