| IEC Standard | Description |
|---|---|
| IEC60947-1 | General rules for Low-voltage switchgear and controlgear |
| IEC60947-2 | Circuit Breakers |
| IEC60947-3 | Switches, disconnectors, switch disconnectors and fuse combination units |
| IEC60947-4 | Contactors and motor-starters 1-Electromechanical contactors and motor-starters 2-AC semiconductor motor controllers and starters 3-AC semiconductor controllers and contactors for non-motor loads |
| IEC60947-5 | Control circuit devices and switching elements 1-Electromechanical control circuit devices 2-Proximity switches 3-Requirements for proximity devices with defined behaviour under fault conditions (PDDB) 4-Method of assessing the performance of low-energy contacts – Special tests 5-Electrical emergency stop device with mechanical latching function 6-DC interface for proximity sensors and switching amplifiers (NAMUR) 7-Requirements for proximity devices with analogue output 8-Three-position enabling switches 9-Flow rate switches |
| IEC60947-6 | Multiple functionequipment 1- Transfer switching equipment 2-Control and protective switching devices |
| IEC60947-7 | Ancillary equipment: 1-Terminal blocks for copper conductors 2-Protective conductor terminal blocks for copper conductors 3-Safety requirements for fuse terminal blocks 4-PCB terminal blocks for copper conductors |
| IEC60947-8 | Control units for built-in thermal protection (PTC) for rotating electrical machines |
| IEC60947-9 | Active arc-fault mitigation systems – Arc quenching devices |
What causes arc flash?
An arc flash causes a very loud sound created by quickly-moving air, or a sound wave, that can reach 140 decibels at a distance of