The Siemens AMP BOLT-ON CIRCUIT BREAKER 3 POLE 480Y/277 VAC BQD390 is a circuit protection device from Siemens. It serves as the protective device in an electrical circuit, stopping current flow when a fault is detected. Key specifications noted on this listing include 277 VAC, 90 AMP, 3 POLE. It is commonly in panel builds and electrical system retrofits.
