Eaton / Cutler-Hammer QBHW2125 Miniature Circuit Breaker

Both are 125A, 2-pole bolt-on miniature circuit breakers sharing the same physical Quicklag-B frame. The key difference is the interrupting capacity. The BAB2125 is rated for 10kAIC, while the QBHW2125 is rated for 22kAIC at 120/240VAC.

This bolt-on breaker is designed for use in Eaton Pow-R-Line panelboards, such as the PRL1a and PRL1X series. It is also backward compatible with legacy Westinghouse panelboards that accept Quicklag-B frame breakers.

It is built on the standard BAB frame, often referred to as the Quicklag-B frame. This ensures physical compatibility with Eaton and Westinghouse panels designed for 1-inch per pole bolt-on breakers.

It utilizes a bolt-on connection, meaning the breaker physically bolts directly to the panelboard busbar. This provides a highly secure, vibration-resistant electrical connection compared to plug-on designs.

The box lug terminals on this breaker are designed to accept copper (Cu) or aluminum (Al) wire ranging from 4 AWG to 2/0 AWG.

The LI code means the thermal-magnetic trip unit provides both Long-Time (thermal) protection for sustained overloads and Instantaneous (magnetic) protection for immediate short-circuit faults.

Yes. Eaton acquired the Westinghouse distribution equipment line and continues to manufacture the QBHW series as a direct, UL-listed replacement for legacy Westinghouse bolt-on breakers with matching specifications.

Bolt-on breakers provide a more secure mechanical and electrical connection to the busbar. This prevents the breaker from loosening over time due to thermal cycling or vibration, which is critical in commercial and industrial environments.