IEC 60947-9-1-2019 pdf download.Low-voltage switchgear and controlgear – Part 9-1: Active arc-fault mitigation systems – Arc quenching devices.
This part of IEC 60947 covers low-voltage arc quenching devices, hereinafter referred to as AQDs, which are intended to eliminate arc-faults in low-voltage assemblies (typically low- voltage switchgear and controlgear assemblies in accordance with the IEC 61 439 series), by creating a lower impedance current path, to cause the arcing current to transfer to the new current path. This new current path is maintained until a short-circuit protection device (SCPD) interrupts the short-circuit current.
AQDs are installed in low-voltage assemblies, connected to the main circuit, preferably as close as possible to all primary power sources.
Their rated voltage does not exceed 1 000 V AC or 1 500 V DC.
This document does not cover:
• sensors intended to detect arc-faults;
• devices intended to trigger the functioning of the arc quenching device;
• devices intended to interrupt arc-fault current;
• special requirements for AQDs for use in explosive atmospheres (e.g. ATEX).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
IEC 60068-2-30:2005, Environmental testing – Part 2-30: Tests – Test Db: Damp heat, cyclic (12 h + 12 h cycle)
IEC 6041 7, Graphical symbols for use on equipment (available at http://www.graphical- symbols.info/equipment)
IEC 60947-1 :2007, Low-voltage switchgear and controlgear – Part 1: General rules
IEC 60947-1 :2007/AMD1 :201 0
IEC 60947-1 :2007/AMD2:201 4
IEC 61 439 (all parts), Low-voltage switchgear and controlgear assemblies
CISPR 1 1 :201 5, Industrial, scientific and medical equipment – Radio-frequency disturbance characteristics – Limits and methods of measurement
CISPR 1 1 :201 5/AMD1 :201 6
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60947-1 :2007,
IEC 60947-1 :2007/AMD1 :201 0 and IEC 60947-1 :2007/AMD2:201 4, as well as the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1 arc quenching device
AQD device intended to eliminate arc-faults by creating a lower impedance current path in order to cause the arcing current to transfer to the new current path
Note 1 to entry: This note applies to the French language only.
3.2 low impedance state
closed state state where the voltage drop across the AQD is below a defined limit
Note 1 to entry: The limit value is defined in 5.5.
3.3 open state state of the AQD, before operation or after resetting or re-opening (see Clause 4), in which the predetermined dielectric withstand voltage requirements of the main circuit are satisfied
Note 1 to entry: This definition also covers devices without mechanical contacts, for example semi-conductor devices.
4 Classification
4.1 According to the number of operations
4.1.1 Single shot AQD
4.1.1 .1 Not able to be reopened after operating
AQD that:
• is designed and intended to operate only once, and needs to be replaced or refurbished after operation;
• cannot be reopened after operation, and therefore needs to be removed or disconnected from the equipment before the main circuit can be re-energized.IEC 60947-9-1 pdf download.