The Ferraz Shawmut ST320-4M Surge-Trap Surge Protection Device is an industrial-grade 3‑phase surge protector designed for 277/480V systems operating at 50 or 60 Hz. The ST320-4M model belongs to Ferraz Shawmut’s Surge‑Trap line and provides dedicated transient surge protection for 3‑phase electrical distributions using standard 277/480V power supplies.
