Siemens QJ23B125U Molded Case Circuit Breaker

Siemens QJ23B125U is a 125 A, three-pole molded‑case circuit breaker from the QJ frame family, designed for 240 V AC electrical distribution. It delivers reliable overcurrent protection for three‑phase feeders and branch circuits in low‑voltage panels, combining compact enclosure design with Siemens’ proven trip‑system performance. Rated with a 10 kA interrupting capacity, the unit is capable of safely interrupting fault currents typical of commercial and light industrial installations, helping to protect conductors, transformers, and downstream devices. As a molded‑case breaker, it integrates into Siemens-compatible panels and uses standard QJ mounting and termination practices, enabling straightforward field installation and predictable electrical behavior across the QJ lineup. For proper system coordination, verify the exact trip characteristics and terminal configuration from official Siemens product catalogs or authorized distributors to ensure the part meets your panel’s requirements and upstream protection strategy.