Metal-clad switchgear that includes a fast-acting low-impedance arc-mitigation device (arc-quencher) that limits the incident energy from an arc-flash incident to less than 1.2 cal/cm2.

The SPS-AQS system utilizes a combination of light, current, and pressure sensors, and is resettable to allow rapid return to service of equipment.  The SPS-AQS protective relay system responds to arc flash events in less than 1 ms, relying on at least two different types of sensor inputs (such as current and light), before activating the arc quencher to create a three phase low-impedance parallel path for fault current to flow.  The total time from arc detection to the elimination of the arc is 6ms, limiting the available incident energy to less than 1.2 calories per cm2 at the working distance, and the protection can easily be extended to downstream assets such as MCC’s and VFD’s. 

The arc quencher and arc flash protective relays have been tested and validated by third party independent laboratories, and comply with all applicable electrical standards, both IEC and ANSI/NEMA.