Strategies for Reliable Arc Flash Detection in Low-Voltage Switchgear

Reliably detecting the ignition of an arc flash inside low-voltage metal enclosed switchgear using an arc flash detection system presents a number of technical challenges and requires careful system design to provide maximum equipment and personnel protection. The proper placement of sensors throughout the switchgear is critical to ensuring reliable arc flash detection. Given the large number of potential switchgear design variations, the best way to ensure reliable arc flash detection is through verification of sensor placement by creating true arcing events at a high power test lab using worst-case switchgear configurations in which the detection system will be applied. This paper will briefly discuss the tradeoffs between fiber optic and wired point sensors and will provide extensive treatment of methods to determine sensor placement, sensitivity and quantity within a given low-voltage switchgear design as well as strategies to avoid nuisance operation of the arc flash detection system.