According to GE, ArcWatch is the industry’s first technology to enable an electrical system design that helps to maximize selectivity, or uptime, while simultaneously providing continuous arc-flash mitigation protection.
Arc-flash mitigating technologies generally provide protection with part-time or manual user activation, which creates a mode of either safety or reliability (selectivity), but not both at the same time. Containment mitigation systems primarily redirect away from the operator to “enclose” the impact. These systems also are part-time or manual where human intervention can inadvertently negate their design.
ArcWatch technology works through a combination of communication algorithms across the GE portfolio of circuit breakers by using instantaneous zone selective interlocking and waveform recognition to ensure only the circuit breakers nearest to the fault trip, which happens in as little as 4 milliseconds. This limits the incident energy in the event of an arc flash, protecting both people and equipment.
In a real-world example like a hospital complex with an emergency room, operating rooms, an intensive care unit and patient rooms, trouble-shooting or maintenance is done when the system is live. Full-time, always-on ArcWatch technology means that the system is always selectively optimized for reliability so that if a patient in Room 101 drops a hair dryer in a sink full of water, the circuit breaker for that room will trip to protect that patient from shock, but power will not be lost in the entire wing of the hospital. In addition, the electrical contractor working on an energized system can be protected without requiring human intervention to change modes from reliability to safety.
Systems embedded with ArcWatch technology reduce the impact of an arc-flash event to <8 cal/cm2, resulting in much lower requirements for using personal protective equipment. The use of fire-resistant clothing instead of a full-protective arc-flash suit makes it easier for electrical contractors to work with their hands.