Siemens BQD3100 U Three-Phase Circuit Breaker

Siemens BQD3100 U is a 3-pole molded‑case circuit breaker rated for 100 A at 480 V AC, intended for panelboard mounting in commercial and industrial power distribution. It provides thermal‑magnetic overcurrent protection with a 14 kA short‑circuit interrupt rating and UL 489/CSA‑C22.2 listings, ensuring reliable protection for feeders and branch circuits. The unit fits Siemens BQD3100 panelboard footprints and measures roughly 3 in wide by 3 in high by 4 in deep, making it compatible with standard three‑phase 480/277 VAC systems. This 3P breaker is commonly used to protect 100 A feeders in 277/480 V AC panelboards and other distribution equipment in commercial facilities.