Siemens QJ23B225 Molded Case Circuit Breaker

This unit is engineered to integrate into Siemens meter centers, panelboards, and switchboards configured for unit-mounted QJ or QR frame breakers. Check your enclosure interior labeling to verify QJ frame compatibility.

Yes. Siemens introduced the QR23B225 as the modern, direct replacement for new installations. The QR frame shares the same footprint and applications.

No. This circuit breaker is rated for a maximum of 240VAC. Applying it to a 480V system exceeds its dielectric and interrupting design limits, posing a severe electrical hazard.

The QJ23B225 features a unit-mount design, meaning it requires a bolted connection to the bus bar or mounting bracket rather than snapping onto a plug-on stab.

Yes. Because it utilizes a thermal-magnetic trip unit without line or load directional electronics, it is capable of being reverse fed. Ensure you install proper hold-down kits and labeling per NEC if using it as a back-fed main.

Yes. The QJ23B225 is HACR rated, meaning it is certified for use in heating, air conditioning, and refrigeration equipment branch circuits.

Because lug torque requirements vary based on the specific wire gauge and conductor material being installed, you must follow the torque table printed directly on the circuit breaker faceplate to ensure compliance.

Installing the QJ23B225 into a panelboard not explicitly UL-listed for Siemens QJ frames creates a poor mechanical connection. This causes high contact resistance, arcing, overheating, and voids the UL listing of the equipment.