Siemens BQD320 Molded Case Circuit Breaker 3-Pole

Siemens BQD320 is a bolt-on molded‑case circuit breaker rated for 20 A in a 3‑pole configuration for 480Y/277 V three‑phase systems, designed to protect feeders and branch circuits in commercial panels and switchgear. It uses a thermal‑magnetic trip mechanism and delivers a 14 kA interrupt rating, suitable for standard fault clearing at 50/60 Hz in typical distribution networks. The unit is panel‑mountable with bolt‑on installation and measures roughly 4 inches long by 3 inches wide by 3 inches high, and it accepts conductors from 12 to 6 AWG aluminum or 14 to 6 AWG copper, aligning with common wiring practices in MCCB installations. Catalog number BQD320, this breaker belongs to Siemens’ BQD/CQD family and is specified for 480Y/277 V operation in a three‑pole, bolt‑on format intended for panelboard applications where compact, reliable overcurrent protection is required.