Siemens QJ23B125 Three Pole 125 Amp Circuit Breaker

Siemens QJ23B125 is a three-pole, 125-amp low-voltage molded-case circuit breaker (QJ2 frame) rated for 240 VAC operation with a 10 kA short-circuit interrupt rating, providing thermal-magnetic overcurrent protection for feeders and equipment in commercial and light-industrial panels. The model designation identifies a 125 A, 3-pole device designed to interrupt faults on a 240 V system, with long-time and instantaneous-trip characteristics to coordinate protection and reduce nuisance trips. As part of the Siemens QJ family, it is compatible with standard QJ frame mounting and panel installations used for residential and commercial distribution, motor circuits, and control panels that are supplied from around 120/240 V service. The QJ23B125 delivers reliable protection through a thermal-magnetic trip mechanism, designed to respond to sustained overloads and instantaneous faults to safeguard wiring and connected equipment. Typical applications include feeders and branch circuits in distribution panels, control panels, and motor-control setups where 125 A protection at 240 V is required. For precise installation wiring configurations, mounting specifics, and replacement compatibility within the QJ-series, refer to the official Siemens data sheet and your local distributor guidance.