VD4-AF / VD4-AF1 Vacuum Circuit Breaker for Steel Furnaces

This document describes ABB's VD4-AF and VD4-AF1 medium-voltage vacuum circuit breakers, designed for safe and relentless steel furnace operation and protection up to 38kV, 3150A, and 40kA. It highlights the breaker's ability to perform up to 150,000 close-open operations with limited maintenance, ensuring no downtime for breaker overhaul and reducing total furnace operation costs.