Commission First Low-Voltage and Medium-Voltage Arc Quenching - Switchgear Projects in North America

Winneconne, WI – Switchgear Power Systems (SPS) has partnered with Tech4 [De Pere, WI] to design, manufacture, and commission the first low-voltage and medium-voltage active arc flash quenching switchgear projects in North America.  SPS’s innovative new design eliminates the need for arc-rated personal protective equipment (PPE), and minimizes damage to critical equipment assets.  The active arc quenching SPS switchgear represents the pinnacle of electrical safety and reliability, able to guarantee the equivalent of PPE Category 0 (less than 1.2 calories per cm2 incident energy at the working distance) without a power system study.  At present, it is the only arc flash mitigation solution able to make this claim.

The new SPS switchgear design meets all the requirements of arc-resistant switchgear compliant with IEEE C37.20.7-2007, and at the same time delivers multiple safety and reliability benefits compared to traditional “arc venting” or “arc redirection” arc-resistant equipment.  Utilizing the Tech4 active arc quenching system, the SPS switchgear maintains its low arc flash hazard rating even with the switchgear enclosure doors open.  Most important, the active low arc flash and equipment reliability benefits are easily extended to downstream electrical assets, such as motor control centers and variable frequency drive (VFD) enclosures. 

For the 4.16kV medium-voltage arc quenching project, SPS utilized Schneider Electric Evolis vacuum circuit breakers in an ANSI-NEMA metalclad switchgear package to replace narrow-width (26-inch) GE Magne-Blast switchgear.  It was the first implementation of the compact Evolis breaker in a drawout metal-clad chassis in North America.  In addition to the narrow cubicle width, the enclosure height was reduced to 80 inches and the depth was reduced to 71 inches.  The resultant design is the safest, most reliable, and most compact medium voltage switchgear solution available in North America.

Installation of arc quenching switchgear reduced the incident energy level from 30 cal/cm2 (Category 4), to 0.4 cal/cm2 (Category 0) at a 36-inch working distance.  The arc quencher protection was also extended to a downstream low voltage switchboard via combination light & pressure sensors.  Because the arc quencher is resettable, in addition to greatly improved operator safety, the arc quenching system maximizes the electrical system uptime.  The system guarantees a total arc flash clearing time of 6 milliseconds (.006 seconds) or less.

The SPS low-voltage arc quencher switchgear solution provided very similar benefits, reducing the arc flash incident energy inside a 4MVA unit substation and a downstream 4,000-amp ABB variable frequency drive from 62 calories per cm2 (PPE Category Dangerous) to 0.25 calories per cm2 (PPE Category 0).  Identical to the medium-voltage quencher, total arc flash clearing time was less than .006 seconds.

“SPS is honored to partner with Tech4 to provide cutting edge solutions to the electrical distribution market.  Our solution increases customers’ equipment reliability while at the same time increasing protection for maintenance personnel” said SPS CEO Greg Shallbetter.

Switchgear Power Systems, LLC is an original equipment manufacturer (OEM) of custom low voltage and medium voltage power distribution equipment including metal-enclosed switchgear, metal-clad switchgear, padmount equipment, and power distribution centers.  SPS serves utility, industrial, critical power (hospital and data center) and commercial customers throughout North America and around the globe, and is recognized throughout the industry for its engineering capabilities and product quality.  www.switchgearpower.com