Optical sensors (for light) and current transformers (for overcurrent) identify the arc fault.
The UFES manual outlines a specific sequence of events triggered by a fault: abb+ufes+manual
Three units that create the metallic short-circuit in less than 1.5 ms. Optical sensors (for light) and current transformers (for
A micro-gas generator in the PSE creates a low-impedance path to ground, causing the arc voltage to break down. abb+ufes+manual
The electronic unit sends a trip signal to the PSE in less than 1 ms.
The feeder circuit-breaker finally shuts down the resulting controlled earth fault current. Technical Specifications UFES | ABB - Core components
The arc is extinguished in less than 4 ms total—20 times faster than standard protection.
