Abb+ufes+manual Instant

The UFES is a combination of high-speed electronics and primary switching elements (PSE) designed to initiate a controlled three-phase short-circuit to earth. The system typically consists of:

A micro-gas generator in the PSE creates a low-impedance path to ground, causing the arc voltage to break down.

The feeder circuit-breaker finally shuts down the resulting controlled earth fault current. Technical Specifications UFES | ABB - Core components abb+ufes+manual

The electronic unit sends a trip signal to the PSE in less than 1 ms.

Uses external detection devices like the ABB Arc Guard System™ TVOC-2 or REA arc protection for large-scale monitoring. Operational Workflow The UFES is a combination of high-speed electronics

The UFES manual outlines a specific sequence of events triggered by a fault:

An expandable unit with internal light and current detection for small protection zones. Technical Specifications UFES | ABB - Core components

Three units that create the metallic short-circuit in less than 1.5 ms.

Optical sensors (for light) and current transformers (for overcurrent) identify the arc fault.

The arc is extinguished in less than 4 ms total—20 times faster than standard protection.